[15,6/7] libcamera: virtual: Read config and register cameras based on the config

21508 diff mbox series

This patch introduces the configuration file for Virtual Pipeline
Handler. The config file is written in yaml, and the format is
documented in `README.md`.

The config file will define the camera with IDs, supported formats and
image sources, etc. In the default config file, only Test Patterns are
used. Developers can use real images loading if desired.

Signed-off-by: Konami Shu <konamiz@google.com>
Co-developed-by: Harvey Yang <chenghaoyang@chromium.org>
Co-developed-by: Yunke Cao <yunkec@chromium.org>
Co-developed-by: Tomasz Figa <tfiga@chromium.org>
---
 src/libcamera/pipeline/virtual/README.md      |  65 +++++
 .../pipeline/virtual/config_parser.cpp        | 263 ++++++++++++++++++
 .../pipeline/virtual/config_parser.h          |  39 +++
 .../pipeline/virtual/data/virtual.yaml        |  36 +++
 .../virtual/image_frame_generator.cpp         |  16 +-
 .../pipeline/virtual/image_frame_generator.h  |   5 +-
 src/libcamera/pipeline/virtual/meson.build    |   1 +
 src/libcamera/pipeline/virtual/virtual.cpp    | 126 +++++----
 src/libcamera/pipeline/virtual/virtual.h      |  23 +-
 9 files changed, 504 insertions(+), 70 deletions(-)
 create mode 100644 src/libcamera/pipeline/virtual/README.md
 create mode 100644 src/libcamera/pipeline/virtual/config_parser.cpp
 create mode 100644 src/libcamera/pipeline/virtual/config_parser.h
 create mode 100644 src/libcamera/pipeline/virtual/data/virtual.yaml

Friendly ping: This is the last patch that hasn't got a review tag in
the series. Could we finish the review and merge the series recently?
I can upload the last version with commit messages fixed with SoBs.

BR,
Harvey

On Fri, Oct 4, 2024 at 6:00 PM Harvey Yang <chenghaoyang@chromium.org> wrote:
>
> This patch introduces the configuration file for Virtual Pipeline
> Handler. The config file is written in yaml, and the format is
> documented in `README.md`.
>
> The config file will define the camera with IDs, supported formats and
> image sources, etc. In the default config file, only Test Patterns are
> used. Developers can use real images loading if desired.
>
> Signed-off-by: Konami Shu <konamiz@google.com>
> Co-developed-by: Harvey Yang <chenghaoyang@chromium.org>
> Co-developed-by: Yunke Cao <yunkec@chromium.org>
> Co-developed-by: Tomasz Figa <tfiga@chromium.org>
> ---
>  src/libcamera/pipeline/virtual/README.md      |  65 +++++
>  .../pipeline/virtual/config_parser.cpp        | 263 ++++++++++++++++++
>  .../pipeline/virtual/config_parser.h          |  39 +++
>  .../pipeline/virtual/data/virtual.yaml        |  36 +++
>  .../virtual/image_frame_generator.cpp         |  16 +-
>  .../pipeline/virtual/image_frame_generator.h  |   5 +-
>  src/libcamera/pipeline/virtual/meson.build    |   1 +
>  src/libcamera/pipeline/virtual/virtual.cpp    | 126 +++++----
>  src/libcamera/pipeline/virtual/virtual.h      |  23 +-
>  9 files changed, 504 insertions(+), 70 deletions(-)
>  create mode 100644 src/libcamera/pipeline/virtual/README.md
>  create mode 100644 src/libcamera/pipeline/virtual/config_parser.cpp
>  create mode 100644 src/libcamera/pipeline/virtual/config_parser.h
>  create mode 100644 src/libcamera/pipeline/virtual/data/virtual.yaml
>
> diff --git a/src/libcamera/pipeline/virtual/README.md b/src/libcamera/pipeline/virtual/README.md
> new file mode 100644
> index 000000000..5801e79b5
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/README.md
> @@ -0,0 +1,65 @@
> +# Virtual Pipeline Handler
> +
> +Virtual pipeline handler emulates fake external camera(s) on ChromeOS for testing.
> +
> +## Parse config file and register cameras
> +
> +- The config file is located at `src/libcamera/pipeline/virtual/data/virtual.yaml`
> +
> +### Config File Format
> +The config file contains the information about cameras' properties to register.
> +The config file should be a yaml file with dictionary of the cameraIds
> +associated with their properties as top level. The default value will be applied
> +when any property is empty.
> +
> +Each camera block is a dictionary, containing the following keys:
> +- `supported_formats` (list of `VirtualCameraData::Resolution`, optional) :
> +  List of supported resolution and frame rates of the emulated camera
> +    - `width` (`unsigned int`, default=1920): Width of the window resolution.
> +      This needs to be even.
> +    - `height` (`unsigned int`, default=1080): Height of the window resolution.
> +    - `frame_rates` (list of `int`, default=`[30,60]` ): Range of the frame
> +      rate (per second). If the list contains one value, it's the lower bound
> +      and the upper bound. If the list contains two values, the first is the
> +      lower bound and the second is the upper bound. No other number of values
> +      is allowed.
> +- `test_pattern` (`string`): Which test pattern to use as frames. The options
> +  are "bars", "lines". Cannot be set with `frames`.
> +- `frames` (dictionary):
> +  - `path` (`string`): Path to an image, or path to a directory of a series of
> +    images. Cannot be set with `test_pattern`.
> +    - The test patterns are "bars" which means color bars, and "lines" which
> +      means diagonal lines.
> +    - The path to an image has ".jpg" extension.
> +    - The path to a directory ends with "/". The name of the images in the
> +      directory are "{n}.jpg" with {n} is the sequence of images starting with 0.
> +- `location` (`string`, default="front"): The location of the camera. Support
> +  "front" and "back". This is displayed in qcam camera selection window but
> +  this does not change the output.
> +- `model` (`string`, default="Unknown"): The model name of the camera.
> +  This is displayed in qcam camera selection window but this does not change the output.
> +
> +Check `data/virtual.yaml` as the sample config file.
> +
> +### Implementation
> +
> +`Parser` class provides methods to parse the config file to register cameras
> +in Virtual Pipeline Handler. `parseConfigFile()` is exposed to use in
> +Virtual Pipeline Handler.
> +
> +This is the procedure of the Parser class:
> +1. `parseConfigFile()` parses the config file to `YamlObject` using `YamlParser::parse()`.
> +    - Parse the top level of config file which are the camera ids and look into
> +      each camera properties.
> +2. For each camera, `parseCameraConfigData()` returns a camera with the configuration.
> +    - The methods in the next step fill the data with the pointer to the Camera object.
> +    - If the config file contains invalid configuration, this method returns
> +      nullptr. The camera will be skipped.
> +3. Parse each property and register the data.
> +    - `parseSupportedFormats()`: Parses `supported_formats` in the config, which
> +      contains resolutions and frame rates.
> +    - `parseFrameGenerator()`: Parses `test_pattern` or `frames` in the config.
> +    - `parseLocation()`: Parses `location` in the config.
> +    - `parseModel()`: Parses `model` in the config.
> +4. Back to `parseConfigFile()` and append the camera configuration.
> +5. Returns a list of camera configurations.
> diff --git a/src/libcamera/pipeline/virtual/config_parser.cpp b/src/libcamera/pipeline/virtual/config_parser.cpp
> new file mode 100644
> index 000000000..467dde485
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/config_parser.cpp
> @@ -0,0 +1,263 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2024, Google Inc.
> + *
> + * config_parser.cpp - Virtual cameras helper to parse config file
> + */
> +
> +#include "config_parser.h"
> +
> +#include <string.h>
> +#include <utility>
> +
> +#include <libcamera/base/log.h>
> +
> +#include <libcamera/control_ids.h>
> +#include <libcamera/property_ids.h>
> +
> +#include "libcamera/internal/pipeline_handler.h"
> +#include "libcamera/internal/yaml_parser.h"
> +
> +#include "virtual.h"
> +
> +namespace libcamera {
> +
> +LOG_DECLARE_CATEGORY(Virtual)
> +
> +std::vector<std::unique_ptr<VirtualCameraData>>
> +ConfigParser::parseConfigFile(File &file, PipelineHandler *pipe)
> +{
> +       std::vector<std::unique_ptr<VirtualCameraData>> configurations;
> +
> +       std::unique_ptr<YamlObject> cameras = YamlParser::parse(file);
> +       if (!cameras) {
> +               LOG(Virtual, Error) << "Failed to pass config file.";
> +               return configurations;
> +       }
> +
> +       if (!cameras->isDictionary()) {
> +               LOG(Virtual, Error) << "Config file is not a dictionary at the top level.";
> +               return configurations;
> +       }
> +
> +       /* Look into the configuration of each camera */
> +       for (const auto &[cameraId, cameraConfigData] : cameras->asDict()) {
> +               std::unique_ptr<VirtualCameraData> data =
> +                       parseCameraConfigData(cameraConfigData, pipe);
> +               /* Parse configData to data */
> +               if (!data) {
> +                       /* Skip the camera if it has invalid config */
> +                       LOG(Virtual, Error) << "Failed to parse config of the camera: "
> +                                           << cameraId;
> +                       continue;
> +               }
> +
> +               data->config_.id = cameraId;
> +               ControlInfoMap::Map controls;
> +               /* todo: Check which resolution's frame rate to be reported */
> +               controls[&controls::FrameDurationLimits] =
> +                       ControlInfo(1000000 / data->config_.resolutions[0].frameRates[1],
> +                                   1000000 / data->config_.resolutions[0].frameRates[0]);
> +
> +               std::vector<ControlValue> supportedFaceDetectModes{
> +                       static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> +               };
> +               controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> +
> +               data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> +               configurations.push_back(std::move(data));
> +       }
> +
> +       return configurations;
> +}
> +
> +std::unique_ptr<VirtualCameraData>
> +ConfigParser::parseCameraConfigData(const YamlObject &cameraConfigData,
> +                                   PipelineHandler *pipe)
> +{
> +       std::vector<VirtualCameraData::Resolution> resolutions;
> +       if (parseSupportedFormats(cameraConfigData, &resolutions))
> +               return nullptr;
> +
> +       std::unique_ptr<VirtualCameraData> data =
> +               std::make_unique<VirtualCameraData>(pipe, resolutions);
> +
> +       if (parseFrameGenerator(cameraConfigData, data.get()))
> +               return nullptr;
> +
> +       if (parseLocation(cameraConfigData, data.get()))
> +               return nullptr;
> +
> +       if (parseModel(cameraConfigData, data.get()))
> +               return nullptr;
> +
> +       return data;
> +}
> +
> +int ConfigParser::parseSupportedFormats(const YamlObject &cameraConfigData,
> +                                       std::vector<VirtualCameraData::Resolution> *resolutions)
> +{
> +       if (cameraConfigData.contains("supported_formats")) {
> +               const YamlObject &supportedResolutions = cameraConfigData["supported_formats"];
> +
> +               for (const YamlObject &supportedResolution : supportedResolutions.asList()) {
> +                       unsigned int width = supportedResolution["width"].get<unsigned int>(1920);
> +                       unsigned int height = supportedResolution["height"].get<unsigned int>(1080);
> +                       if (width == 0 || height == 0) {
> +                               LOG(Virtual, Error) << "Invalid width or/and height";
> +                               return -EINVAL;
> +                       }
> +                       if (width % 2 != 0) {
> +                               LOG(Virtual, Error) << "Invalid width: width needs to be even";
> +                               return -EINVAL;
> +                       }
> +
> +                       std::vector<int64_t> frameRates;
> +                       if (supportedResolution.contains("frame_rates")) {
> +                               auto frameRatesList =
> +                                       supportedResolution["frame_rates"].getList<int>();
> +                               if (!frameRatesList || (frameRatesList->size() != 1 &&
> +                                                       frameRatesList->size() != 2)) {
> +                                       LOG(Virtual, Error) << "Invalid frame_rates: either one or two values";
> +                                       return -EINVAL;
> +                               }
> +
> +                               if (frameRatesList->size() == 2 &&
> +                                   frameRatesList.value()[0] > frameRatesList.value()[1]) {
> +                                       LOG(Virtual, Error) << "frame_rates's first value(lower bound)"
> +                                                           << " is higher than the second value(upper bound)";
> +                                       return -EINVAL;
> +                               }
> +                               /*
> +                                 * Push the min and max framerates. A
> +                                 * single rate is duplicated.
> +                                 */
> +                               frameRates.push_back(frameRatesList.value().front());
> +                               frameRates.push_back(frameRatesList.value().back());
> +                       } else {
> +                               frameRates.push_back(30);
> +                               frameRates.push_back(60);
> +                       }
> +
> +                       resolutions->emplace_back(
> +                               VirtualCameraData::Resolution{ Size{ width, height },
> +                                                              frameRates });
> +               }
> +       } else {
> +               resolutions->emplace_back(
> +                       VirtualCameraData::Resolution{ Size{ 1920, 1080 },
> +                                                      { 30, 60 } });
> +       }
> +
> +       return 0;
> +}
> +
> +int ConfigParser::parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data)
> +{
> +       const std::string testPatternKey = "test_pattern";
> +       const std::string framesKey = "frames";
> +       if (cameraConfigData.contains(testPatternKey)) {
> +               if (cameraConfigData.contains(framesKey)) {
> +                       LOG(Virtual, Error) << "A camera should use either "
> +                                           << testPatternKey << " or " << framesKey;
> +                       return -EINVAL;
> +               }
> +
> +               auto testPattern = cameraConfigData[testPatternKey].get<std::string>("");
> +
> +               if (testPattern == "bars") {
> +                       data->config_.frame = TestPattern::ColorBars;
> +               } else if (testPattern == "lines") {
> +                       data->config_.frame = TestPattern::DiagonalLines;
> +               } else {
> +                       LOG(Virtual, Debug) << "Test pattern: " << testPattern
> +                                           << " is not supported";
> +                       return -EINVAL;
> +               }
> +
> +               return 0;
> +       }
> +
> +       const YamlObject &frames = cameraConfigData[framesKey];
> +
> +       /* When there is no frames provided in the config file, use color bar test pattern */
> +       if (!frames) {
> +               data->config_.frame = TestPattern::ColorBars;
> +               return 0;
> +       }
> +
> +       if (!frames.isDictionary()) {
> +               LOG(Virtual, Error) << "'frames' is not a dictionary.";
> +               return -EINVAL;
> +       }
> +
> +       auto path = frames["path"].get<std::string>();
> +
> +       if (!path) {
> +               LOG(Virtual, Error) << "Test pattern or path should be specified.";
> +               return -EINVAL;
> +       }
> +
> +       std::vector<std::filesystem::path> files;
> +
> +       switch (std::filesystem::symlink_status(*path).type()) {
> +       case std::filesystem::file_type::regular:
> +               files.push_back(*path);
> +               break;
> +
> +       case std::filesystem::file_type::directory:
> +               for (const auto &dentry : std::filesystem::directory_iterator{ *path }) {
> +                       if (dentry.is_regular_file())
> +                               files.push_back(dentry.path());
> +               }
> +
> +               std::sort(files.begin(), files.end(), [](const auto &a, const auto &b) {
> +                       return ::strverscmp(a.c_str(), b.c_str()) < 0;
> +               });
> +
> +               if (files.empty()) {
> +                       LOG(Virtual, Error) << "Directory has no files: " << *path;
> +                       return -EINVAL;
> +               }
> +               break;
> +
> +       default:
> +               LOG(Virtual, Error) << "Frame: " << *path << " is not supported";
> +               return -EINVAL;
> +       }
> +
> +       data->config_.frame = ImageFrames{ std::move(files) };
> +
> +       return 0;
> +}
> +
> +int ConfigParser::parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data)
> +{
> +       std::string location = cameraConfigData["location"].get<std::string>("front");
> +
> +       /* Default value is properties::CameraLocationFront */
> +       if (location == "front") {
> +               data->properties_.set(properties::Location,
> +                                     properties::CameraLocationFront);
> +       } else if (location == "back") {
> +               data->properties_.set(properties::Location,
> +                                     properties::CameraLocationBack);
> +       } else {
> +               LOG(Virtual, Error) << "location: " << location
> +                                   << " is not supported";
> +               return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
> +int ConfigParser::parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data)
> +{
> +       std::string model = cameraConfigData["model"].get<std::string>("Unknown");
> +
> +       data->properties_.set(properties::Model, model);
> +
> +       return 0;
> +}
> +
> +} /* namespace libcamera */
> diff --git a/src/libcamera/pipeline/virtual/config_parser.h b/src/libcamera/pipeline/virtual/config_parser.h
> new file mode 100644
> index 000000000..9abba62d0
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/config_parser.h
> @@ -0,0 +1,39 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2024, Google Inc.
> + *
> + * config_parser.h - Virtual cameras helper to parse config file
> + */
> +
> +#pragma once
> +
> +#include <memory>
> +#include <vector>
> +
> +#include <libcamera/base/file.h>
> +
> +#include "libcamera/internal/pipeline_handler.h"
> +#include "libcamera/internal/yaml_parser.h"
> +
> +#include "virtual.h"
> +
> +namespace libcamera {
> +
> +class ConfigParser
> +{
> +public:
> +       std::vector<std::unique_ptr<VirtualCameraData>>
> +       parseConfigFile(File &file, PipelineHandler *pipe);
> +
> +private:
> +       std::unique_ptr<VirtualCameraData>
> +       parseCameraConfigData(const YamlObject &cameraConfigData, PipelineHandler *pipe);
> +
> +       int parseSupportedFormats(const YamlObject &cameraConfigData,
> +                                 std::vector<VirtualCameraData::Resolution> *resolutions);
> +       int parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data);
> +       int parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data);
> +       int parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data);
> +};
> +
> +} /* namespace libcamera */
> diff --git a/src/libcamera/pipeline/virtual/data/virtual.yaml b/src/libcamera/pipeline/virtual/data/virtual.yaml
> new file mode 100644
> index 000000000..6b73ddf2b
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/data/virtual.yaml
> @@ -0,0 +1,36 @@
> +# SPDX-License-Identifier: CC0-1.0
> +%YAML 1.1
> +---
> +"Virtual0":
> +  supported_formats:
> +  - width: 1920
> +    height: 1080
> +    frame_rates:
> +    - 30
> +    - 60
> +  - width: 1680
> +    height: 1050
> +    frame_rates:
> +    - 70
> +    - 80
> +  test_pattern: "lines"
> +  location: "front"
> +  model: "Virtual Video Device"
> +"Virtual1":
> +  supported_formats:
> +  - width: 800
> +    height: 600
> +    frame_rates:
> +    - 60
> +  test_pattern: "bars"
> +  location: "back"
> +  model: "Virtual Video Device1"
> +"Virtual2":
> +  supported_formats:
> +  - width: 400
> +    height: 300
> +  test_pattern: "lines"
> +  location: "front"
> +  model: "Virtual Video Device2"
> +"Virtual3":
> +  test_pattern: "bars"
> diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.cpp b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> index 04382beb7..36bdc20e5 100644
> --- a/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> +++ b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> @@ -40,15 +40,7 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
>          * For each file in the directory, load the image,
>          * convert it to NV12, and store the pointer.
>          */
> -       for (unsigned int i = 0; i < imageFrames.number.value_or(1); i++) {
> -               std::filesystem::path path;
> -               if (!imageFrames.number)
> -                       /* If the path is to an image */
> -                       path = imageFrames.path;
> -               else
> -                       /* If the path is to a directory */
> -                       path = imageFrames.path / (std::to_string(i) + ".jpg");
> -
> +       for (std::filesystem::path path : imageFrames.files) {
>                 File file(path);
>                 if (!file.open(File::OpenModeFlag::ReadOnly)) {
>                         LOG(Virtual, Error) << "Failed to open image file " << file.fileName()
> @@ -88,6 +80,8 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
>                                         Size(width, height) });
>         }
>
> +       ASSERT(!imageFrameGenerator->imageFrameDatas_.empty());
> +
>         return imageFrameGenerator;
>  }
>
> @@ -104,7 +98,7 @@ void ImageFrameGenerator::configure(const Size &size)
>         frameIndex_ = 0;
>         parameter_ = 0;
>
> -       for (unsigned int i = 0; i < imageFrames_->number.value_or(1); i++) {
> +       for (unsigned int i = 0; i < imageFrameDatas_.size(); i++) {
>                 /* Scale the imageFrameDatas_ to scaledY and scaledUV */
>                 unsigned int halfSizeWidth = (size.width + 1) / 2;
>                 unsigned int halfSizeHeight = (size.height + 1) / 2;
> @@ -139,7 +133,7 @@ int ImageFrameGenerator::generateFrame(const Size &size, const FrameBuffer *buff
>         auto planes = mappedFrameBuffer.planes();
>
>         /* Loop only around the number of images available */
> -       frameIndex_ %= imageFrames_->number.value_or(1);
> +       frameIndex_ %= imageFrameDatas_.size();
>
>         /* Write the scaledY and scaledUV to the mapped frame buffer */
>         libyuv::NV12Copy(scaledFrameDatas_[frameIndex_].Y.get(), size.width,
> diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.h b/src/libcamera/pipeline/virtual/image_frame_generator.h
> index a68094a66..8554d647d 100644
> --- a/src/libcamera/pipeline/virtual/image_frame_generator.h
> +++ b/src/libcamera/pipeline/virtual/image_frame_generator.h
> @@ -10,9 +10,9 @@
>
>  #include <filesystem>
>  #include <memory>
> -#include <optional>
>  #include <stdint.h>
>  #include <sys/types.h>
> +#include <vector>
>
>  #include "frame_generator.h"
>
> @@ -20,8 +20,7 @@ namespace libcamera {
>
>  /* Frame configuration provided by the config file */
>  struct ImageFrames {
> -       std::filesystem::path path;
> -       std::optional<unsigned int> number;
> +       std::vector<std::filesystem::path> files;
>  };
>
>  class ImageFrameGenerator : public FrameGenerator
> diff --git a/src/libcamera/pipeline/virtual/meson.build b/src/libcamera/pipeline/virtual/meson.build
> index bb38c193c..4786fe2e0 100644
> --- a/src/libcamera/pipeline/virtual/meson.build
> +++ b/src/libcamera/pipeline/virtual/meson.build
> @@ -1,6 +1,7 @@
>  # SPDX-License-Identifier: CC0-1.0
>
>  libcamera_internal_sources += files([
> +    'config_parser.cpp',
>      'image_frame_generator.cpp',
>      'test_pattern_generator.cpp',
>      'virtual.cpp',
> diff --git a/src/libcamera/pipeline/virtual/virtual.cpp b/src/libcamera/pipeline/virtual/virtual.cpp
> index 1ad7417c7..cafd395c3 100644
> --- a/src/libcamera/pipeline/virtual/virtual.cpp
> +++ b/src/libcamera/pipeline/virtual/virtual.cpp
> @@ -36,6 +36,9 @@
>  #include "libcamera/internal/formats.h"
>  #include "libcamera/internal/framebuffer.h"
>  #include "libcamera/internal/pipeline_handler.h"
> +#include "libcamera/internal/yaml_parser.h"
> +
> +#include "pipeline/virtual/config_parser.h"
>
>  namespace libcamera {
>
> @@ -54,6 +57,13 @@ uint64_t currentTimestamp()
>
>  } /* namespace */
>
> +template<class... Ts>
> +struct overloaded : Ts... {
> +       using Ts::operator()...;
> +};
> +template<class... Ts>
> +overloaded(Ts...) -> overloaded<Ts...>;
> +
>  class VirtualCameraConfiguration : public CameraConfiguration
>  {
>  public:
> @@ -95,7 +105,7 @@ private:
>                 return static_cast<VirtualCameraData *>(camera->_d());
>         }
>
> -       void initFrameGenerator(Camera *camera);
> +       bool initFrameGenerator(Camera *camera);
>
>         DmaBufAllocator dmaBufAllocator_;
>
> @@ -104,15 +114,19 @@ private:
>
>  VirtualCameraData::VirtualCameraData(PipelineHandler *pipe,
>                                      const std::vector<Resolution> &supportedResolutions)
> -       : Camera::Private(pipe), supportedResolutions_(supportedResolutions)
> +       : Camera::Private(pipe)
>  {
> -       for (const auto &resolution : supportedResolutions_) {
> -               if (minResolutionSize_.isNull() || minResolutionSize_ > resolution.size)
> -                       minResolutionSize_ = resolution.size;
> +       config_.resolutions = supportedResolutions;
> +       for (const auto &resolution : config_.resolutions) {
> +               if (config_.minResolutionSize.isNull() || config_.minResolutionSize > resolution.size)
> +                       config_.minResolutionSize = resolution.size;
>
> -               maxResolutionSize_ = std::max(maxResolutionSize_, resolution.size);
> +               config_.maxResolutionSize = std::max(config_.maxResolutionSize, resolution.size);
>         }
>
> +       properties_.set(properties::PixelArrayActiveAreas,
> +                       { Rectangle(config_.maxResolutionSize) });
> +
>         /* \todo Support multiple streams and pass multi_stream_test */
>         streamConfigs_.resize(kMaxStream);
>  }
> @@ -140,7 +154,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
>         for (StreamConfiguration &cfg : config_) {
>                 bool adjusted = false;
>                 bool found = false;
> -               for (const auto &resolution : data_->supportedResolutions_) {
> +               for (const auto &resolution : data_->config_.resolutions) {
>                         if (resolution.size.width == cfg.size.width &&
>                             resolution.size.height == cfg.size.height) {
>                                 found = true;
> @@ -155,7 +169,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
>                          * Defining the default logic in PipelineHandler to
>                          * find the closest resolution would be nice.
>                          */
> -                       cfg.size = data_->maxResolutionSize_;
> +                       cfg.size = data_->config_.maxResolutionSize;
>                         status = Adjusted;
>                         adjusted = true;
>                 }
> @@ -224,12 +238,12 @@ PipelineHandlerVirtual::generateConfiguration(Camera *camera,
>
>                 std::map<PixelFormat, std::vector<SizeRange>> streamFormats;
>                 PixelFormat pixelFormat = formats::NV12;
> -               streamFormats[pixelFormat] = { { data->minResolutionSize_,
> -                                                data->maxResolutionSize_ } };
> +               streamFormats[pixelFormat] = { { data->config_.minResolutionSize,
> +                                                data->config_.maxResolutionSize } };
>                 StreamFormats formats(streamFormats);
>                 StreamConfiguration cfg(formats);
>                 cfg.pixelFormat = pixelFormat;
> -               cfg.size = data->maxResolutionSize_;
> +               cfg.size = data->config_.maxResolutionSize;
>                 cfg.bufferCount = VirtualCameraConfiguration::kBufferCount;
>
>                 config->addConfiguration(cfg);
> @@ -246,6 +260,7 @@ int PipelineHandlerVirtual::configure(Camera *camera,
>         VirtualCameraData *data = cameraData(camera);
>         for (auto [i, c] : utils::enumerate(*config)) {
>                 c.setStream(&data->streamConfigs_[i].stream);
> +               /* Start reading the images/generating test patterns */
>                 data->streamConfigs_[i].frameGenerator->configure(c.size);
>         }
>
> @@ -315,56 +330,67 @@ bool PipelineHandlerVirtual::match([[maybe_unused]] DeviceEnumerator *enumerator
>
>         created_ = true;
>
> -       /* \todo Add virtual cameras according to a config file. */
> -
> -       std::vector<VirtualCameraData::Resolution> supportedResolutions;
> -       supportedResolutions.resize(2);
> -       supportedResolutions[0] = { .size = Size(1920, 1080), .frameRates = { 30 } };
> -       supportedResolutions[1] = { .size = Size(1280, 720), .frameRates = { 30 } };
> -
> -       std::unique_ptr<VirtualCameraData> data =
> -               std::make_unique<VirtualCameraData>(this, supportedResolutions);
> -
> -       data->properties_.set(properties::Location, properties::CameraLocationFront);
> -       data->properties_.set(properties::Model, "Virtual Video Device");
> -       data->properties_.set(properties::PixelArrayActiveAreas, { Rectangle(Size(1920, 1080)) });
> -
> -       /* \todo Set FrameDurationLimits based on config. */
> -       ControlInfoMap::Map controls;
> -       int64_t min_frame_duration = 33333, max_frame_duration = 33333;
> -       controls[&controls::FrameDurationLimits] = ControlInfo(min_frame_duration, max_frame_duration);
> -       std::vector<ControlValue> supportedFaceDetectModes{
> -               static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> -       };
> -       controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> -       data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> -
> -       /* Create and register the camera. */
> -       std::set<Stream *> streams;
> -       for (auto &streamConfig : data->streamConfigs_)
> -               streams.insert(&streamConfig.stream);
> +       File file(configurationFile("virtual", "virtual.yaml"));
> +       bool isOpen = file.open(File::OpenModeFlag::ReadOnly);
> +       if (!isOpen) {
> +               LOG(Virtual, Error) << "Failed to open config file: " << file.fileName();
> +               return false;
> +       }
>
> -       const std::string id = "Virtual0";
> -       std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> +       ConfigParser parser;
> +       auto configData = parser.parseConfigFile(file, this);
> +       if (configData.size() == 0) {
> +               LOG(Virtual, Error) << "Failed to parse any cameras from the config file: "
> +                                   << file.fileName();
> +               return false;
> +       }
>
> -       initFrameGenerator(camera.get());
> +       /* Configure and register cameras with configData */
> +       for (auto &data : configData) {
> +               std::set<Stream *> streams;
> +               for (auto &streamConfig : data->streamConfigs_)
> +                       streams.insert(&streamConfig.stream);
> +               std::string id = data->config_.id;
> +               std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> +
> +               if (!initFrameGenerator(camera.get())) {
> +                       LOG(Virtual, Error) << "Failed to initialize frame "
> +                                           << "generator for camera: " << id;
> +                       continue;
> +               }
>
> -       registerCamera(std::move(camera));
> +               registerCamera(std::move(camera));
> +       }
>
>         resetCreated_ = true;
>
>         return true;
>  }
>
> -void PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
> +bool PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
>  {
>         auto data = cameraData(camera);
> -       for (auto &streamConfig : data->streamConfigs_) {
> -               if (data->testPattern_ == TestPattern::DiagonalLines)
> -                       streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> -               else
> -                       streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> -       }
> +       auto &frame = data->config_.frame;
> +       std::visit(overloaded{
> +                          [&](TestPattern &testPattern) {
> +                                  for (auto &streamConfig : data->streamConfigs_) {
> +                                          if (testPattern == TestPattern::DiagonalLines)
> +                                                  streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> +                                          else
> +                                                  streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> +                                  }
> +                          },
> +                          [&](ImageFrames &imageFrames) {
> +                                  for (auto &streamConfig : data->streamConfigs_)
> +                                          streamConfig.frameGenerator = ImageFrameGenerator::create(imageFrames);
> +                          } },
> +                  frame);
> +
> +       for (auto &streamConfig : data->streamConfigs_)
> +               if (!streamConfig.frameGenerator)
> +                       return false;
> +
> +       return true;
>  }
>
>  REGISTER_PIPELINE_HANDLER(PipelineHandlerVirtual, "virtual")
> diff --git a/src/libcamera/pipeline/virtual/virtual.h b/src/libcamera/pipeline/virtual/virtual.h
> index 0b15f8d9c..8c4d6ae64 100644
> --- a/src/libcamera/pipeline/virtual/virtual.h
> +++ b/src/libcamera/pipeline/virtual/virtual.h
> @@ -7,6 +7,8 @@
>
>  #pragma once
>
> +#include <string>
> +#include <variant>
>  #include <vector>
>
>  #include <libcamera/geometry.h>
> @@ -15,10 +17,14 @@
>  #include "libcamera/internal/camera.h"
>  #include "libcamera/internal/pipeline_handler.h"
>
> +#include "frame_generator.h"
> +#include "image_frame_generator.h"
>  #include "test_pattern_generator.h"
>
>  namespace libcamera {
>
> +using VirtualFrame = std::variant<TestPattern, ImageFrames>;
> +
>  class VirtualCameraData : public Camera::Private
>  {
>  public:
> @@ -26,23 +32,28 @@ public:
>
>         struct Resolution {
>                 Size size;
> -               std::vector<int> frameRates;
> +               std::vector<int64_t> frameRates;
>         };
>         struct StreamConfig {
>                 Stream stream;
>                 std::unique_ptr<FrameGenerator> frameGenerator;
>         };
> +       /* The config file is parsed to the Configuration struct */
> +       struct Configuration {
> +               std::string id;
> +               std::vector<Resolution> resolutions;
> +               VirtualFrame frame;
> +
> +               Size maxResolutionSize;
> +               Size minResolutionSize;
> +       };
>
>         VirtualCameraData(PipelineHandler *pipe,
>                           const std::vector<Resolution> &supportedResolutions);
>
>         ~VirtualCameraData() = default;
>
> -       TestPattern testPattern_ = TestPattern::ColorBars;
> -
> -       const std::vector<Resolution> supportedResolutions_;
> -       Size maxResolutionSize_;
> -       Size minResolutionSize_;
> +       Configuration config_;
>
>         std::vector<StreamConfig> streamConfigs_;
>  };
> --
> 2.47.0.rc0.187.ge670bccf7e-goog
>

Quoting Harvey Yang (2024-10-04 10:59:19)
> This patch introduces the configuration file for Virtual Pipeline
> Handler. The config file is written in yaml, and the format is
> documented in `README.md`.
> 
> The config file will define the camera with IDs, supported formats and
> image sources, etc. In the default config file, only Test Patterns are
> used. Developers can use real images loading if desired.
> 
> Signed-off-by: Konami Shu <konamiz@google.com>
> Co-developed-by: Harvey Yang <chenghaoyang@chromium.org>
> Co-developed-by: Yunke Cao <yunkec@chromium.org>
> Co-developed-by: Tomasz Figa <tfiga@chromium.org>

I think we determined Co-developed-by: need SoBs.

Checkstyle reports:

-----------------------------------------------------------------------------------------------------------------
83f896b4afa8e5e7a4029d1e07bcb5dfe8cc5fb2 libcamera: virtual: Read config and register cameras based on the config
-----------------------------------------------------------------------------------------------------------------
No 'Signed-off-by' trailer matching author 'Harvey Yang <chenghaoyang@chromium.org>', see Documentation/contributing.rst
---
1 potential issue detected, please review

And that will apply to all the above.


> ---
>  src/libcamera/pipeline/virtual/README.md      |  65 +++++
>  .../pipeline/virtual/config_parser.cpp        | 263 ++++++++++++++++++
>  .../pipeline/virtual/config_parser.h          |  39 +++
>  .../pipeline/virtual/data/virtual.yaml        |  36 +++
>  .../virtual/image_frame_generator.cpp         |  16 +-
>  .../pipeline/virtual/image_frame_generator.h  |   5 +-
>  src/libcamera/pipeline/virtual/meson.build    |   1 +
>  src/libcamera/pipeline/virtual/virtual.cpp    | 126 +++++----
>  src/libcamera/pipeline/virtual/virtual.h      |  23 +-
>  9 files changed, 504 insertions(+), 70 deletions(-)
>  create mode 100644 src/libcamera/pipeline/virtual/README.md
>  create mode 100644 src/libcamera/pipeline/virtual/config_parser.cpp
>  create mode 100644 src/libcamera/pipeline/virtual/config_parser.h
>  create mode 100644 src/libcamera/pipeline/virtual/data/virtual.yaml
> 
> diff --git a/src/libcamera/pipeline/virtual/README.md b/src/libcamera/pipeline/virtual/README.md
> new file mode 100644
> index 000000000..5801e79b5
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/README.md
> @@ -0,0 +1,65 @@
> +# Virtual Pipeline Handler
> +
> +Virtual pipeline handler emulates fake external camera(s) on ChromeOS for testing.

It's not only on ChromeOS right ? It's just a virtual camera for any
platform.



> +
> +## Parse config file and register cameras
> +
> +- The config file is located at `src/libcamera/pipeline/virtual/data/virtual.yaml`

I'm sure I mentioned this before - but this is the source location.
While I preume the users would have to configure their 'installed'
location. So this should probably reference the fact it would be
installed in ...

Err - where does it get installed ? What happens if libcamera is
installed and tries to use the virtual pipeline handler here ?

I don't see any reference in a meson file that installes
data/virtual.yaml ?


Later on virtual.yaml is mentioned as a sample, while up here it's
specified as '"The" config file'. ? 

Maybe this should say "A sample config file is located at ..."

> +
> +### Config File Format
> +The config file contains the information about cameras' properties to register.
> +The config file should be a yaml file with dictionary of the cameraIds
> +associated with their properties as top level. The default value will be applied
> +when any property is empty.
> +
> +Each camera block is a dictionary, containing the following keys:
> +- `supported_formats` (list of `VirtualCameraData::Resolution`, optional) :
> +  List of supported resolution and frame rates of the emulated camera
> +    - `width` (`unsigned int`, default=1920): Width of the window resolution.
> +      This needs to be even.
> +    - `height` (`unsigned int`, default=1080): Height of the window resolution.
> +    - `frame_rates` (list of `int`, default=`[30,60]` ): Range of the frame
> +      rate (per second). If the list contains one value, it's the lower bound
> +      and the upper bound. If the list contains two values, the first is the
> +      lower bound and the second is the upper bound. No other number of values
> +      is allowed.
> +- `test_pattern` (`string`): Which test pattern to use as frames. The options
> +  are "bars", "lines". Cannot be set with `frames`.
> +- `frames` (dictionary):
> +  - `path` (`string`): Path to an image, or path to a directory of a series of
> +    images. Cannot be set with `test_pattern`.
> +    - The test patterns are "bars" which means color bars, and "lines" which
> +      means diagonal lines.

Does this bullet point belong to the 'test_pattern' section above rather
than frames ? 

> +    - The path to an image has ".jpg" extension.
> +    - The path to a directory ends with "/". The name of the images in the
> +      directory are "{n}.jpg" with {n} is the sequence of images starting with 0.
> +- `location` (`string`, default="front"): The location of the camera. Support
> +  "front" and "back". This is displayed in qcam camera selection window but

I don't think it's relevant to mention 'qcam' here. Setting the location
defines the location property of the camera which is exposed by the
camera in /any/ application. Not just qcam.


> +  this does not change the output.
> +- `model` (`string`, default="Unknown"): The model name of the camera.
> +  This is displayed in qcam camera selection window but this does not change the output.
> +
> +Check `data/virtual.yaml` as the sample config file.
> +
> +### Implementation
> +
> +`Parser` class provides methods to parse the config file to register cameras
> +in Virtual Pipeline Handler. `parseConfigFile()` is exposed to use in
> +Virtual Pipeline Handler.
> +
> +This is the procedure of the Parser class:
> +1. `parseConfigFile()` parses the config file to `YamlObject` using `YamlParser::parse()`.
> +    - Parse the top level of config file which are the camera ids and look into
> +      each camera properties.
> +2. For each camera, `parseCameraConfigData()` returns a camera with the configuration.
> +    - The methods in the next step fill the data with the pointer to the Camera object.
> +    - If the config file contains invalid configuration, this method returns
> +      nullptr. The camera will be skipped.
> +3. Parse each property and register the data.
> +    - `parseSupportedFormats()`: Parses `supported_formats` in the config, which
> +      contains resolutions and frame rates.
> +    - `parseFrameGenerator()`: Parses `test_pattern` or `frames` in the config.
> +    - `parseLocation()`: Parses `location` in the config.
> +    - `parseModel()`: Parses `model` in the config.
> +4. Back to `parseConfigFile()` and append the camera configuration.
> +5. Returns a list of camera configurations.
> diff --git a/src/libcamera/pipeline/virtual/config_parser.cpp b/src/libcamera/pipeline/virtual/config_parser.cpp
> new file mode 100644
> index 000000000..467dde485
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/config_parser.cpp
> @@ -0,0 +1,263 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2024, Google Inc.
> + *
> + * config_parser.cpp - Virtual cameras helper to parse config file

Drop 'config_parser.cpp - ' We stopped putting file names in their own
files as they bitrot and don't add value

> + */
> +
> +#include "config_parser.h"
> +
> +#include <string.h>
> +#include <utility>
> +
> +#include <libcamera/base/log.h>
> +
> +#include <libcamera/control_ids.h>
> +#include <libcamera/property_ids.h>
> +
> +#include "libcamera/internal/pipeline_handler.h"
> +#include "libcamera/internal/yaml_parser.h"
> +
> +#include "virtual.h"
> +
> +namespace libcamera {
> +
> +LOG_DECLARE_CATEGORY(Virtual)
> +
> +std::vector<std::unique_ptr<VirtualCameraData>>
> +ConfigParser::parseConfigFile(File &file, PipelineHandler *pipe)
> +{
> +       std::vector<std::unique_ptr<VirtualCameraData>> configurations;
> +
> +       std::unique_ptr<YamlObject> cameras = YamlParser::parse(file);
> +       if (!cameras) {
> +               LOG(Virtual, Error) << "Failed to pass config file.";
> +               return configurations;
> +       }
> +
> +       if (!cameras->isDictionary()) {
> +               LOG(Virtual, Error) << "Config file is not a dictionary at the top level.";
> +               return configurations;
> +       }
> +
> +       /* Look into the configuration of each camera */
> +       for (const auto &[cameraId, cameraConfigData] : cameras->asDict()) {
> +               std::unique_ptr<VirtualCameraData> data =
> +                       parseCameraConfigData(cameraConfigData, pipe);
> +               /* Parse configData to data */
> +               if (!data) {
> +                       /* Skip the camera if it has invalid config */
> +                       LOG(Virtual, Error) << "Failed to parse config of the camera: "
> +                                           << cameraId;
> +                       continue;
> +               }
> +
> +               data->config_.id = cameraId;
> +               ControlInfoMap::Map controls;
> +               /* todo: Check which resolution's frame rate to be reported */
> +               controls[&controls::FrameDurationLimits] =
> +                       ControlInfo(1000000 / data->config_.resolutions[0].frameRates[1],
> +                                   1000000 / data->config_.resolutions[0].frameRates[0]);
> +
> +               std::vector<ControlValue> supportedFaceDetectModes{
> +                       static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> +               };
> +               controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> +
> +               data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> +               configurations.push_back(std::move(data));
> +       }
> +
> +       return configurations;
> +}
> +
> +std::unique_ptr<VirtualCameraData>
> +ConfigParser::parseCameraConfigData(const YamlObject &cameraConfigData,
> +                                   PipelineHandler *pipe)
> +{
> +       std::vector<VirtualCameraData::Resolution> resolutions;
> +       if (parseSupportedFormats(cameraConfigData, &resolutions))
> +               return nullptr;
> +
> +       std::unique_ptr<VirtualCameraData> data =
> +               std::make_unique<VirtualCameraData>(pipe, resolutions);
> +
> +       if (parseFrameGenerator(cameraConfigData, data.get()))
> +               return nullptr;
> +
> +       if (parseLocation(cameraConfigData, data.get()))
> +               return nullptr;
> +
> +       if (parseModel(cameraConfigData, data.get()))
> +               return nullptr;
> +
> +       return data;
> +}
> +
> +int ConfigParser::parseSupportedFormats(const YamlObject &cameraConfigData,
> +                                       std::vector<VirtualCameraData::Resolution> *resolutions)
> +{
> +       if (cameraConfigData.contains("supported_formats")) {
> +               const YamlObject &supportedResolutions = cameraConfigData["supported_formats"];
> +
> +               for (const YamlObject &supportedResolution : supportedResolutions.asList()) {
> +                       unsigned int width = supportedResolution["width"].get<unsigned int>(1920);
> +                       unsigned int height = supportedResolution["height"].get<unsigned int>(1080);
> +                       if (width == 0 || height == 0) {
> +                               LOG(Virtual, Error) << "Invalid width or/and height";
> +                               return -EINVAL;
> +                       }
> +                       if (width % 2 != 0) {
> +                               LOG(Virtual, Error) << "Invalid width: width needs to be even";
> +                               return -EINVAL;
> +                       }
> +
> +                       std::vector<int64_t> frameRates;
> +                       if (supportedResolution.contains("frame_rates")) {
> +                               auto frameRatesList =
> +                                       supportedResolution["frame_rates"].getList<int>();
> +                               if (!frameRatesList || (frameRatesList->size() != 1 &&
> +                                                       frameRatesList->size() != 2)) {
> +                                       LOG(Virtual, Error) << "Invalid frame_rates: either one or two values";
> +                                       return -EINVAL;
> +                               }
> +
> +                               if (frameRatesList->size() == 2 &&
> +                                   frameRatesList.value()[0] > frameRatesList.value()[1]) {
> +                                       LOG(Virtual, Error) << "frame_rates's first value(lower bound)"
> +                                                           << " is higher than the second value(upper bound)";
> +                                       return -EINVAL;
> +                               }
> +                               /*
> +                                 * Push the min and max framerates. A
> +                                 * single rate is duplicated.
> +                                 */
> +                               frameRates.push_back(frameRatesList.value().front());
> +                               frameRates.push_back(frameRatesList.value().back());
> +                       } else {
> +                               frameRates.push_back(30);
> +                               frameRates.push_back(60);
> +                       }
> +
> +                       resolutions->emplace_back(
> +                               VirtualCameraData::Resolution{ Size{ width, height },
> +                                                              frameRates });
> +               }
> +       } else {
> +               resolutions->emplace_back(
> +                       VirtualCameraData::Resolution{ Size{ 1920, 1080 },
> +                                                      { 30, 60 } });
> +       }
> +
> +       return 0;
> +}
> +
> +int ConfigParser::parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data)
> +{
> +       const std::string testPatternKey = "test_pattern";
> +       const std::string framesKey = "frames";
> +       if (cameraConfigData.contains(testPatternKey)) {
> +               if (cameraConfigData.contains(framesKey)) {
> +                       LOG(Virtual, Error) << "A camera should use either "
> +                                           << testPatternKey << " or " << framesKey;
> +                       return -EINVAL;
> +               }
> +
> +               auto testPattern = cameraConfigData[testPatternKey].get<std::string>("");
> +
> +               if (testPattern == "bars") {
> +                       data->config_.frame = TestPattern::ColorBars;
> +               } else if (testPattern == "lines") {
> +                       data->config_.frame = TestPattern::DiagonalLines;
> +               } else {
> +                       LOG(Virtual, Debug) << "Test pattern: " << testPattern
> +                                           << " is not supported";
> +                       return -EINVAL;
> +               }
> +
> +               return 0;
> +       }
> +
> +       const YamlObject &frames = cameraConfigData[framesKey];
> +
> +       /* When there is no frames provided in the config file, use color bar test pattern */
> +       if (!frames) {
> +               data->config_.frame = TestPattern::ColorBars;
> +               return 0;
> +       }
> +
> +       if (!frames.isDictionary()) {
> +               LOG(Virtual, Error) << "'frames' is not a dictionary.";
> +               return -EINVAL;
> +       }
> +
> +       auto path = frames["path"].get<std::string>();
> +
> +       if (!path) {
> +               LOG(Virtual, Error) << "Test pattern or path should be specified.";
> +               return -EINVAL;
> +       }
> +
> +       std::vector<std::filesystem::path> files;
> +
> +       switch (std::filesystem::symlink_status(*path).type()) {
> +       case std::filesystem::file_type::regular:
> +               files.push_back(*path);
> +               break;
> +
> +       case std::filesystem::file_type::directory:
> +               for (const auto &dentry : std::filesystem::directory_iterator{ *path }) {
> +                       if (dentry.is_regular_file())
> +                               files.push_back(dentry.path());
> +               }
> +
> +               std::sort(files.begin(), files.end(), [](const auto &a, const auto &b) {
> +                       return ::strverscmp(a.c_str(), b.c_str()) < 0;
> +               });
> +
> +               if (files.empty()) {
> +                       LOG(Virtual, Error) << "Directory has no files: " << *path;
> +                       return -EINVAL;
> +               }
> +               break;
> +
> +       default:
> +               LOG(Virtual, Error) << "Frame: " << *path << " is not supported";
> +               return -EINVAL;
> +       }
> +
> +       data->config_.frame = ImageFrames{ std::move(files) };
> +
> +       return 0;
> +}
> +
> +int ConfigParser::parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data)
> +{
> +       std::string location = cameraConfigData["location"].get<std::string>("front");
> +
> +       /* Default value is properties::CameraLocationFront */
> +       if (location == "front") {
> +               data->properties_.set(properties::Location,
> +                                     properties::CameraLocationFront);
> +       } else if (location == "back") {
> +               data->properties_.set(properties::Location,
> +                                     properties::CameraLocationBack);
> +       } else {
> +               LOG(Virtual, Error) << "location: " << location
> +                                   << " is not supported";

What about external ? 

I think the control framework provides a map of string to id for the
enum types in fact, so you can do something like:
	

int ConfigParser::parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data)
{
        std::string location = cameraConfigData["location"].get<std::string>("front");

        auto it = properties::LocationNameValueMap.find(location);
        if (it == properties::LocationNameValueMap.end()) {
                LOG(Virtual, Error)
                       << "location: " << location << " is not supported";

                return -EINVAL;
        }

        data->properties_.set(properties::Location, it->second);

        return 0;
}

Which is probably more future proof too if we for some reason add any
other locations.



> +               return -EINVAL;
> +       }
> +
> +       return 0;
> +}
> +
> +int ConfigParser::parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data)
> +{
> +       std::string model = cameraConfigData["model"].get<std::string>("Unknown");
> +
> +       data->properties_.set(properties::Model, model);
> +
> +       return 0;
> +}
> +
> +} /* namespace libcamera */
> diff --git a/src/libcamera/pipeline/virtual/config_parser.h b/src/libcamera/pipeline/virtual/config_parser.h
> new file mode 100644
> index 000000000..9abba62d0
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/config_parser.h
> @@ -0,0 +1,39 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2024, Google Inc.
> + *
> + * config_parser.h - Virtual cameras helper to parse config file

Drop 'config_parser.h - ' from here.

> + */
> +
> +#pragma once
> +
> +#include <memory>
> +#include <vector>
> +
> +#include <libcamera/base/file.h>
> +
> +#include "libcamera/internal/pipeline_handler.h"
> +#include "libcamera/internal/yaml_parser.h"
> +
> +#include "virtual.h"
> +
> +namespace libcamera {
> +
> +class ConfigParser
> +{
> +public:
> +       std::vector<std::unique_ptr<VirtualCameraData>>
> +       parseConfigFile(File &file, PipelineHandler *pipe);
> +
> +private:
> +       std::unique_ptr<VirtualCameraData>
> +       parseCameraConfigData(const YamlObject &cameraConfigData, PipelineHandler *pipe);
> +
> +       int parseSupportedFormats(const YamlObject &cameraConfigData,
> +                                 std::vector<VirtualCameraData::Resolution> *resolutions);
> +       int parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data);
> +       int parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data);
> +       int parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data);
> +};
> +
> +} /* namespace libcamera */
> diff --git a/src/libcamera/pipeline/virtual/data/virtual.yaml b/src/libcamera/pipeline/virtual/data/virtual.yaml
> new file mode 100644
> index 000000000..6b73ddf2b
> --- /dev/null
> +++ b/src/libcamera/pipeline/virtual/data/virtual.yaml
> @@ -0,0 +1,36 @@
> +# SPDX-License-Identifier: CC0-1.0
> +%YAML 1.1
> +---
> +"Virtual0":
> +  supported_formats:
> +  - width: 1920
> +    height: 1080
> +    frame_rates:
> +    - 30
> +    - 60
> +  - width: 1680
> +    height: 1050
> +    frame_rates:
> +    - 70
> +    - 80
> +  test_pattern: "lines"
> +  location: "front"
> +  model: "Virtual Video Device"
> +"Virtual1":
> +  supported_formats:
> +  - width: 800
> +    height: 600
> +    frame_rates:
> +    - 60
> +  test_pattern: "bars"
> +  location: "back"
> +  model: "Virtual Video Device1"
> +"Virtual2":
> +  supported_formats:
> +  - width: 400
> +    height: 300
> +  test_pattern: "lines"
> +  location: "front"
> +  model: "Virtual Video Device2"
> +"Virtual3":
> +  test_pattern: "bars"
> diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.cpp b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> index 04382beb7..36bdc20e5 100644
> --- a/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> +++ b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> @@ -40,15 +40,7 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
>          * For each file in the directory, load the image,
>          * convert it to NV12, and store the pointer.
>          */
> -       for (unsigned int i = 0; i < imageFrames.number.value_or(1); i++) {
> -               std::filesystem::path path;
> -               if (!imageFrames.number)
> -                       /* If the path is to an image */
> -                       path = imageFrames.path;
> -               else
> -                       /* If the path is to a directory */
> -                       path = imageFrames.path / (std::to_string(i) + ".jpg");
> -
> +       for (std::filesystem::path path : imageFrames.files) {
>                 File file(path);
>                 if (!file.open(File::OpenModeFlag::ReadOnly)) {
>                         LOG(Virtual, Error) << "Failed to open image file " << file.fileName()
> @@ -88,6 +80,8 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
>                                         Size(width, height) });
>         }
>  
> +       ASSERT(!imageFrameGenerator->imageFrameDatas_.empty());
> +
>         return imageFrameGenerator;
>  }
>  
> @@ -104,7 +98,7 @@ void ImageFrameGenerator::configure(const Size &size)
>         frameIndex_ = 0;
>         parameter_ = 0;
>  
> -       for (unsigned int i = 0; i < imageFrames_->number.value_or(1); i++) {
> +       for (unsigned int i = 0; i < imageFrameDatas_.size(); i++) {
>                 /* Scale the imageFrameDatas_ to scaledY and scaledUV */
>                 unsigned int halfSizeWidth = (size.width + 1) / 2;
>                 unsigned int halfSizeHeight = (size.height + 1) / 2;
> @@ -139,7 +133,7 @@ int ImageFrameGenerator::generateFrame(const Size &size, const FrameBuffer *buff
>         auto planes = mappedFrameBuffer.planes();
>  
>         /* Loop only around the number of images available */
> -       frameIndex_ %= imageFrames_->number.value_or(1);
> +       frameIndex_ %= imageFrameDatas_.size();
>  
>         /* Write the scaledY and scaledUV to the mapped frame buffer */
>         libyuv::NV12Copy(scaledFrameDatas_[frameIndex_].Y.get(), size.width,
> diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.h b/src/libcamera/pipeline/virtual/image_frame_generator.h
> index a68094a66..8554d647d 100644
> --- a/src/libcamera/pipeline/virtual/image_frame_generator.h
> +++ b/src/libcamera/pipeline/virtual/image_frame_generator.h
> @@ -10,9 +10,9 @@
>  
>  #include <filesystem>
>  #include <memory>
> -#include <optional>
>  #include <stdint.h>
>  #include <sys/types.h>
> +#include <vector>
>  
>  #include "frame_generator.h"
>  
> @@ -20,8 +20,7 @@ namespace libcamera {
>  
>  /* Frame configuration provided by the config file */
>  struct ImageFrames {
> -       std::filesystem::path path;
> -       std::optional<unsigned int> number;
> +       std::vector<std::filesystem::path> files;
>  };
>  
>  class ImageFrameGenerator : public FrameGenerator
> diff --git a/src/libcamera/pipeline/virtual/meson.build b/src/libcamera/pipeline/virtual/meson.build
> index bb38c193c..4786fe2e0 100644
> --- a/src/libcamera/pipeline/virtual/meson.build
> +++ b/src/libcamera/pipeline/virtual/meson.build
> @@ -1,6 +1,7 @@
>  # SPDX-License-Identifier: CC0-1.0
>  
>  libcamera_internal_sources += files([
> +    'config_parser.cpp',
>      'image_frame_generator.cpp',
>      'test_pattern_generator.cpp',
>      'virtual.cpp',
> diff --git a/src/libcamera/pipeline/virtual/virtual.cpp b/src/libcamera/pipeline/virtual/virtual.cpp
> index 1ad7417c7..cafd395c3 100644
> --- a/src/libcamera/pipeline/virtual/virtual.cpp
> +++ b/src/libcamera/pipeline/virtual/virtual.cpp
> @@ -36,6 +36,9 @@
>  #include "libcamera/internal/formats.h"
>  #include "libcamera/internal/framebuffer.h"
>  #include "libcamera/internal/pipeline_handler.h"
> +#include "libcamera/internal/yaml_parser.h"
> +
> +#include "pipeline/virtual/config_parser.h"
>  
>  namespace libcamera {
>  
> @@ -54,6 +57,13 @@ uint64_t currentTimestamp()
>  
>  } /* namespace */
>  
> +template<class... Ts>
> +struct overloaded : Ts... {
> +       using Ts::operator()...;
> +};
> +template<class... Ts>
> +overloaded(Ts...) -> overloaded<Ts...>;
> +
>  class VirtualCameraConfiguration : public CameraConfiguration
>  {
>  public:
> @@ -95,7 +105,7 @@ private:
>                 return static_cast<VirtualCameraData *>(camera->_d());
>         }
>  
> -       void initFrameGenerator(Camera *camera);
> +       bool initFrameGenerator(Camera *camera);
>  
>         DmaBufAllocator dmaBufAllocator_;
>  
> @@ -104,15 +114,19 @@ private:
>  
>  VirtualCameraData::VirtualCameraData(PipelineHandler *pipe,
>                                      const std::vector<Resolution> &supportedResolutions)
> -       : Camera::Private(pipe), supportedResolutions_(supportedResolutions)
> +       : Camera::Private(pipe)
>  {
> -       for (const auto &resolution : supportedResolutions_) {
> -               if (minResolutionSize_.isNull() || minResolutionSize_ > resolution.size)
> -                       minResolutionSize_ = resolution.size;
> +       config_.resolutions = supportedResolutions;
> +       for (const auto &resolution : config_.resolutions) {
> +               if (config_.minResolutionSize.isNull() || config_.minResolutionSize > resolution.size)
> +                       config_.minResolutionSize = resolution.size;
>  
> -               maxResolutionSize_ = std::max(maxResolutionSize_, resolution.size);
> +               config_.maxResolutionSize = std::max(config_.maxResolutionSize, resolution.size);
>         }
>  
> +       properties_.set(properties::PixelArrayActiveAreas,
> +                       { Rectangle(config_.maxResolutionSize) });
> +
>         /* \todo Support multiple streams and pass multi_stream_test */
>         streamConfigs_.resize(kMaxStream);
>  }
> @@ -140,7 +154,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
>         for (StreamConfiguration &cfg : config_) {
>                 bool adjusted = false;
>                 bool found = false;
> -               for (const auto &resolution : data_->supportedResolutions_) {
> +               for (const auto &resolution : data_->config_.resolutions) {
>                         if (resolution.size.width == cfg.size.width &&
>                             resolution.size.height == cfg.size.height) {
>                                 found = true;
> @@ -155,7 +169,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
>                          * Defining the default logic in PipelineHandler to
>                          * find the closest resolution would be nice.
>                          */
> -                       cfg.size = data_->maxResolutionSize_;
> +                       cfg.size = data_->config_.maxResolutionSize;
>                         status = Adjusted;
>                         adjusted = true;
>                 }
> @@ -224,12 +238,12 @@ PipelineHandlerVirtual::generateConfiguration(Camera *camera,
>  
>                 std::map<PixelFormat, std::vector<SizeRange>> streamFormats;
>                 PixelFormat pixelFormat = formats::NV12;
> -               streamFormats[pixelFormat] = { { data->minResolutionSize_,
> -                                                data->maxResolutionSize_ } };
> +               streamFormats[pixelFormat] = { { data->config_.minResolutionSize,
> +                                                data->config_.maxResolutionSize } };
>                 StreamFormats formats(streamFormats);
>                 StreamConfiguration cfg(formats);
>                 cfg.pixelFormat = pixelFormat;
> -               cfg.size = data->maxResolutionSize_;
> +               cfg.size = data->config_.maxResolutionSize;
>                 cfg.bufferCount = VirtualCameraConfiguration::kBufferCount;
>  
>                 config->addConfiguration(cfg);
> @@ -246,6 +260,7 @@ int PipelineHandlerVirtual::configure(Camera *camera,
>         VirtualCameraData *data = cameraData(camera);
>         for (auto [i, c] : utils::enumerate(*config)) {
>                 c.setStream(&data->streamConfigs_[i].stream);
> +               /* Start reading the images/generating test patterns */
>                 data->streamConfigs_[i].frameGenerator->configure(c.size);
>         }
>  
> @@ -315,56 +330,67 @@ bool PipelineHandlerVirtual::match([[maybe_unused]] DeviceEnumerator *enumerator
>  
>         created_ = true;
>  
> -       /* \todo Add virtual cameras according to a config file. */
> -
> -       std::vector<VirtualCameraData::Resolution> supportedResolutions;
> -       supportedResolutions.resize(2);
> -       supportedResolutions[0] = { .size = Size(1920, 1080), .frameRates = { 30 } };
> -       supportedResolutions[1] = { .size = Size(1280, 720), .frameRates = { 30 } };
> -
> -       std::unique_ptr<VirtualCameraData> data =
> -               std::make_unique<VirtualCameraData>(this, supportedResolutions);
> -
> -       data->properties_.set(properties::Location, properties::CameraLocationFront);
> -       data->properties_.set(properties::Model, "Virtual Video Device");
> -       data->properties_.set(properties::PixelArrayActiveAreas, { Rectangle(Size(1920, 1080)) });
> -
> -       /* \todo Set FrameDurationLimits based on config. */
> -       ControlInfoMap::Map controls;
> -       int64_t min_frame_duration = 33333, max_frame_duration = 33333;
> -       controls[&controls::FrameDurationLimits] = ControlInfo(min_frame_duration, max_frame_duration);
> -       std::vector<ControlValue> supportedFaceDetectModes{
> -               static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> -       };
> -       controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> -       data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> -
> -       /* Create and register the camera. */
> -       std::set<Stream *> streams;
> -       for (auto &streamConfig : data->streamConfigs_)
> -               streams.insert(&streamConfig.stream);
> +       File file(configurationFile("virtual", "virtual.yaml"));

This tells me that the sample virtual.yaml file should probably be
installed in the libcamera data path...

This version doesn't currently apply cleanly to master, but I did have
an branch with it on - and it rebased easily.

But it needs a new version posting at least to solve the SoB issues and
so with the above tackled you can add 

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>


> +       bool isOpen = file.open(File::OpenModeFlag::ReadOnly);
> +       if (!isOpen) {
> +               LOG(Virtual, Error) << "Failed to open config file: " << file.fileName();
> +               return false;
> +       }
>  
> -       const std::string id = "Virtual0";
> -       std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> +       ConfigParser parser;
> +       auto configData = parser.parseConfigFile(file, this);
> +       if (configData.size() == 0) {
> +               LOG(Virtual, Error) << "Failed to parse any cameras from the config file: "
> +                                   << file.fileName();
> +               return false;
> +       }
>  
> -       initFrameGenerator(camera.get());
> +       /* Configure and register cameras with configData */
> +       for (auto &data : configData) {
> +               std::set<Stream *> streams;
> +               for (auto &streamConfig : data->streamConfigs_)
> +                       streams.insert(&streamConfig.stream);
> +               std::string id = data->config_.id;
> +               std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> +
> +               if (!initFrameGenerator(camera.get())) {
> +                       LOG(Virtual, Error) << "Failed to initialize frame "
> +                                           << "generator for camera: " << id;
> +                       continue;
> +               }
>  
> -       registerCamera(std::move(camera));
> +               registerCamera(std::move(camera));
> +       }
>  
>         resetCreated_ = true;
>  
>         return true;
>  }
>  
> -void PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
> +bool PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
>  {
>         auto data = cameraData(camera);
> -       for (auto &streamConfig : data->streamConfigs_) {
> -               if (data->testPattern_ == TestPattern::DiagonalLines)
> -                       streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> -               else
> -                       streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> -       }
> +       auto &frame = data->config_.frame;
> +       std::visit(overloaded{
> +                          [&](TestPattern &testPattern) {
> +                                  for (auto &streamConfig : data->streamConfigs_) {
> +                                          if (testPattern == TestPattern::DiagonalLines)
> +                                                  streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> +                                          else
> +                                                  streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> +                                  }
> +                          },
> +                          [&](ImageFrames &imageFrames) {
> +                                  for (auto &streamConfig : data->streamConfigs_)
> +                                          streamConfig.frameGenerator = ImageFrameGenerator::create(imageFrames);
> +                          } },
> +                  frame);
> +
> +       for (auto &streamConfig : data->streamConfigs_)
> +               if (!streamConfig.frameGenerator)
> +                       return false;
> +
> +       return true;
>  }
>  
>  REGISTER_PIPELINE_HANDLER(PipelineHandlerVirtual, "virtual")
> diff --git a/src/libcamera/pipeline/virtual/virtual.h b/src/libcamera/pipeline/virtual/virtual.h
> index 0b15f8d9c..8c4d6ae64 100644
> --- a/src/libcamera/pipeline/virtual/virtual.h
> +++ b/src/libcamera/pipeline/virtual/virtual.h
> @@ -7,6 +7,8 @@
>  
>  #pragma once
>  
> +#include <string>
> +#include <variant>
>  #include <vector>
>  
>  #include <libcamera/geometry.h>
> @@ -15,10 +17,14 @@
>  #include "libcamera/internal/camera.h"
>  #include "libcamera/internal/pipeline_handler.h"
>  
> +#include "frame_generator.h"
> +#include "image_frame_generator.h"
>  #include "test_pattern_generator.h"
>  
>  namespace libcamera {
>  
> +using VirtualFrame = std::variant<TestPattern, ImageFrames>;
> +
>  class VirtualCameraData : public Camera::Private
>  {
>  public:
> @@ -26,23 +32,28 @@ public:
>  
>         struct Resolution {
>                 Size size;
> -               std::vector<int> frameRates;
> +               std::vector<int64_t> frameRates;
>         };
>         struct StreamConfig {
>                 Stream stream;
>                 std::unique_ptr<FrameGenerator> frameGenerator;
>         };
> +       /* The config file is parsed to the Configuration struct */
> +       struct Configuration {
> +               std::string id;
> +               std::vector<Resolution> resolutions;
> +               VirtualFrame frame;
> +
> +               Size maxResolutionSize;
> +               Size minResolutionSize;
> +       };
>  
>         VirtualCameraData(PipelineHandler *pipe,
>                           const std::vector<Resolution> &supportedResolutions);
>  
>         ~VirtualCameraData() = default;
>  
> -       TestPattern testPattern_ = TestPattern::ColorBars;
> -
> -       const std::vector<Resolution> supportedResolutions_;
> -       Size maxResolutionSize_;
> -       Size minResolutionSize_;
> +       Configuration config_;
>  
>         std::vector<StreamConfig> streamConfigs_;
>  };
> -- 
> 2.47.0.rc0.187.ge670bccf7e-goog
>

Hi Kieran,

On Tue, Oct 22, 2024 at 7:31 AM Kieran Bingham
<kieran.bingham@ideasonboard.com> wrote:
>
> Quoting Harvey Yang (2024-10-04 10:59:19)
> > This patch introduces the configuration file for Virtual Pipeline
> > Handler. The config file is written in yaml, and the format is
> > documented in `README.md`.
> >
> > The config file will define the camera with IDs, supported formats and
> > image sources, etc. In the default config file, only Test Patterns are
> > used. Developers can use real images loading if desired.
> >
> > Signed-off-by: Konami Shu <konamiz@google.com>
> > Co-developed-by: Harvey Yang <chenghaoyang@chromium.org>
> > Co-developed-by: Yunke Cao <yunkec@chromium.org>
> > Co-developed-by: Tomasz Figa <tfiga@chromium.org>
>
> I think we determined Co-developed-by: need SoBs.

Yes, updated. I didn't upload a new version to avoid the spam.

>
> Checkstyle reports:
>
> -----------------------------------------------------------------------------------------------------------------
> 83f896b4afa8e5e7a4029d1e07bcb5dfe8cc5fb2 libcamera: virtual: Read config and register cameras based on the config
> -----------------------------------------------------------------------------------------------------------------
> No 'Signed-off-by' trailer matching author 'Harvey Yang <chenghaoyang@chromium.org>', see Documentation/contributing.rst
> ---
> 1 potential issue detected, please review
>
> And that will apply to all the above.

Done.

>
>
> > ---
> >  src/libcamera/pipeline/virtual/README.md      |  65 +++++
> >  .../pipeline/virtual/config_parser.cpp        | 263 ++++++++++++++++++
> >  .../pipeline/virtual/config_parser.h          |  39 +++
> >  .../pipeline/virtual/data/virtual.yaml        |  36 +++
> >  .../virtual/image_frame_generator.cpp         |  16 +-
> >  .../pipeline/virtual/image_frame_generator.h  |   5 +-
> >  src/libcamera/pipeline/virtual/meson.build    |   1 +
> >  src/libcamera/pipeline/virtual/virtual.cpp    | 126 +++++----
> >  src/libcamera/pipeline/virtual/virtual.h      |  23 +-
> >  9 files changed, 504 insertions(+), 70 deletions(-)
> >  create mode 100644 src/libcamera/pipeline/virtual/README.md
> >  create mode 100644 src/libcamera/pipeline/virtual/config_parser.cpp
> >  create mode 100644 src/libcamera/pipeline/virtual/config_parser.h
> >  create mode 100644 src/libcamera/pipeline/virtual/data/virtual.yaml
> >
> > diff --git a/src/libcamera/pipeline/virtual/README.md b/src/libcamera/pipeline/virtual/README.md
> > new file mode 100644
> > index 000000000..5801e79b5
> > --- /dev/null
> > +++ b/src/libcamera/pipeline/virtual/README.md
> > @@ -0,0 +1,65 @@
> > +# Virtual Pipeline Handler
> > +
> > +Virtual pipeline handler emulates fake external camera(s) on ChromeOS for testing.
>
> It's not only on ChromeOS right ? It's just a virtual camera for any
> platform.

Right, removed.

>
>
>
> > +
> > +## Parse config file and register cameras
> > +
> > +- The config file is located at `src/libcamera/pipeline/virtual/data/virtual.yaml`
>
> I'm sure I mentioned this before - but this is the source location.
> While I preume the users would have to configure their 'installed'
> location. So this should probably reference the fact it would be
> installed in ...
>
> Err - where does it get installed ? What happens if libcamera is
> installed and tries to use the virtual pipeline handler here ?
>
> I don't see any reference in a meson file that installes
> data/virtual.yaml ?
>
>
> Later on virtual.yaml is mentioned as a sample, while up here it's
> specified as '"The" config file'. ?
>
> Maybe this should say "A sample config file is located at ..."

Yes, it depends on if libcamera is installed. Updated and added
the installed path:
`shar/libcamera/pipeline/virtual/virtual.yaml`.

>
> > +
> > +### Config File Format
> > +The config file contains the information about cameras' properties to register.
> > +The config file should be a yaml file with dictionary of the cameraIds
> > +associated with their properties as top level. The default value will be applied
> > +when any property is empty.
> > +
> > +Each camera block is a dictionary, containing the following keys:
> > +- `supported_formats` (list of `VirtualCameraData::Resolution`, optional) :
> > +  List of supported resolution and frame rates of the emulated camera
> > +    - `width` (`unsigned int`, default=1920): Width of the window resolution.
> > +      This needs to be even.
> > +    - `height` (`unsigned int`, default=1080): Height of the window resolution.
> > +    - `frame_rates` (list of `int`, default=`[30,60]` ): Range of the frame
> > +      rate (per second). If the list contains one value, it's the lower bound
> > +      and the upper bound. If the list contains two values, the first is the
> > +      lower bound and the second is the upper bound. No other number of values
> > +      is allowed.
> > +- `test_pattern` (`string`): Which test pattern to use as frames. The options
> > +  are "bars", "lines". Cannot be set with `frames`.
> > +- `frames` (dictionary):
> > +  - `path` (`string`): Path to an image, or path to a directory of a series of
> > +    images. Cannot be set with `test_pattern`.
> > +    - The test patterns are "bars" which means color bars, and "lines" which
> > +      means diagonal lines.
>
> Does this bullet point belong to the 'test_pattern' section above rather
> than frames ?

Right, thanks! Updated.

>
> > +    - The path to an image has ".jpg" extension.
> > +    - The path to a directory ends with "/". The name of the images in the
> > +      directory are "{n}.jpg" with {n} is the sequence of images starting with 0.
> > +- `location` (`string`, default="front"): The location of the camera. Support
> > +  "front" and "back". This is displayed in qcam camera selection window but
>
> I don't think it's relevant to mention 'qcam' here. Setting the location
> defines the location property of the camera which is exposed by the
> camera in /any/ application. Not just qcam.

Right, removed this and the one in `model`.

>
>
> > +  this does not change the output.
> > +- `model` (`string`, default="Unknown"): The model name of the camera.
> > +  This is displayed in qcam camera selection window but this does not change the output.
> > +
> > +Check `data/virtual.yaml` as the sample config file.
> > +
> > +### Implementation
> > +
> > +`Parser` class provides methods to parse the config file to register cameras
> > +in Virtual Pipeline Handler. `parseConfigFile()` is exposed to use in
> > +Virtual Pipeline Handler.
> > +
> > +This is the procedure of the Parser class:
> > +1. `parseConfigFile()` parses the config file to `YamlObject` using `YamlParser::parse()`.
> > +    - Parse the top level of config file which are the camera ids and look into
> > +      each camera properties.
> > +2. For each camera, `parseCameraConfigData()` returns a camera with the configuration.
> > +    - The methods in the next step fill the data with the pointer to the Camera object.
> > +    - If the config file contains invalid configuration, this method returns
> > +      nullptr. The camera will be skipped.
> > +3. Parse each property and register the data.
> > +    - `parseSupportedFormats()`: Parses `supported_formats` in the config, which
> > +      contains resolutions and frame rates.
> > +    - `parseFrameGenerator()`: Parses `test_pattern` or `frames` in the config.
> > +    - `parseLocation()`: Parses `location` in the config.
> > +    - `parseModel()`: Parses `model` in the config.
> > +4. Back to `parseConfigFile()` and append the camera configuration.
> > +5. Returns a list of camera configurations.
> > diff --git a/src/libcamera/pipeline/virtual/config_parser.cpp b/src/libcamera/pipeline/virtual/config_parser.cpp
> > new file mode 100644
> > index 000000000..467dde485
> > --- /dev/null
> > +++ b/src/libcamera/pipeline/virtual/config_parser.cpp
> > @@ -0,0 +1,263 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2024, Google Inc.
> > + *
> > + * config_parser.cpp - Virtual cameras helper to parse config file
>
> Drop 'config_parser.cpp - ' We stopped putting file names in their own
> files as they bitrot and don't add value

Done

>
> > + */
> > +
> > +#include "config_parser.h"
> > +
> > +#include <string.h>
> > +#include <utility>
> > +
> > +#include <libcamera/base/log.h>
> > +
> > +#include <libcamera/control_ids.h>
> > +#include <libcamera/property_ids.h>
> > +
> > +#include "libcamera/internal/pipeline_handler.h"
> > +#include "libcamera/internal/yaml_parser.h"
> > +
> > +#include "virtual.h"
> > +
> > +namespace libcamera {
> > +
> > +LOG_DECLARE_CATEGORY(Virtual)
> > +
> > +std::vector<std::unique_ptr<VirtualCameraData>>
> > +ConfigParser::parseConfigFile(File &file, PipelineHandler *pipe)
> > +{
> > +       std::vector<std::unique_ptr<VirtualCameraData>> configurations;
> > +
> > +       std::unique_ptr<YamlObject> cameras = YamlParser::parse(file);
> > +       if (!cameras) {
> > +               LOG(Virtual, Error) << "Failed to pass config file.";
> > +               return configurations;
> > +       }
> > +
> > +       if (!cameras->isDictionary()) {
> > +               LOG(Virtual, Error) << "Config file is not a dictionary at the top level.";
> > +               return configurations;
> > +       }
> > +
> > +       /* Look into the configuration of each camera */
> > +       for (const auto &[cameraId, cameraConfigData] : cameras->asDict()) {
> > +               std::unique_ptr<VirtualCameraData> data =
> > +                       parseCameraConfigData(cameraConfigData, pipe);
> > +               /* Parse configData to data */
> > +               if (!data) {
> > +                       /* Skip the camera if it has invalid config */
> > +                       LOG(Virtual, Error) << "Failed to parse config of the camera: "
> > +                                           << cameraId;
> > +                       continue;
> > +               }
> > +
> > +               data->config_.id = cameraId;
> > +               ControlInfoMap::Map controls;
> > +               /* todo: Check which resolution's frame rate to be reported */
> > +               controls[&controls::FrameDurationLimits] =
> > +                       ControlInfo(1000000 / data->config_.resolutions[0].frameRates[1],
> > +                                   1000000 / data->config_.resolutions[0].frameRates[0]);
> > +
> > +               std::vector<ControlValue> supportedFaceDetectModes{
> > +                       static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> > +               };
> > +               controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> > +
> > +               data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> > +               configurations.push_back(std::move(data));
> > +       }
> > +
> > +       return configurations;
> > +}
> > +
> > +std::unique_ptr<VirtualCameraData>
> > +ConfigParser::parseCameraConfigData(const YamlObject &cameraConfigData,
> > +                                   PipelineHandler *pipe)
> > +{
> > +       std::vector<VirtualCameraData::Resolution> resolutions;
> > +       if (parseSupportedFormats(cameraConfigData, &resolutions))
> > +               return nullptr;
> > +
> > +       std::unique_ptr<VirtualCameraData> data =
> > +               std::make_unique<VirtualCameraData>(pipe, resolutions);
> > +
> > +       if (parseFrameGenerator(cameraConfigData, data.get()))
> > +               return nullptr;
> > +
> > +       if (parseLocation(cameraConfigData, data.get()))
> > +               return nullptr;
> > +
> > +       if (parseModel(cameraConfigData, data.get()))
> > +               return nullptr;
> > +
> > +       return data;
> > +}
> > +
> > +int ConfigParser::parseSupportedFormats(const YamlObject &cameraConfigData,
> > +                                       std::vector<VirtualCameraData::Resolution> *resolutions)
> > +{
> > +       if (cameraConfigData.contains("supported_formats")) {
> > +               const YamlObject &supportedResolutions = cameraConfigData["supported_formats"];
> > +
> > +               for (const YamlObject &supportedResolution : supportedResolutions.asList()) {
> > +                       unsigned int width = supportedResolution["width"].get<unsigned int>(1920);
> > +                       unsigned int height = supportedResolution["height"].get<unsigned int>(1080);
> > +                       if (width == 0 || height == 0) {
> > +                               LOG(Virtual, Error) << "Invalid width or/and height";
> > +                               return -EINVAL;
> > +                       }
> > +                       if (width % 2 != 0) {
> > +                               LOG(Virtual, Error) << "Invalid width: width needs to be even";
> > +                               return -EINVAL;
> > +                       }
> > +
> > +                       std::vector<int64_t> frameRates;
> > +                       if (supportedResolution.contains("frame_rates")) {
> > +                               auto frameRatesList =
> > +                                       supportedResolution["frame_rates"].getList<int>();
> > +                               if (!frameRatesList || (frameRatesList->size() != 1 &&
> > +                                                       frameRatesList->size() != 2)) {
> > +                                       LOG(Virtual, Error) << "Invalid frame_rates: either one or two values";
> > +                                       return -EINVAL;
> > +                               }
> > +
> > +                               if (frameRatesList->size() == 2 &&
> > +                                   frameRatesList.value()[0] > frameRatesList.value()[1]) {
> > +                                       LOG(Virtual, Error) << "frame_rates's first value(lower bound)"
> > +                                                           << " is higher than the second value(upper bound)";
> > +                                       return -EINVAL;
> > +                               }
> > +                               /*
> > +                                 * Push the min and max framerates. A
> > +                                 * single rate is duplicated.
> > +                                 */
> > +                               frameRates.push_back(frameRatesList.value().front());
> > +                               frameRates.push_back(frameRatesList.value().back());
> > +                       } else {
> > +                               frameRates.push_back(30);
> > +                               frameRates.push_back(60);
> > +                       }
> > +
> > +                       resolutions->emplace_back(
> > +                               VirtualCameraData::Resolution{ Size{ width, height },
> > +                                                              frameRates });
> > +               }
> > +       } else {
> > +               resolutions->emplace_back(
> > +                       VirtualCameraData::Resolution{ Size{ 1920, 1080 },
> > +                                                      { 30, 60 } });
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +int ConfigParser::parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data)
> > +{
> > +       const std::string testPatternKey = "test_pattern";
> > +       const std::string framesKey = "frames";
> > +       if (cameraConfigData.contains(testPatternKey)) {
> > +               if (cameraConfigData.contains(framesKey)) {
> > +                       LOG(Virtual, Error) << "A camera should use either "
> > +                                           << testPatternKey << " or " << framesKey;
> > +                       return -EINVAL;
> > +               }
> > +
> > +               auto testPattern = cameraConfigData[testPatternKey].get<std::string>("");
> > +
> > +               if (testPattern == "bars") {
> > +                       data->config_.frame = TestPattern::ColorBars;
> > +               } else if (testPattern == "lines") {
> > +                       data->config_.frame = TestPattern::DiagonalLines;
> > +               } else {
> > +                       LOG(Virtual, Debug) << "Test pattern: " << testPattern
> > +                                           << " is not supported";
> > +                       return -EINVAL;
> > +               }
> > +
> > +               return 0;
> > +       }
> > +
> > +       const YamlObject &frames = cameraConfigData[framesKey];
> > +
> > +       /* When there is no frames provided in the config file, use color bar test pattern */
> > +       if (!frames) {
> > +               data->config_.frame = TestPattern::ColorBars;
> > +               return 0;
> > +       }
> > +
> > +       if (!frames.isDictionary()) {
> > +               LOG(Virtual, Error) << "'frames' is not a dictionary.";
> > +               return -EINVAL;
> > +       }
> > +
> > +       auto path = frames["path"].get<std::string>();
> > +
> > +       if (!path) {
> > +               LOG(Virtual, Error) << "Test pattern or path should be specified.";
> > +               return -EINVAL;
> > +       }
> > +
> > +       std::vector<std::filesystem::path> files;
> > +
> > +       switch (std::filesystem::symlink_status(*path).type()) {
> > +       case std::filesystem::file_type::regular:
> > +               files.push_back(*path);
> > +               break;
> > +
> > +       case std::filesystem::file_type::directory:
> > +               for (const auto &dentry : std::filesystem::directory_iterator{ *path }) {
> > +                       if (dentry.is_regular_file())
> > +                               files.push_back(dentry.path());
> > +               }
> > +
> > +               std::sort(files.begin(), files.end(), [](const auto &a, const auto &b) {
> > +                       return ::strverscmp(a.c_str(), b.c_str()) < 0;
> > +               });
> > +
> > +               if (files.empty()) {
> > +                       LOG(Virtual, Error) << "Directory has no files: " << *path;
> > +                       return -EINVAL;
> > +               }
> > +               break;
> > +
> > +       default:
> > +               LOG(Virtual, Error) << "Frame: " << *path << " is not supported";
> > +               return -EINVAL;
> > +       }
> > +
> > +       data->config_.frame = ImageFrames{ std::move(files) };
> > +
> > +       return 0;
> > +}
> > +
> > +int ConfigParser::parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data)
> > +{
> > +       std::string location = cameraConfigData["location"].get<std::string>("front");
> > +
> > +       /* Default value is properties::CameraLocationFront */
> > +       if (location == "front") {
> > +               data->properties_.set(properties::Location,
> > +                                     properties::CameraLocationFront);
> > +       } else if (location == "back") {
> > +               data->properties_.set(properties::Location,
> > +                                     properties::CameraLocationBack);
> > +       } else {
> > +               LOG(Virtual, Error) << "location: " << location
> > +                                   << " is not supported";
>
> What about external ?
>
> I think the control framework provides a map of string to id for the
> enum types in fact, so you can do something like:
>
>
> int ConfigParser::parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data)
> {
>         std::string location = cameraConfigData["location"].get<std::string>("front");
>
>         auto it = properties::LocationNameValueMap.find(location);
>         if (it == properties::LocationNameValueMap.end()) {
>                 LOG(Virtual, Error)
>                        << "location: " << location << " is not supported";
>
>                 return -EINVAL;
>         }
>
>         data->properties_.set(properties::Location, it->second);
>
>         return 0;
> }
>
> Which is probably more future proof too if we for some reason add any
> other locations.

Makes sense, although the value has the prefix "CameraLocationXXX".
Updated.

>
>
>
> > +               return -EINVAL;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +int ConfigParser::parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data)
> > +{
> > +       std::string model = cameraConfigData["model"].get<std::string>("Unknown");
> > +
> > +       data->properties_.set(properties::Model, model);
> > +
> > +       return 0;
> > +}
> > +
> > +} /* namespace libcamera */
> > diff --git a/src/libcamera/pipeline/virtual/config_parser.h b/src/libcamera/pipeline/virtual/config_parser.h
> > new file mode 100644
> > index 000000000..9abba62d0
> > --- /dev/null
> > +++ b/src/libcamera/pipeline/virtual/config_parser.h
> > @@ -0,0 +1,39 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2024, Google Inc.
> > + *
> > + * config_parser.h - Virtual cameras helper to parse config file
>
> Drop 'config_parser.h - ' from here.

Done

>
> > + */
> > +
> > +#pragma once
> > +
> > +#include <memory>
> > +#include <vector>
> > +
> > +#include <libcamera/base/file.h>
> > +
> > +#include "libcamera/internal/pipeline_handler.h"
> > +#include "libcamera/internal/yaml_parser.h"
> > +
> > +#include "virtual.h"
> > +
> > +namespace libcamera {
> > +
> > +class ConfigParser
> > +{
> > +public:
> > +       std::vector<std::unique_ptr<VirtualCameraData>>
> > +       parseConfigFile(File &file, PipelineHandler *pipe);
> > +
> > +private:
> > +       std::unique_ptr<VirtualCameraData>
> > +       parseCameraConfigData(const YamlObject &cameraConfigData, PipelineHandler *pipe);
> > +
> > +       int parseSupportedFormats(const YamlObject &cameraConfigData,
> > +                                 std::vector<VirtualCameraData::Resolution> *resolutions);
> > +       int parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data);
> > +       int parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data);
> > +       int parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data);
> > +};
> > +
> > +} /* namespace libcamera */
> > diff --git a/src/libcamera/pipeline/virtual/data/virtual.yaml b/src/libcamera/pipeline/virtual/data/virtual.yaml
> > new file mode 100644
> > index 000000000..6b73ddf2b
> > --- /dev/null
> > +++ b/src/libcamera/pipeline/virtual/data/virtual.yaml
> > @@ -0,0 +1,36 @@
> > +# SPDX-License-Identifier: CC0-1.0
> > +%YAML 1.1
> > +---
> > +"Virtual0":
> > +  supported_formats:
> > +  - width: 1920
> > +    height: 1080
> > +    frame_rates:
> > +    - 30
> > +    - 60
> > +  - width: 1680
> > +    height: 1050
> > +    frame_rates:
> > +    - 70
> > +    - 80
> > +  test_pattern: "lines"
> > +  location: "front"
> > +  model: "Virtual Video Device"
> > +"Virtual1":
> > +  supported_formats:
> > +  - width: 800
> > +    height: 600
> > +    frame_rates:
> > +    - 60
> > +  test_pattern: "bars"
> > +  location: "back"
> > +  model: "Virtual Video Device1"
> > +"Virtual2":
> > +  supported_formats:
> > +  - width: 400
> > +    height: 300
> > +  test_pattern: "lines"
> > +  location: "front"
> > +  model: "Virtual Video Device2"
> > +"Virtual3":
> > +  test_pattern: "bars"
> > diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.cpp b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> > index 04382beb7..36bdc20e5 100644
> > --- a/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> > +++ b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> > @@ -40,15 +40,7 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
> >          * For each file in the directory, load the image,
> >          * convert it to NV12, and store the pointer.
> >          */
> > -       for (unsigned int i = 0; i < imageFrames.number.value_or(1); i++) {
> > -               std::filesystem::path path;
> > -               if (!imageFrames.number)
> > -                       /* If the path is to an image */
> > -                       path = imageFrames.path;
> > -               else
> > -                       /* If the path is to a directory */
> > -                       path = imageFrames.path / (std::to_string(i) + ".jpg");
> > -
> > +       for (std::filesystem::path path : imageFrames.files) {
> >                 File file(path);
> >                 if (!file.open(File::OpenModeFlag::ReadOnly)) {
> >                         LOG(Virtual, Error) << "Failed to open image file " << file.fileName()
> > @@ -88,6 +80,8 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
> >                                         Size(width, height) });
> >         }
> >
> > +       ASSERT(!imageFrameGenerator->imageFrameDatas_.empty());
> > +
> >         return imageFrameGenerator;
> >  }
> >
> > @@ -104,7 +98,7 @@ void ImageFrameGenerator::configure(const Size &size)
> >         frameIndex_ = 0;
> >         parameter_ = 0;
> >
> > -       for (unsigned int i = 0; i < imageFrames_->number.value_or(1); i++) {
> > +       for (unsigned int i = 0; i < imageFrameDatas_.size(); i++) {
> >                 /* Scale the imageFrameDatas_ to scaledY and scaledUV */
> >                 unsigned int halfSizeWidth = (size.width + 1) / 2;
> >                 unsigned int halfSizeHeight = (size.height + 1) / 2;
> > @@ -139,7 +133,7 @@ int ImageFrameGenerator::generateFrame(const Size &size, const FrameBuffer *buff
> >         auto planes = mappedFrameBuffer.planes();
> >
> >         /* Loop only around the number of images available */
> > -       frameIndex_ %= imageFrames_->number.value_or(1);
> > +       frameIndex_ %= imageFrameDatas_.size();
> >
> >         /* Write the scaledY and scaledUV to the mapped frame buffer */
> >         libyuv::NV12Copy(scaledFrameDatas_[frameIndex_].Y.get(), size.width,
> > diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.h b/src/libcamera/pipeline/virtual/image_frame_generator.h
> > index a68094a66..8554d647d 100644
> > --- a/src/libcamera/pipeline/virtual/image_frame_generator.h
> > +++ b/src/libcamera/pipeline/virtual/image_frame_generator.h
> > @@ -10,9 +10,9 @@
> >
> >  #include <filesystem>
> >  #include <memory>
> > -#include <optional>
> >  #include <stdint.h>
> >  #include <sys/types.h>
> > +#include <vector>
> >
> >  #include "frame_generator.h"
> >
> > @@ -20,8 +20,7 @@ namespace libcamera {
> >
> >  /* Frame configuration provided by the config file */
> >  struct ImageFrames {
> > -       std::filesystem::path path;
> > -       std::optional<unsigned int> number;
> > +       std::vector<std::filesystem::path> files;
> >  };
> >
> >  class ImageFrameGenerator : public FrameGenerator
> > diff --git a/src/libcamera/pipeline/virtual/meson.build b/src/libcamera/pipeline/virtual/meson.build
> > index bb38c193c..4786fe2e0 100644
> > --- a/src/libcamera/pipeline/virtual/meson.build
> > +++ b/src/libcamera/pipeline/virtual/meson.build
> > @@ -1,6 +1,7 @@
> >  # SPDX-License-Identifier: CC0-1.0
> >
> >  libcamera_internal_sources += files([
> > +    'config_parser.cpp',
> >      'image_frame_generator.cpp',
> >      'test_pattern_generator.cpp',
> >      'virtual.cpp',
> > diff --git a/src/libcamera/pipeline/virtual/virtual.cpp b/src/libcamera/pipeline/virtual/virtual.cpp
> > index 1ad7417c7..cafd395c3 100644
> > --- a/src/libcamera/pipeline/virtual/virtual.cpp
> > +++ b/src/libcamera/pipeline/virtual/virtual.cpp
> > @@ -36,6 +36,9 @@
> >  #include "libcamera/internal/formats.h"
> >  #include "libcamera/internal/framebuffer.h"
> >  #include "libcamera/internal/pipeline_handler.h"
> > +#include "libcamera/internal/yaml_parser.h"
> > +
> > +#include "pipeline/virtual/config_parser.h"
> >
> >  namespace libcamera {
> >
> > @@ -54,6 +57,13 @@ uint64_t currentTimestamp()
> >
> >  } /* namespace */
> >
> > +template<class... Ts>
> > +struct overloaded : Ts... {
> > +       using Ts::operator()...;
> > +};
> > +template<class... Ts>
> > +overloaded(Ts...) -> overloaded<Ts...>;
> > +
> >  class VirtualCameraConfiguration : public CameraConfiguration
> >  {
> >  public:
> > @@ -95,7 +105,7 @@ private:
> >                 return static_cast<VirtualCameraData *>(camera->_d());
> >         }
> >
> > -       void initFrameGenerator(Camera *camera);
> > +       bool initFrameGenerator(Camera *camera);
> >
> >         DmaBufAllocator dmaBufAllocator_;
> >
> > @@ -104,15 +114,19 @@ private:
> >
> >  VirtualCameraData::VirtualCameraData(PipelineHandler *pipe,
> >                                      const std::vector<Resolution> &supportedResolutions)
> > -       : Camera::Private(pipe), supportedResolutions_(supportedResolutions)
> > +       : Camera::Private(pipe)
> >  {
> > -       for (const auto &resolution : supportedResolutions_) {
> > -               if (minResolutionSize_.isNull() || minResolutionSize_ > resolution.size)
> > -                       minResolutionSize_ = resolution.size;
> > +       config_.resolutions = supportedResolutions;
> > +       for (const auto &resolution : config_.resolutions) {
> > +               if (config_.minResolutionSize.isNull() || config_.minResolutionSize > resolution.size)
> > +                       config_.minResolutionSize = resolution.size;
> >
> > -               maxResolutionSize_ = std::max(maxResolutionSize_, resolution.size);
> > +               config_.maxResolutionSize = std::max(config_.maxResolutionSize, resolution.size);
> >         }
> >
> > +       properties_.set(properties::PixelArrayActiveAreas,
> > +                       { Rectangle(config_.maxResolutionSize) });
> > +
> >         /* \todo Support multiple streams and pass multi_stream_test */
> >         streamConfigs_.resize(kMaxStream);
> >  }
> > @@ -140,7 +154,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
> >         for (StreamConfiguration &cfg : config_) {
> >                 bool adjusted = false;
> >                 bool found = false;
> > -               for (const auto &resolution : data_->supportedResolutions_) {
> > +               for (const auto &resolution : data_->config_.resolutions) {
> >                         if (resolution.size.width == cfg.size.width &&
> >                             resolution.size.height == cfg.size.height) {
> >                                 found = true;
> > @@ -155,7 +169,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
> >                          * Defining the default logic in PipelineHandler to
> >                          * find the closest resolution would be nice.
> >                          */
> > -                       cfg.size = data_->maxResolutionSize_;
> > +                       cfg.size = data_->config_.maxResolutionSize;
> >                         status = Adjusted;
> >                         adjusted = true;
> >                 }
> > @@ -224,12 +238,12 @@ PipelineHandlerVirtual::generateConfiguration(Camera *camera,
> >
> >                 std::map<PixelFormat, std::vector<SizeRange>> streamFormats;
> >                 PixelFormat pixelFormat = formats::NV12;
> > -               streamFormats[pixelFormat] = { { data->minResolutionSize_,
> > -                                                data->maxResolutionSize_ } };
> > +               streamFormats[pixelFormat] = { { data->config_.minResolutionSize,
> > +                                                data->config_.maxResolutionSize } };
> >                 StreamFormats formats(streamFormats);
> >                 StreamConfiguration cfg(formats);
> >                 cfg.pixelFormat = pixelFormat;
> > -               cfg.size = data->maxResolutionSize_;
> > +               cfg.size = data->config_.maxResolutionSize;
> >                 cfg.bufferCount = VirtualCameraConfiguration::kBufferCount;
> >
> >                 config->addConfiguration(cfg);
> > @@ -246,6 +260,7 @@ int PipelineHandlerVirtual::configure(Camera *camera,
> >         VirtualCameraData *data = cameraData(camera);
> >         for (auto [i, c] : utils::enumerate(*config)) {
> >                 c.setStream(&data->streamConfigs_[i].stream);
> > +               /* Start reading the images/generating test patterns */
> >                 data->streamConfigs_[i].frameGenerator->configure(c.size);
> >         }
> >
> > @@ -315,56 +330,67 @@ bool PipelineHandlerVirtual::match([[maybe_unused]] DeviceEnumerator *enumerator
> >
> >         created_ = true;
> >
> > -       /* \todo Add virtual cameras according to a config file. */
> > -
> > -       std::vector<VirtualCameraData::Resolution> supportedResolutions;
> > -       supportedResolutions.resize(2);
> > -       supportedResolutions[0] = { .size = Size(1920, 1080), .frameRates = { 30 } };
> > -       supportedResolutions[1] = { .size = Size(1280, 720), .frameRates = { 30 } };
> > -
> > -       std::unique_ptr<VirtualCameraData> data =
> > -               std::make_unique<VirtualCameraData>(this, supportedResolutions);
> > -
> > -       data->properties_.set(properties::Location, properties::CameraLocationFront);
> > -       data->properties_.set(properties::Model, "Virtual Video Device");
> > -       data->properties_.set(properties::PixelArrayActiveAreas, { Rectangle(Size(1920, 1080)) });
> > -
> > -       /* \todo Set FrameDurationLimits based on config. */
> > -       ControlInfoMap::Map controls;
> > -       int64_t min_frame_duration = 33333, max_frame_duration = 33333;
> > -       controls[&controls::FrameDurationLimits] = ControlInfo(min_frame_duration, max_frame_duration);
> > -       std::vector<ControlValue> supportedFaceDetectModes{
> > -               static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> > -       };
> > -       controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> > -       data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> > -
> > -       /* Create and register the camera. */
> > -       std::set<Stream *> streams;
> > -       for (auto &streamConfig : data->streamConfigs_)
> > -               streams.insert(&streamConfig.stream);
> > +       File file(configurationFile("virtual", "virtual.yaml"));
>
> This tells me that the sample virtual.yaml file should probably be
> installed in the libcamera data path...

Yes, updated the README.md.


>
> This version doesn't currently apply cleanly to master, but I did have
> an branch with it on - and it rebased easily.

Rebased on tot in the next version.


>
> But it needs a new version posting at least to solve the SoB issues and
> so with the above tackled you can add
>
> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
>
>
> > +       bool isOpen = file.open(File::OpenModeFlag::ReadOnly);
> > +       if (!isOpen) {
> > +               LOG(Virtual, Error) << "Failed to open config file: " << file.fileName();
> > +               return false;
> > +       }
> >
> > -       const std::string id = "Virtual0";
> > -       std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> > +       ConfigParser parser;
> > +       auto configData = parser.parseConfigFile(file, this);
> > +       if (configData.size() == 0) {
> > +               LOG(Virtual, Error) << "Failed to parse any cameras from the config file: "
> > +                                   << file.fileName();
> > +               return false;
> > +       }
> >
> > -       initFrameGenerator(camera.get());
> > +       /* Configure and register cameras with configData */
> > +       for (auto &data : configData) {
> > +               std::set<Stream *> streams;
> > +               for (auto &streamConfig : data->streamConfigs_)
> > +                       streams.insert(&streamConfig.stream);
> > +               std::string id = data->config_.id;
> > +               std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> > +
> > +               if (!initFrameGenerator(camera.get())) {
> > +                       LOG(Virtual, Error) << "Failed to initialize frame "
> > +                                           << "generator for camera: " << id;
> > +                       continue;
> > +               }
> >
> > -       registerCamera(std::move(camera));
> > +               registerCamera(std::move(camera));
> > +       }
> >
> >         resetCreated_ = true;
> >
> >         return true;
> >  }
> >
> > -void PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
> > +bool PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
> >  {
> >         auto data = cameraData(camera);
> > -       for (auto &streamConfig : data->streamConfigs_) {
> > -               if (data->testPattern_ == TestPattern::DiagonalLines)
> > -                       streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> > -               else
> > -                       streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> > -       }
> > +       auto &frame = data->config_.frame;
> > +       std::visit(overloaded{
> > +                          [&](TestPattern &testPattern) {
> > +                                  for (auto &streamConfig : data->streamConfigs_) {
> > +                                          if (testPattern == TestPattern::DiagonalLines)
> > +                                                  streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> > +                                          else
> > +                                                  streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> > +                                  }
> > +                          },
> > +                          [&](ImageFrames &imageFrames) {
> > +                                  for (auto &streamConfig : data->streamConfigs_)
> > +                                          streamConfig.frameGenerator = ImageFrameGenerator::create(imageFrames);
> > +                          } },
> > +                  frame);
> > +
> > +       for (auto &streamConfig : data->streamConfigs_)
> > +               if (!streamConfig.frameGenerator)
> > +                       return false;
> > +
> > +       return true;
> >  }
> >
> >  REGISTER_PIPELINE_HANDLER(PipelineHandlerVirtual, "virtual")
> > diff --git a/src/libcamera/pipeline/virtual/virtual.h b/src/libcamera/pipeline/virtual/virtual.h
> > index 0b15f8d9c..8c4d6ae64 100644
> > --- a/src/libcamera/pipeline/virtual/virtual.h
> > +++ b/src/libcamera/pipeline/virtual/virtual.h
> > @@ -7,6 +7,8 @@
> >
> >  #pragma once
> >
> > +#include <string>
> > +#include <variant>
> >  #include <vector>
> >
> >  #include <libcamera/geometry.h>
> > @@ -15,10 +17,14 @@
> >  #include "libcamera/internal/camera.h"
> >  #include "libcamera/internal/pipeline_handler.h"
> >
> > +#include "frame_generator.h"
> > +#include "image_frame_generator.h"
> >  #include "test_pattern_generator.h"
> >
> >  namespace libcamera {
> >
> > +using VirtualFrame = std::variant<TestPattern, ImageFrames>;
> > +
> >  class VirtualCameraData : public Camera::Private
> >  {
> >  public:
> > @@ -26,23 +32,28 @@ public:
> >
> >         struct Resolution {
> >                 Size size;
> > -               std::vector<int> frameRates;
> > +               std::vector<int64_t> frameRates;
> >         };
> >         struct StreamConfig {
> >                 Stream stream;
> >                 std::unique_ptr<FrameGenerator> frameGenerator;
> >         };
> > +       /* The config file is parsed to the Configuration struct */
> > +       struct Configuration {
> > +               std::string id;
> > +               std::vector<Resolution> resolutions;
> > +               VirtualFrame frame;
> > +
> > +               Size maxResolutionSize;
> > +               Size minResolutionSize;
> > +       };
> >
> >         VirtualCameraData(PipelineHandler *pipe,
> >                           const std::vector<Resolution> &supportedResolutions);
> >
> >         ~VirtualCameraData() = default;
> >
> > -       TestPattern testPattern_ = TestPattern::ColorBars;
> > -
> > -       const std::vector<Resolution> supportedResolutions_;
> > -       Size maxResolutionSize_;
> > -       Size minResolutionSize_;
> > +       Configuration config_;
> >
> >         std::vector<StreamConfig> streamConfigs_;
> >  };
> > --
> > 2.47.0.rc0.187.ge670bccf7e-goog
> >

Quoting Cheng-Hao Yang (2024-10-22 08:46:05)
> Hi Kieran,
> 
> On Tue, Oct 22, 2024 at 7:31 AM Kieran Bingham
> <kieran.bingham@ideasonboard.com> wrote:
> >
> > Quoting Harvey Yang (2024-10-04 10:59:19)
> > > This patch introduces the configuration file for Virtual Pipeline
> > > Handler. The config file is written in yaml, and the format is
> > > documented in `README.md`.
> > >
> > > The config file will define the camera with IDs, supported formats and
> > > image sources, etc. In the default config file, only Test Patterns are
> > > used. Developers can use real images loading if desired.
> > >
> > > Signed-off-by: Konami Shu <konamiz@google.com>
> > > Co-developed-by: Harvey Yang <chenghaoyang@chromium.org>
> > > Co-developed-by: Yunke Cao <yunkec@chromium.org>
> > > Co-developed-by: Tomasz Figa <tfiga@chromium.org>
> >
> > I think we determined Co-developed-by: need SoBs.
> 
> Yes, updated. I didn't upload a new version to avoid the spam.

Ack,

> 
> >
> > Checkstyle reports:
> >
> > -----------------------------------------------------------------------------------------------------------------
> > 83f896b4afa8e5e7a4029d1e07bcb5dfe8cc5fb2 libcamera: virtual: Read config and register cameras based on the config
> > -----------------------------------------------------------------------------------------------------------------
> > No 'Signed-off-by' trailer matching author 'Harvey Yang <chenghaoyang@chromium.org>', see Documentation/contributing.rst
> > ---
> > 1 potential issue detected, please review
> >
> > And that will apply to all the above.
> 
> Done.
> 

Thanks

> >
> >
> > > ---
> > >  src/libcamera/pipeline/virtual/README.md      |  65 +++++
> > >  .../pipeline/virtual/config_parser.cpp        | 263 ++++++++++++++++++
> > >  .../pipeline/virtual/config_parser.h          |  39 +++
> > >  .../pipeline/virtual/data/virtual.yaml        |  36 +++
> > >  .../virtual/image_frame_generator.cpp         |  16 +-
> > >  .../pipeline/virtual/image_frame_generator.h  |   5 +-
> > >  src/libcamera/pipeline/virtual/meson.build    |   1 +
> > >  src/libcamera/pipeline/virtual/virtual.cpp    | 126 +++++----
> > >  src/libcamera/pipeline/virtual/virtual.h      |  23 +-
> > >  9 files changed, 504 insertions(+), 70 deletions(-)
> > >  create mode 100644 src/libcamera/pipeline/virtual/README.md
> > >  create mode 100644 src/libcamera/pipeline/virtual/config_parser.cpp
> > >  create mode 100644 src/libcamera/pipeline/virtual/config_parser.h
> > >  create mode 100644 src/libcamera/pipeline/virtual/data/virtual.yaml
> > >
> > > diff --git a/src/libcamera/pipeline/virtual/README.md b/src/libcamera/pipeline/virtual/README.md
> > > new file mode 100644
> > > index 000000000..5801e79b5
> > > --- /dev/null
> > > +++ b/src/libcamera/pipeline/virtual/README.md
> > > @@ -0,0 +1,65 @@
> > > +# Virtual Pipeline Handler
> > > +
> > > +Virtual pipeline handler emulates fake external camera(s) on ChromeOS for testing.
> >
> > It's not only on ChromeOS right ? It's just a virtual camera for any
> > platform.
> 
> Right, removed.
> 
> >
> >
> >
> > > +
> > > +## Parse config file and register cameras
> > > +
> > > +- The config file is located at `src/libcamera/pipeline/virtual/data/virtual.yaml`
> >
> > I'm sure I mentioned this before - but this is the source location.
> > While I preume the users would have to configure their 'installed'
> > location. So this should probably reference the fact it would be
> > installed in ...
> >
> > Err - where does it get installed ? What happens if libcamera is
> > installed and tries to use the virtual pipeline handler here ?
> >
> > I don't see any reference in a meson file that installes
> > data/virtual.yaml ?
> >
> >
> > Later on virtual.yaml is mentioned as a sample, while up here it's
> > specified as '"The" config file'. ?
> >
> > Maybe this should say "A sample config file is located at ..."
> 
> Yes, it depends on if libcamera is installed. Updated and added
> the installed path:
> `shar/libcamera/pipeline/virtual/virtual.yaml`.

I think that's the default - but it's probably worth mentioning in a way
that says it's will be installed in the 'datadir' which has a default
location of 'share/libcamera/...' as this is configurable when doing the
meson setup stage.

> > > +
> > > +### Config File Format
> > > +The config file contains the information about cameras' properties to register.
> > > +The config file should be a yaml file with dictionary of the cameraIds
> > > +associated with their properties as top level. The default value will be applied
> > > +when any property is empty.
> > > +
> > > +Each camera block is a dictionary, containing the following keys:
> > > +- `supported_formats` (list of `VirtualCameraData::Resolution`, optional) :
> > > +  List of supported resolution and frame rates of the emulated camera
> > > +    - `width` (`unsigned int`, default=1920): Width of the window resolution.
> > > +      This needs to be even.
> > > +    - `height` (`unsigned int`, default=1080): Height of the window resolution.
> > > +    - `frame_rates` (list of `int`, default=`[30,60]` ): Range of the frame
> > > +      rate (per second). If the list contains one value, it's the lower bound
> > > +      and the upper bound. If the list contains two values, the first is the
> > > +      lower bound and the second is the upper bound. No other number of values
> > > +      is allowed.
> > > +- `test_pattern` (`string`): Which test pattern to use as frames. The options
> > > +  are "bars", "lines". Cannot be set with `frames`.
> > > +- `frames` (dictionary):
> > > +  - `path` (`string`): Path to an image, or path to a directory of a series of
> > > +    images. Cannot be set with `test_pattern`.
> > > +    - The test patterns are "bars" which means color bars, and "lines" which
> > > +      means diagonal lines.
> >
> > Does this bullet point belong to the 'test_pattern' section above rather
> > than frames ?
> 
> Right, thanks! Updated.
> 
> >
> > > +    - The path to an image has ".jpg" extension.
> > > +    - The path to a directory ends with "/". The name of the images in the
> > > +      directory are "{n}.jpg" with {n} is the sequence of images starting with 0.
> > > +- `location` (`string`, default="front"): The location of the camera. Support
> > > +  "front" and "back". This is displayed in qcam camera selection window but
> >
> > I don't think it's relevant to mention 'qcam' here. Setting the location
> > defines the location property of the camera which is exposed by the
> > camera in /any/ application. Not just qcam.
> 
> Right, removed this and the one in `model`.

Aha, I missed that one ;-)

> 
> >
> >
> > > +  this does not change the output.
> > > +- `model` (`string`, default="Unknown"): The model name of the camera.
> > > +  This is displayed in qcam camera selection window but this does not change the output.
> > > +
> > > +Check `data/virtual.yaml` as the sample config file.
> > > +
> > > +### Implementation
> > > +
> > > +`Parser` class provides methods to parse the config file to register cameras
> > > +in Virtual Pipeline Handler. `parseConfigFile()` is exposed to use in
> > > +Virtual Pipeline Handler.
> > > +
> > > +This is the procedure of the Parser class:
> > > +1. `parseConfigFile()` parses the config file to `YamlObject` using `YamlParser::parse()`.
> > > +    - Parse the top level of config file which are the camera ids and look into
> > > +      each camera properties.
> > > +2. For each camera, `parseCameraConfigData()` returns a camera with the configuration.
> > > +    - The methods in the next step fill the data with the pointer to the Camera object.
> > > +    - If the config file contains invalid configuration, this method returns
> > > +      nullptr. The camera will be skipped.
> > > +3. Parse each property and register the data.
> > > +    - `parseSupportedFormats()`: Parses `supported_formats` in the config, which
> > > +      contains resolutions and frame rates.
> > > +    - `parseFrameGenerator()`: Parses `test_pattern` or `frames` in the config.
> > > +    - `parseLocation()`: Parses `location` in the config.
> > > +    - `parseModel()`: Parses `model` in the config.
> > > +4. Back to `parseConfigFile()` and append the camera configuration.
> > > +5. Returns a list of camera configurations.
> > > diff --git a/src/libcamera/pipeline/virtual/config_parser.cpp b/src/libcamera/pipeline/virtual/config_parser.cpp
> > > new file mode 100644
> > > index 000000000..467dde485
> > > --- /dev/null
> > > +++ b/src/libcamera/pipeline/virtual/config_parser.cpp
> > > @@ -0,0 +1,263 @@
> > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > +/*
> > > + * Copyright (C) 2024, Google Inc.
> > > + *
> > > + * config_parser.cpp - Virtual cameras helper to parse config file
> >
> > Drop 'config_parser.cpp - ' We stopped putting file names in their own
> > files as they bitrot and don't add value
> 
> Done
> 
> >
> > > + */
> > > +
> > > +#include "config_parser.h"
> > > +
> > > +#include <string.h>
> > > +#include <utility>
> > > +
> > > +#include <libcamera/base/log.h>
> > > +
> > > +#include <libcamera/control_ids.h>
> > > +#include <libcamera/property_ids.h>
> > > +
> > > +#include "libcamera/internal/pipeline_handler.h"
> > > +#include "libcamera/internal/yaml_parser.h"
> > > +
> > > +#include "virtual.h"
> > > +
> > > +namespace libcamera {
> > > +
> > > +LOG_DECLARE_CATEGORY(Virtual)
> > > +
> > > +std::vector<std::unique_ptr<VirtualCameraData>>
> > > +ConfigParser::parseConfigFile(File &file, PipelineHandler *pipe)
> > > +{
> > > +       std::vector<std::unique_ptr<VirtualCameraData>> configurations;
> > > +
> > > +       std::unique_ptr<YamlObject> cameras = YamlParser::parse(file);
> > > +       if (!cameras) {
> > > +               LOG(Virtual, Error) << "Failed to pass config file.";
> > > +               return configurations;
> > > +       }
> > > +
> > > +       if (!cameras->isDictionary()) {
> > > +               LOG(Virtual, Error) << "Config file is not a dictionary at the top level.";
> > > +               return configurations;
> > > +       }
> > > +
> > > +       /* Look into the configuration of each camera */
> > > +       for (const auto &[cameraId, cameraConfigData] : cameras->asDict()) {
> > > +               std::unique_ptr<VirtualCameraData> data =
> > > +                       parseCameraConfigData(cameraConfigData, pipe);
> > > +               /* Parse configData to data */
> > > +               if (!data) {
> > > +                       /* Skip the camera if it has invalid config */
> > > +                       LOG(Virtual, Error) << "Failed to parse config of the camera: "
> > > +                                           << cameraId;
> > > +                       continue;
> > > +               }
> > > +
> > > +               data->config_.id = cameraId;
> > > +               ControlInfoMap::Map controls;
> > > +               /* todo: Check which resolution's frame rate to be reported */
> > > +               controls[&controls::FrameDurationLimits] =
> > > +                       ControlInfo(1000000 / data->config_.resolutions[0].frameRates[1],
> > > +                                   1000000 / data->config_.resolutions[0].frameRates[0]);
> > > +
> > > +               std::vector<ControlValue> supportedFaceDetectModes{
> > > +                       static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> > > +               };
> > > +               controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> > > +
> > > +               data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> > > +               configurations.push_back(std::move(data));
> > > +       }
> > > +
> > > +       return configurations;
> > > +}
> > > +
> > > +std::unique_ptr<VirtualCameraData>
> > > +ConfigParser::parseCameraConfigData(const YamlObject &cameraConfigData,
> > > +                                   PipelineHandler *pipe)
> > > +{
> > > +       std::vector<VirtualCameraData::Resolution> resolutions;
> > > +       if (parseSupportedFormats(cameraConfigData, &resolutions))
> > > +               return nullptr;
> > > +
> > > +       std::unique_ptr<VirtualCameraData> data =
> > > +               std::make_unique<VirtualCameraData>(pipe, resolutions);
> > > +
> > > +       if (parseFrameGenerator(cameraConfigData, data.get()))
> > > +               return nullptr;
> > > +
> > > +       if (parseLocation(cameraConfigData, data.get()))
> > > +               return nullptr;
> > > +
> > > +       if (parseModel(cameraConfigData, data.get()))
> > > +               return nullptr;
> > > +
> > > +       return data;
> > > +}
> > > +
> > > +int ConfigParser::parseSupportedFormats(const YamlObject &cameraConfigData,
> > > +                                       std::vector<VirtualCameraData::Resolution> *resolutions)
> > > +{
> > > +       if (cameraConfigData.contains("supported_formats")) {
> > > +               const YamlObject &supportedResolutions = cameraConfigData["supported_formats"];
> > > +
> > > +               for (const YamlObject &supportedResolution : supportedResolutions.asList()) {
> > > +                       unsigned int width = supportedResolution["width"].get<unsigned int>(1920);
> > > +                       unsigned int height = supportedResolution["height"].get<unsigned int>(1080);
> > > +                       if (width == 0 || height == 0) {
> > > +                               LOG(Virtual, Error) << "Invalid width or/and height";
> > > +                               return -EINVAL;
> > > +                       }
> > > +                       if (width % 2 != 0) {
> > > +                               LOG(Virtual, Error) << "Invalid width: width needs to be even";
> > > +                               return -EINVAL;
> > > +                       }
> > > +
> > > +                       std::vector<int64_t> frameRates;
> > > +                       if (supportedResolution.contains("frame_rates")) {
> > > +                               auto frameRatesList =
> > > +                                       supportedResolution["frame_rates"].getList<int>();
> > > +                               if (!frameRatesList || (frameRatesList->size() != 1 &&
> > > +                                                       frameRatesList->size() != 2)) {
> > > +                                       LOG(Virtual, Error) << "Invalid frame_rates: either one or two values";
> > > +                                       return -EINVAL;
> > > +                               }
> > > +
> > > +                               if (frameRatesList->size() == 2 &&
> > > +                                   frameRatesList.value()[0] > frameRatesList.value()[1]) {
> > > +                                       LOG(Virtual, Error) << "frame_rates's first value(lower bound)"
> > > +                                                           << " is higher than the second value(upper bound)";
> > > +                                       return -EINVAL;
> > > +                               }
> > > +                               /*
> > > +                                 * Push the min and max framerates. A
> > > +                                 * single rate is duplicated.
> > > +                                 */
> > > +                               frameRates.push_back(frameRatesList.value().front());
> > > +                               frameRates.push_back(frameRatesList.value().back());
> > > +                       } else {
> > > +                               frameRates.push_back(30);
> > > +                               frameRates.push_back(60);
> > > +                       }
> > > +
> > > +                       resolutions->emplace_back(
> > > +                               VirtualCameraData::Resolution{ Size{ width, height },
> > > +                                                              frameRates });
> > > +               }
> > > +       } else {
> > > +               resolutions->emplace_back(
> > > +                       VirtualCameraData::Resolution{ Size{ 1920, 1080 },
> > > +                                                      { 30, 60 } });
> > > +       }
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +int ConfigParser::parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data)
> > > +{
> > > +       const std::string testPatternKey = "test_pattern";
> > > +       const std::string framesKey = "frames";
> > > +       if (cameraConfigData.contains(testPatternKey)) {
> > > +               if (cameraConfigData.contains(framesKey)) {
> > > +                       LOG(Virtual, Error) << "A camera should use either "
> > > +                                           << testPatternKey << " or " << framesKey;
> > > +                       return -EINVAL;
> > > +               }
> > > +
> > > +               auto testPattern = cameraConfigData[testPatternKey].get<std::string>("");
> > > +
> > > +               if (testPattern == "bars") {
> > > +                       data->config_.frame = TestPattern::ColorBars;
> > > +               } else if (testPattern == "lines") {
> > > +                       data->config_.frame = TestPattern::DiagonalLines;
> > > +               } else {
> > > +                       LOG(Virtual, Debug) << "Test pattern: " << testPattern
> > > +                                           << " is not supported";
> > > +                       return -EINVAL;
> > > +               }
> > > +
> > > +               return 0;
> > > +       }
> > > +
> > > +       const YamlObject &frames = cameraConfigData[framesKey];
> > > +
> > > +       /* When there is no frames provided in the config file, use color bar test pattern */
> > > +       if (!frames) {
> > > +               data->config_.frame = TestPattern::ColorBars;
> > > +               return 0;
> > > +       }
> > > +
> > > +       if (!frames.isDictionary()) {
> > > +               LOG(Virtual, Error) << "'frames' is not a dictionary.";
> > > +               return -EINVAL;
> > > +       }
> > > +
> > > +       auto path = frames["path"].get<std::string>();
> > > +
> > > +       if (!path) {
> > > +               LOG(Virtual, Error) << "Test pattern or path should be specified.";
> > > +               return -EINVAL;
> > > +       }
> > > +
> > > +       std::vector<std::filesystem::path> files;
> > > +
> > > +       switch (std::filesystem::symlink_status(*path).type()) {
> > > +       case std::filesystem::file_type::regular:
> > > +               files.push_back(*path);
> > > +               break;
> > > +
> > > +       case std::filesystem::file_type::directory:
> > > +               for (const auto &dentry : std::filesystem::directory_iterator{ *path }) {
> > > +                       if (dentry.is_regular_file())
> > > +                               files.push_back(dentry.path());
> > > +               }
> > > +
> > > +               std::sort(files.begin(), files.end(), [](const auto &a, const auto &b) {
> > > +                       return ::strverscmp(a.c_str(), b.c_str()) < 0;
> > > +               });
> > > +
> > > +               if (files.empty()) {
> > > +                       LOG(Virtual, Error) << "Directory has no files: " << *path;
> > > +                       return -EINVAL;
> > > +               }
> > > +               break;
> > > +
> > > +       default:
> > > +               LOG(Virtual, Error) << "Frame: " << *path << " is not supported";
> > > +               return -EINVAL;
> > > +       }
> > > +
> > > +       data->config_.frame = ImageFrames{ std::move(files) };
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +int ConfigParser::parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data)
> > > +{
> > > +       std::string location = cameraConfigData["location"].get<std::string>("front");
> > > +
> > > +       /* Default value is properties::CameraLocationFront */
> > > +       if (location == "front") {
> > > +               data->properties_.set(properties::Location,
> > > +                                     properties::CameraLocationFront);
> > > +       } else if (location == "back") {
> > > +               data->properties_.set(properties::Location,
> > > +                                     properties::CameraLocationBack);
> > > +       } else {
> > > +               LOG(Virtual, Error) << "location: " << location
> > > +                                   << " is not supported";
> >
> > What about external ?
> >
> > I think the control framework provides a map of string to id for the
> > enum types in fact, so you can do something like:
> >
> >
> > int ConfigParser::parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data)
> > {
> >         std::string location = cameraConfigData["location"].get<std::string>("front");
> >
> >         auto it = properties::LocationNameValueMap.find(location);
> >         if (it == properties::LocationNameValueMap.end()) {
> >                 LOG(Virtual, Error)
> >                        << "location: " << location << " is not supported";
> >
> >                 return -EINVAL;
> >         }
> >
> >         data->properties_.set(properties::Location, it->second);
> >
> >         return 0;
> > }
> >
> > Which is probably more future proof too if we for some reason add any
> > other locations.
> 
> Makes sense, although the value has the prefix "CameraLocationXXX".
> Updated.


The enum values have CameraLocation indeed- but they are stored in the
LocationEnum because they are associated with the Location property
which has an associated array and map to convert between integer and
ControlValues:

See $(BUILDDIR)/include/libcamera/property_ids.h

enum LocationEnum {
        CameraLocationFront = 0,
        CameraLocationBack = 1,
        CameraLocationExternal = 2,
};
extern const std::array<const ControlValue, 3> LocationValues;
extern const std::map<std::string, int32_t> LocationNameValueMap;
extern const Control<int32_t> Location;

which is autogenerated.


> 
> >
> >
> >
> > > +               return -EINVAL;
> > > +       }
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +int ConfigParser::parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data)
> > > +{
> > > +       std::string model = cameraConfigData["model"].get<std::string>("Unknown");
> > > +
> > > +       data->properties_.set(properties::Model, model);
> > > +
> > > +       return 0;
> > > +}
> > > +
> > > +} /* namespace libcamera */
> > > diff --git a/src/libcamera/pipeline/virtual/config_parser.h b/src/libcamera/pipeline/virtual/config_parser.h
> > > new file mode 100644
> > > index 000000000..9abba62d0
> > > --- /dev/null
> > > +++ b/src/libcamera/pipeline/virtual/config_parser.h
> > > @@ -0,0 +1,39 @@
> > > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > > +/*
> > > + * Copyright (C) 2024, Google Inc.
> > > + *
> > > + * config_parser.h - Virtual cameras helper to parse config file
> >
> > Drop 'config_parser.h - ' from here.
> 
> Done
> 
> >
> > > + */
> > > +
> > > +#pragma once
> > > +
> > > +#include <memory>
> > > +#include <vector>
> > > +
> > > +#include <libcamera/base/file.h>
> > > +
> > > +#include "libcamera/internal/pipeline_handler.h"
> > > +#include "libcamera/internal/yaml_parser.h"
> > > +
> > > +#include "virtual.h"
> > > +
> > > +namespace libcamera {
> > > +
> > > +class ConfigParser
> > > +{
> > > +public:
> > > +       std::vector<std::unique_ptr<VirtualCameraData>>
> > > +       parseConfigFile(File &file, PipelineHandler *pipe);
> > > +
> > > +private:
> > > +       std::unique_ptr<VirtualCameraData>
> > > +       parseCameraConfigData(const YamlObject &cameraConfigData, PipelineHandler *pipe);
> > > +
> > > +       int parseSupportedFormats(const YamlObject &cameraConfigData,
> > > +                                 std::vector<VirtualCameraData::Resolution> *resolutions);
> > > +       int parseFrameGenerator(const YamlObject &cameraConfigData, VirtualCameraData *data);
> > > +       int parseLocation(const YamlObject &cameraConfigData, VirtualCameraData *data);
> > > +       int parseModel(const YamlObject &cameraConfigData, VirtualCameraData *data);
> > > +};
> > > +
> > > +} /* namespace libcamera */
> > > diff --git a/src/libcamera/pipeline/virtual/data/virtual.yaml b/src/libcamera/pipeline/virtual/data/virtual.yaml
> > > new file mode 100644
> > > index 000000000..6b73ddf2b
> > > --- /dev/null
> > > +++ b/src/libcamera/pipeline/virtual/data/virtual.yaml
> > > @@ -0,0 +1,36 @@
> > > +# SPDX-License-Identifier: CC0-1.0
> > > +%YAML 1.1
> > > +---
> > > +"Virtual0":
> > > +  supported_formats:
> > > +  - width: 1920
> > > +    height: 1080
> > > +    frame_rates:
> > > +    - 30
> > > +    - 60
> > > +  - width: 1680
> > > +    height: 1050
> > > +    frame_rates:
> > > +    - 70
> > > +    - 80
> > > +  test_pattern: "lines"
> > > +  location: "front"
> > > +  model: "Virtual Video Device"
> > > +"Virtual1":
> > > +  supported_formats:
> > > +  - width: 800
> > > +    height: 600
> > > +    frame_rates:
> > > +    - 60
> > > +  test_pattern: "bars"
> > > +  location: "back"
> > > +  model: "Virtual Video Device1"
> > > +"Virtual2":
> > > +  supported_formats:
> > > +  - width: 400
> > > +    height: 300
> > > +  test_pattern: "lines"
> > > +  location: "front"
> > > +  model: "Virtual Video Device2"
> > > +"Virtual3":
> > > +  test_pattern: "bars"
> > > diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.cpp b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> > > index 04382beb7..36bdc20e5 100644
> > > --- a/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> > > +++ b/src/libcamera/pipeline/virtual/image_frame_generator.cpp
> > > @@ -40,15 +40,7 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
> > >          * For each file in the directory, load the image,
> > >          * convert it to NV12, and store the pointer.
> > >          */
> > > -       for (unsigned int i = 0; i < imageFrames.number.value_or(1); i++) {
> > > -               std::filesystem::path path;
> > > -               if (!imageFrames.number)
> > > -                       /* If the path is to an image */
> > > -                       path = imageFrames.path;
> > > -               else
> > > -                       /* If the path is to a directory */
> > > -                       path = imageFrames.path / (std::to_string(i) + ".jpg");
> > > -
> > > +       for (std::filesystem::path path : imageFrames.files) {
> > >                 File file(path);
> > >                 if (!file.open(File::OpenModeFlag::ReadOnly)) {
> > >                         LOG(Virtual, Error) << "Failed to open image file " << file.fileName()
> > > @@ -88,6 +80,8 @@ ImageFrameGenerator::create(ImageFrames &imageFrames)
> > >                                         Size(width, height) });
> > >         }
> > >
> > > +       ASSERT(!imageFrameGenerator->imageFrameDatas_.empty());
> > > +
> > >         return imageFrameGenerator;
> > >  }
> > >
> > > @@ -104,7 +98,7 @@ void ImageFrameGenerator::configure(const Size &size)
> > >         frameIndex_ = 0;
> > >         parameter_ = 0;
> > >
> > > -       for (unsigned int i = 0; i < imageFrames_->number.value_or(1); i++) {
> > > +       for (unsigned int i = 0; i < imageFrameDatas_.size(); i++) {
> > >                 /* Scale the imageFrameDatas_ to scaledY and scaledUV */
> > >                 unsigned int halfSizeWidth = (size.width + 1) / 2;
> > >                 unsigned int halfSizeHeight = (size.height + 1) / 2;
> > > @@ -139,7 +133,7 @@ int ImageFrameGenerator::generateFrame(const Size &size, const FrameBuffer *buff
> > >         auto planes = mappedFrameBuffer.planes();
> > >
> > >         /* Loop only around the number of images available */
> > > -       frameIndex_ %= imageFrames_->number.value_or(1);
> > > +       frameIndex_ %= imageFrameDatas_.size();
> > >
> > >         /* Write the scaledY and scaledUV to the mapped frame buffer */
> > >         libyuv::NV12Copy(scaledFrameDatas_[frameIndex_].Y.get(), size.width,
> > > diff --git a/src/libcamera/pipeline/virtual/image_frame_generator.h b/src/libcamera/pipeline/virtual/image_frame_generator.h
> > > index a68094a66..8554d647d 100644
> > > --- a/src/libcamera/pipeline/virtual/image_frame_generator.h
> > > +++ b/src/libcamera/pipeline/virtual/image_frame_generator.h
> > > @@ -10,9 +10,9 @@
> > >
> > >  #include <filesystem>
> > >  #include <memory>
> > > -#include <optional>
> > >  #include <stdint.h>
> > >  #include <sys/types.h>
> > > +#include <vector>
> > >
> > >  #include "frame_generator.h"
> > >
> > > @@ -20,8 +20,7 @@ namespace libcamera {
> > >
> > >  /* Frame configuration provided by the config file */
> > >  struct ImageFrames {
> > > -       std::filesystem::path path;
> > > -       std::optional<unsigned int> number;
> > > +       std::vector<std::filesystem::path> files;
> > >  };
> > >
> > >  class ImageFrameGenerator : public FrameGenerator
> > > diff --git a/src/libcamera/pipeline/virtual/meson.build b/src/libcamera/pipeline/virtual/meson.build
> > > index bb38c193c..4786fe2e0 100644
> > > --- a/src/libcamera/pipeline/virtual/meson.build
> > > +++ b/src/libcamera/pipeline/virtual/meson.build
> > > @@ -1,6 +1,7 @@
> > >  # SPDX-License-Identifier: CC0-1.0
> > >
> > >  libcamera_internal_sources += files([
> > > +    'config_parser.cpp',
> > >      'image_frame_generator.cpp',
> > >      'test_pattern_generator.cpp',
> > >      'virtual.cpp',
> > > diff --git a/src/libcamera/pipeline/virtual/virtual.cpp b/src/libcamera/pipeline/virtual/virtual.cpp
> > > index 1ad7417c7..cafd395c3 100644
> > > --- a/src/libcamera/pipeline/virtual/virtual.cpp
> > > +++ b/src/libcamera/pipeline/virtual/virtual.cpp
> > > @@ -36,6 +36,9 @@
> > >  #include "libcamera/internal/formats.h"
> > >  #include "libcamera/internal/framebuffer.h"
> > >  #include "libcamera/internal/pipeline_handler.h"
> > > +#include "libcamera/internal/yaml_parser.h"
> > > +
> > > +#include "pipeline/virtual/config_parser.h"
> > >
> > >  namespace libcamera {
> > >
> > > @@ -54,6 +57,13 @@ uint64_t currentTimestamp()
> > >
> > >  } /* namespace */
> > >
> > > +template<class... Ts>
> > > +struct overloaded : Ts... {
> > > +       using Ts::operator()...;
> > > +};
> > > +template<class... Ts>
> > > +overloaded(Ts...) -> overloaded<Ts...>;
> > > +
> > >  class VirtualCameraConfiguration : public CameraConfiguration
> > >  {
> > >  public:
> > > @@ -95,7 +105,7 @@ private:
> > >                 return static_cast<VirtualCameraData *>(camera->_d());
> > >         }
> > >
> > > -       void initFrameGenerator(Camera *camera);
> > > +       bool initFrameGenerator(Camera *camera);
> > >
> > >         DmaBufAllocator dmaBufAllocator_;
> > >
> > > @@ -104,15 +114,19 @@ private:
> > >
> > >  VirtualCameraData::VirtualCameraData(PipelineHandler *pipe,
> > >                                      const std::vector<Resolution> &supportedResolutions)
> > > -       : Camera::Private(pipe), supportedResolutions_(supportedResolutions)
> > > +       : Camera::Private(pipe)
> > >  {
> > > -       for (const auto &resolution : supportedResolutions_) {
> > > -               if (minResolutionSize_.isNull() || minResolutionSize_ > resolution.size)
> > > -                       minResolutionSize_ = resolution.size;
> > > +       config_.resolutions = supportedResolutions;
> > > +       for (const auto &resolution : config_.resolutions) {
> > > +               if (config_.minResolutionSize.isNull() || config_.minResolutionSize > resolution.size)
> > > +                       config_.minResolutionSize = resolution.size;
> > >
> > > -               maxResolutionSize_ = std::max(maxResolutionSize_, resolution.size);
> > > +               config_.maxResolutionSize = std::max(config_.maxResolutionSize, resolution.size);
> > >         }
> > >
> > > +       properties_.set(properties::PixelArrayActiveAreas,
> > > +                       { Rectangle(config_.maxResolutionSize) });
> > > +
> > >         /* \todo Support multiple streams and pass multi_stream_test */
> > >         streamConfigs_.resize(kMaxStream);
> > >  }
> > > @@ -140,7 +154,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
> > >         for (StreamConfiguration &cfg : config_) {
> > >                 bool adjusted = false;
> > >                 bool found = false;
> > > -               for (const auto &resolution : data_->supportedResolutions_) {
> > > +               for (const auto &resolution : data_->config_.resolutions) {
> > >                         if (resolution.size.width == cfg.size.width &&
> > >                             resolution.size.height == cfg.size.height) {
> > >                                 found = true;
> > > @@ -155,7 +169,7 @@ CameraConfiguration::Status VirtualCameraConfiguration::validate()
> > >                          * Defining the default logic in PipelineHandler to
> > >                          * find the closest resolution would be nice.
> > >                          */
> > > -                       cfg.size = data_->maxResolutionSize_;
> > > +                       cfg.size = data_->config_.maxResolutionSize;
> > >                         status = Adjusted;
> > >                         adjusted = true;
> > >                 }
> > > @@ -224,12 +238,12 @@ PipelineHandlerVirtual::generateConfiguration(Camera *camera,
> > >
> > >                 std::map<PixelFormat, std::vector<SizeRange>> streamFormats;
> > >                 PixelFormat pixelFormat = formats::NV12;
> > > -               streamFormats[pixelFormat] = { { data->minResolutionSize_,
> > > -                                                data->maxResolutionSize_ } };
> > > +               streamFormats[pixelFormat] = { { data->config_.minResolutionSize,
> > > +                                                data->config_.maxResolutionSize } };
> > >                 StreamFormats formats(streamFormats);
> > >                 StreamConfiguration cfg(formats);
> > >                 cfg.pixelFormat = pixelFormat;
> > > -               cfg.size = data->maxResolutionSize_;
> > > +               cfg.size = data->config_.maxResolutionSize;
> > >                 cfg.bufferCount = VirtualCameraConfiguration::kBufferCount;
> > >
> > >                 config->addConfiguration(cfg);
> > > @@ -246,6 +260,7 @@ int PipelineHandlerVirtual::configure(Camera *camera,
> > >         VirtualCameraData *data = cameraData(camera);
> > >         for (auto [i, c] : utils::enumerate(*config)) {
> > >                 c.setStream(&data->streamConfigs_[i].stream);
> > > +               /* Start reading the images/generating test patterns */
> > >                 data->streamConfigs_[i].frameGenerator->configure(c.size);
> > >         }
> > >
> > > @@ -315,56 +330,67 @@ bool PipelineHandlerVirtual::match([[maybe_unused]] DeviceEnumerator *enumerator
> > >
> > >         created_ = true;
> > >
> > > -       /* \todo Add virtual cameras according to a config file. */
> > > -
> > > -       std::vector<VirtualCameraData::Resolution> supportedResolutions;
> > > -       supportedResolutions.resize(2);
> > > -       supportedResolutions[0] = { .size = Size(1920, 1080), .frameRates = { 30 } };
> > > -       supportedResolutions[1] = { .size = Size(1280, 720), .frameRates = { 30 } };
> > > -
> > > -       std::unique_ptr<VirtualCameraData> data =
> > > -               std::make_unique<VirtualCameraData>(this, supportedResolutions);
> > > -
> > > -       data->properties_.set(properties::Location, properties::CameraLocationFront);
> > > -       data->properties_.set(properties::Model, "Virtual Video Device");
> > > -       data->properties_.set(properties::PixelArrayActiveAreas, { Rectangle(Size(1920, 1080)) });
> > > -
> > > -       /* \todo Set FrameDurationLimits based on config. */
> > > -       ControlInfoMap::Map controls;
> > > -       int64_t min_frame_duration = 33333, max_frame_duration = 33333;
> > > -       controls[&controls::FrameDurationLimits] = ControlInfo(min_frame_duration, max_frame_duration);
> > > -       std::vector<ControlValue> supportedFaceDetectModes{
> > > -               static_cast<int32_t>(controls::draft::FaceDetectModeOff),
> > > -       };
> > > -       controls[&controls::draft::FaceDetectMode] = ControlInfo(supportedFaceDetectModes);
> > > -       data->controlInfo_ = ControlInfoMap(std::move(controls), controls::controls);
> > > -
> > > -       /* Create and register the camera. */
> > > -       std::set<Stream *> streams;
> > > -       for (auto &streamConfig : data->streamConfigs_)
> > > -               streams.insert(&streamConfig.stream);
> > > +       File file(configurationFile("virtual", "virtual.yaml"));
> >
> > This tells me that the sample virtual.yaml file should probably be
> > installed in the libcamera data path...
> 
> Yes, updated the README.md.
> 
> 
> >
> > This version doesn't currently apply cleanly to master, but I did have
> > an branch with it on - and it rebased easily.
> 
> Rebased on tot in the next version.

Thanks - let try and get this merged then :-)

--
Kieran

> 
> 
> >
> > But it needs a new version posting at least to solve the SoB issues and
> > so with the above tackled you can add
> >
> > Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> >
> >
> > > +       bool isOpen = file.open(File::OpenModeFlag::ReadOnly);
> > > +       if (!isOpen) {
> > > +               LOG(Virtual, Error) << "Failed to open config file: " << file.fileName();
> > > +               return false;
> > > +       }
> > >
> > > -       const std::string id = "Virtual0";
> > > -       std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> > > +       ConfigParser parser;
> > > +       auto configData = parser.parseConfigFile(file, this);
> > > +       if (configData.size() == 0) {
> > > +               LOG(Virtual, Error) << "Failed to parse any cameras from the config file: "
> > > +                                   << file.fileName();
> > > +               return false;
> > > +       }
> > >
> > > -       initFrameGenerator(camera.get());
> > > +       /* Configure and register cameras with configData */
> > > +       for (auto &data : configData) {
> > > +               std::set<Stream *> streams;
> > > +               for (auto &streamConfig : data->streamConfigs_)
> > > +                       streams.insert(&streamConfig.stream);
> > > +               std::string id = data->config_.id;
> > > +               std::shared_ptr<Camera> camera = Camera::create(std::move(data), id, streams);
> > > +
> > > +               if (!initFrameGenerator(camera.get())) {
> > > +                       LOG(Virtual, Error) << "Failed to initialize frame "
> > > +                                           << "generator for camera: " << id;
> > > +                       continue;
> > > +               }
> > >
> > > -       registerCamera(std::move(camera));
> > > +               registerCamera(std::move(camera));
> > > +       }
> > >
> > >         resetCreated_ = true;
> > >
> > >         return true;
> > >  }
> > >
> > > -void PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
> > > +bool PipelineHandlerVirtual::initFrameGenerator(Camera *camera)
> > >  {
> > >         auto data = cameraData(camera);
> > > -       for (auto &streamConfig : data->streamConfigs_) {
> > > -               if (data->testPattern_ == TestPattern::DiagonalLines)
> > > -                       streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> > > -               else
> > > -                       streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> > > -       }
> > > +       auto &frame = data->config_.frame;
> > > +       std::visit(overloaded{
> > > +                          [&](TestPattern &testPattern) {
> > > +                                  for (auto &streamConfig : data->streamConfigs_) {
> > > +                                          if (testPattern == TestPattern::DiagonalLines)
> > > +                                                  streamConfig.frameGenerator = std::make_unique<DiagonalLinesGenerator>();
> > > +                                          else
> > > +                                                  streamConfig.frameGenerator = std::make_unique<ColorBarsGenerator>();
> > > +                                  }
> > > +                          },
> > > +                          [&](ImageFrames &imageFrames) {
> > > +                                  for (auto &streamConfig : data->streamConfigs_)
> > > +                                          streamConfig.frameGenerator = ImageFrameGenerator::create(imageFrames);
> > > +                          } },
> > > +                  frame);
> > > +
> > > +       for (auto &streamConfig : data->streamConfigs_)
> > > +               if (!streamConfig.frameGenerator)
> > > +                       return false;
> > > +
> > > +       return true;
> > >  }
> > >
> > >  REGISTER_PIPELINE_HANDLER(PipelineHandlerVirtual, "virtual")
> > > diff --git a/src/libcamera/pipeline/virtual/virtual.h b/src/libcamera/pipeline/virtual/virtual.h
> > > index 0b15f8d9c..8c4d6ae64 100644
> > > --- a/src/libcamera/pipeline/virtual/virtual.h
> > > +++ b/src/libcamera/pipeline/virtual/virtual.h
> > > @@ -7,6 +7,8 @@
> > >
> > >  #pragma once
> > >
> > > +#include <string>
> > > +#include <variant>
> > >  #include <vector>
> > >
> > >  #include <libcamera/geometry.h>
> > > @@ -15,10 +17,14 @@
> > >  #include "libcamera/internal/camera.h"
> > >  #include "libcamera/internal/pipeline_handler.h"
> > >
> > > +#include "frame_generator.h"
> > > +#include "image_frame_generator.h"
> > >  #include "test_pattern_generator.h"
> > >
> > >  namespace libcamera {
> > >
> > > +using VirtualFrame = std::variant<TestPattern, ImageFrames>;
> > > +
> > >  class VirtualCameraData : public Camera::Private
> > >  {
> > >  public:
> > > @@ -26,23 +32,28 @@ public:
> > >
> > >         struct Resolution {
> > >                 Size size;
> > > -               std::vector<int> frameRates;
> > > +               std::vector<int64_t> frameRates;
> > >         };
> > >         struct StreamConfig {
> > >                 Stream stream;
> > >                 std::unique_ptr<FrameGenerator> frameGenerator;
> > >         };
> > > +       /* The config file is parsed to the Configuration struct */
> > > +       struct Configuration {
> > > +               std::string id;
> > > +               std::vector<Resolution> resolutions;
> > > +               VirtualFrame frame;
> > > +
> > > +               Size maxResolutionSize;
> > > +               Size minResolutionSize;
> > > +       };
> > >
> > >         VirtualCameraData(PipelineHandler *pipe,
> > >                           const std::vector<Resolution> &supportedResolutions);
> > >
> > >         ~VirtualCameraData() = default;
> > >
> > > -       TestPattern testPattern_ = TestPattern::ColorBars;
> > > -
> > > -       const std::vector<Resolution> supportedResolutions_;
> > > -       Size maxResolutionSize_;
> > > -       Size minResolutionSize_;
> > > +       Configuration config_;
> > >
> > >         std::vector<StreamConfig> streamConfigs_;
> > >  };
> > > --
> > > 2.47.0.rc0.187.ge670bccf7e-goog
> > >