[{"id":37501,"web_url":"https://patchwork.libcamera.org/comment/37501/","msgid":"<176771565327.112111.2941659105078103679@isaac-ThinkPad-T16-Gen-2>","date":"2026-01-06T16:07:33","subject":"Re: [PATCH 03/11] libcamera: sensor: Add CameraSensorMemory class","submitter":{"id":215,"url":"https://patchwork.libcamera.org/api/people/215/","name":"Isaac Scott","email":"isaac.scott@ideasonboard.com"},"content":"Hi David,\n\nThank you for the patch!\n\nQuoting David Plowman (2025-12-10 16:15:18)\n> Representation of a \"camera\" that actually takes its input from\n> a memory buffer.\n> \n> libcamera is, unsurprisingly, very dependent on having a camera\n> connected to the system. But sometimes we may want to process raw\n> camera images from elsewhere, and we may not have a camera connected\n> to the system at all.\n> \n> In such cases, the path of a \"memory buffer\" through the code is eased\n> considerably by introducing the CameraSensorMemory class, which allows\n> the memory buffer to behave, to an extent at least, like a real\n> camera.\n> \n> Signed-off-by: David Plowman \n> ---\n> include/libcamera/internal/camera_sensor.h | 2 +\n> .../libcamera/internal/camera_sensor_memory.h | 110 ++++++++\n> include/libcamera/internal/meson.build | 1 +\n> src/libcamera/sensor/camera_sensor_memory.cpp | 241 ++++++++++++++++++\n> src/libcamera/sensor/meson.build | 1 +\n> 5 files changed, 355 insertions(+)\n> create mode 100644 include/libcamera/internal/camera_sensor_memory.h\n> create mode 100644 src/libcamera/sensor/camera_sensor_memory.cpp\n> \n> diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h\n> index e6b72d22..5580d6ec 100644\n> --- a/include/libcamera/internal/camera_sensor.h\n> +++ b/include/libcamera/internal/camera_sensor.h\n> @@ -49,6 +49,8 @@ public:\n> \n> virtual CameraLens *focusLens() = 0;\n> \n> + virtual bool isMemory() const { return false; }\n> +\n> virtual const std::vector &mbusCodes() const = 0;\n> virtual std::vector sizes(unsigned int mbusCode) const = 0;\n> virtual Size resolution() const = 0;\n> diff --git a/include/libcamera/internal/camera_sensor_memory.h b/include/libcamera/internal/camera_sensor_memory.h\n> new file mode 100644\n> index 00000000..944d4c96\n> --- /dev/null\n> +++ b/include/libcamera/internal/camera_sensor_memory.h\n> @@ -0,0 +1,110 @@\n> +/* SPDX-License-Identifier: LGPL-2.1-or-later */\n> +/*\n> + * Copyright (C) 2025, Raspberry Pi plc\n> + *\n> + * camera_sensor_memory.h - A fake camera sensor for reading raw data from memory\n> + */\n> +\n> +#pragma once\n> +\n> +#include \n> +#include \n> +#include \n> +\n> +#include \n> +\n> +#include \"libcamera/internal/camera_sensor.h\"\n> +\n> +namespace libcamera {\n> +\n> +class BayerFormat;\n> +class Camera;\n> +class CameraLens;\n> +class MediaEntity;\n> +class SensorConfiguration;\n> +\n> +struct CameraSensorProperties;\n> +\n> +enum class Orientation;\n> +\n> +LOG_DECLARE_CATEGORY(CameraSensor)\n> +\n> +class CameraSensorMemory : public CameraSensor, protected Loggable\n> +{\n> +public:\n> + CameraSensorMemory(const StreamConfiguration &rawInput, unsigned int mbusCode);\n> + ~CameraSensorMemory();\n> +\n> + static std::variant, int>\n> + match(MediaEntity *entity);\n> +\n> + const std::string &model() const override { return model_; }\n> + const std::string &id() const override { return id_; }\n> +\n> + const MediaEntity *entity() const override { return nullptr; }\n> + V4L2Subdevice *device() override { return nullptr; }\n> +\n> + CameraLens *focusLens() override { return nullptr; }\n> +\n> + virtual bool isMemory() const override { return true; }\n> +\n> + const std::vector &mbusCodes() const override;\n> + std::vector sizes(unsigned int mbusCode) const override;\n> + Size resolution() const override;\n> +\n> + V4L2SubdeviceFormat getFormat(Span mbusCodes,\n> + const Size &size,\n> + const Size maxSize) const override;\n> + int setFormat(V4L2SubdeviceFormat *format,\n> + Transform transform = Transform::Identity) override;\n> + int tryFormat(V4L2SubdeviceFormat *format) const override;\n> +\n> + int applyConfiguration(const SensorConfiguration &config,\n> + Transform transform = Transform::Identity,\n> + V4L2SubdeviceFormat *sensorFormat = nullptr) override;\n> +\n> + V4L2Subdevice::Stream imageStream() const override;\n> + std::optional embeddedDataStream() const override;\n> + V4L2SubdeviceFormat embeddedDataFormat() const override;\n> + int setEmbeddedDataEnabled(bool enable) override;\n> +\n> + const ControlList &properties() const override;\n> + int sensorInfo(IPACameraSensorInfo *info) const override;\n> + Transform computeTransform(Orientation *orientation) const override;\n> + BayerFormat::Order bayerOrder(Transform t) const override;\n> + Orientation mountingOrientation() const override;\n> +\n> + const ControlInfoMap &controls() const override;\n> + ControlList getControls(Span ids) override;\n> + int setControls(ControlList *ctrls) override;\n> +\n> + const std::vector &\n> + testPatternModes() const override { return testPatternModes_; }\n> + int setTestPatternMode(controls::draft::TestPatternModeEnum mode) override;\n> + const CameraSensorProperties::SensorDelays &sensorDelays() override;\n> +\n> +protected:\n> + std::string logPrefix() const override;\n> +\n> +private:\n> + LIBCAMERA_DISABLE_COPY(CameraSensorMemory)\n> +\n> + StreamConfiguration rawInput_;\n> +\n> + std::string model_;\n> + std::string id_;\n> +\n> + BayerFormat bayerFormat_;\n> + std::vector mbusCodes_;\n> +\n> + V4L2SubdeviceFormat v4l2SubdeviceFormat_;\n> +\n> + ControlInfoMap propertiesInfoMap_;\n> + ControlInfoMap controlsInfoMap_;\n> + ControlList properties_;\n> + ControlList controls_;\n> +\n> + std::vector testPatternModes_;\n> +};\n> +\n> +} /* namespace libcamera */\n> diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build\n> index e9540a2f..9994baae 100644\n> --- a/include/libcamera/internal/meson.build\n> +++ b/include/libcamera/internal/meson.build\n> @@ -10,6 +10,7 @@ libcamera_internal_headers = files([\n> 'camera_lens.h',\n> 'camera_manager.h',\n> 'camera_sensor.h',\n> + 'camera_sensor_memory.h',\n> 'camera_sensor_properties.h',\n> 'clock_recovery.h',\n> 'control_serializer.h',\n> diff --git a/src/libcamera/sensor/camera_sensor_memory.cpp b/src/libcamera/sensor/camera_sensor_memory.cpp\n> new file mode 100644\n> index 00000000..8e344016\n> --- /dev/null\n> +++ b/src/libcamera/sensor/camera_sensor_memory.cpp\n> @@ -0,0 +1,241 @@\n> +/* SPDX-License-Identifier: LGPL-2.1-or-later */\n> +/*\n> + * Copyright (C) 2025, Raspberry Pi plc\n> + *\n> + * camera_sensor_memory.cpp - A fake camera sensor for reading raw data from memory\n> + */\n> +\n> +#include \"libcamera/internal/camera_sensor_memory.h\"\n> +\n> +#include \n> +#include \n> +#include \n> +\n> +#include \n> +#include \n> +\n> +#include \n> +#include \n> +#include \n> +#include \n> +#include \n> +#include \n> +\n> +#include \n> +\n> +#include \"libcamera/internal/bayer_format.h\"\n> +#include \"libcamera/internal/formats.h\"\n> +#include \"libcamera/internal/v4l2_subdevice.h\"\n> +\n> +namespace libcamera {\n> +\n> +LOG_DECLARE_CATEGORY(CameraSensor)\n> +\n> +static bool v4l2SubdeviceFormatEqual(const V4L2SubdeviceFormat &lhs, const V4L2SubdeviceFormat &rhs)\n> +{\n> + return lhs.code == rhs.code && lhs.size == rhs.size && lhs.colorSpace == rhs.colorSpace;\n> +}\n> +\n> +CameraSensorMemory::CameraSensorMemory(const StreamConfiguration &rawInput, unsigned int mbusCode)\n> + : rawInput_(rawInput), properties_(propertiesInfoMap_), controls_(controlsInfoMap_)\n> +{\n> + model_ = \"memory\";\n> +\n> + std::ostringstream oss;\n> + oss << &rawInput;\n> + id_ = oss.str();\n> +\n> + /* The \"camera\" must appear to return the format the raw input wants. */\n> + bayerFormat_ = BayerFormat::fromPixelFormat(rawInput.pixelFormat);\n> + mbusCodes_ = { mbusCode };\n> +\n> + v4l2SubdeviceFormat_ = V4L2SubdeviceFormat{\n> + .code = mbusCode,\n> + .size = rawInput.size,\n> + .colorSpace = ColorSpace::Raw,\n> + };\n> +}\n> +\n> +CameraSensorMemory::~CameraSensorMemory() = default;\n> +\n> +std::variant, int>\n> +CameraSensorMemory::match([[maybe_unused]] MediaEntity *entity)\n> +{\n> + return {};\n> +}\n> +\n> +const std::vector &CameraSensorMemory::mbusCodes() const\n> +{\n> + return mbusCodes_;\n> +}\n> +\n> +std::vector CameraSensorMemory::sizes(unsigned int mbusCode) const\n> +{\n> + if (mbusCode == mbusCodes_[0])\n> + return { rawInput_.size };\n> + else\n> + return {};\n> +}\n> +\n> +Size CameraSensorMemory::resolution() const\n> +{\n> + return rawInput_.size;\n> +}\n> +\n> +V4L2SubdeviceFormat CameraSensorMemory::getFormat(Span mbusCodes,\n> + [[maybe_unused]] const Size &size,\n> + const Size maxSize) const\n> +{\n> + if (std::find(mbusCodes.begin(), mbusCodes.end(), mbusCodes_[0]) == mbusCodes.end())\n> + return {};\n> +\n> + if (maxSize.width < rawInput_.size.width || maxSize.height < rawInput_.size.height)\n> + return {};\n> +\n> + return v4l2SubdeviceFormat_;\n> +}\n> +\n> +int CameraSensorMemory::setFormat(V4L2SubdeviceFormat *format,\n> + Transform transform)\n> +{\n> + if (v4l2SubdeviceFormatEqual(*format, v4l2SubdeviceFormat_) &&\n> + transform == Transform::Identity)\n> + return 0;\n> +\n> + return -EPERM;\n> +}\n> +\n> +int CameraSensorMemory::tryFormat(V4L2SubdeviceFormat *format) const\n> +{\n> + if (v4l2SubdeviceFormatEqual(*format, v4l2SubdeviceFormat_))\n> + return 0;\n> +\n> + return -EPERM;\n> +}\n> +\n> +int CameraSensorMemory::applyConfiguration(const SensorConfiguration &config,\n> + Transform transform,\n> + V4L2SubdeviceFormat *sensorFormat)\n> +{\n> + if (config.bitDepth != bayerFormat_.bitDepth ||\n> + config.outputSize != rawInput_.size ||\n> + config.binning.binX != 1 || config.binning.binY != 1 ||\n> + config.skipping.xOddInc != 1 || config.skipping.xEvenInc != 1 ||\n> + config.skipping.yOddInc != 1 || config.skipping.yEvenInc != 1 ||\n> + transform != Transform::Identity)\n> + return -EPERM;\n> +\n> + if (sensorFormat)\n> + *sensorFormat = v4l2SubdeviceFormat_;\n> +\n> + return 0;\n> +}\n> +\n> +V4L2Subdevice::Stream CameraSensorMemory::imageStream() const\n> +{\n> + return V4L2Subdevice::Stream();\n> +}\n> +\n> +std::optional CameraSensorMemory::embeddedDataStream() const\n> +{\n> + return {};\n> +}\n> +\n> +V4L2SubdeviceFormat CameraSensorMemory::embeddedDataFormat() const\n> +{\n> + return {};\n> +}\n> +\n> +int CameraSensorMemory::setEmbeddedDataEnabled(bool enable)\n> +{\n> + return enable ? -ENOSTR : 0;\n> +}\n> +\n> +const ControlList &CameraSensorMemory::properties() const\n> +{\n> + return properties_;\n> +}\n> +\n> +int CameraSensorMemory::sensorInfo([[maybe_unused]] IPACameraSensorInfo *info) const\n> +{\n> + info->model = model();\n> +\n> + info->bitsPerPixel = bayerFormat_.bitDepth;\n> + info->cfaPattern = properties::draft::RGB;\n> +\n> + info->activeAreaSize = rawInput_.size;\n> + info->analogCrop = Rectangle(rawInput_.size);\n> + info->outputSize = rawInput_.size;\n> +\n> + /*\n> + * These are meaningless for us, fill with ones rather than zeros because the\n> + * code will divide by some of these numbers.\n> + */\n> + info->pixelRate = 1;\n> + info->minLineLength = 1;\n> + info->maxLineLength = 1;\n> + info->minFrameLength = 1;\n> + info->maxFrameLength = 1;\n> +\n> + return 0;\n> +}\n> +\n> +Transform CameraSensorMemory::computeTransform(Orientation *orientation) const\n> +{\n> + *orientation = Orientation::Rotate0;\n> + return Transform::Identity;\n> +}\n> +\n> +BayerFormat::Order CameraSensorMemory::bayerOrder([[maybe_unused]] Transform t) const\n> +{\n> + return bayerFormat_.order;\n> +}\n> +\n> +Orientation CameraSensorMemory::mountingOrientation() const\n> +{\n> + return Orientation::Rotate0;\n> +}\n> +\n> +const ControlInfoMap &CameraSensorMemory::controls() const\n> +{\n> + return *controls_.infoMap();\n> +}\n> +\n> +ControlList CameraSensorMemory::getControls([[maybe_unused]] Span ids)\n> +{\n> + return ControlList();\n> +}\n> +\n> +int CameraSensorMemory::setControls([[maybe_unused]] ControlList *ctrls)\n> +{\n> + return -EPERM;\n> +}\n> +\n> +int CameraSensorMemory::setTestPatternMode([[maybe_unused]] controls::draft::TestPatternModeEnum mode)\n> +{\n> + return -EPERM;\n> +}\n> +\n> +const CameraSensorProperties::SensorDelays &CameraSensorMemory::sensorDelays()\n> +{\n> + static constexpr CameraSensorProperties::SensorDelays defaultSensorDelays = {\n> + .exposureDelay = 2,\n> + .gainDelay = 1,\n> + .vblankDelay = 2,\n> + .hblankDelay = 2,\n> + };\n> +\n> + return defaultSensorDelays; /* but doesn't mean anything */\n> +}\n> +\n> +std::string CameraSensorMemory::logPrefix() const\n> +{\n> + return \"'memory'\";\n> +}\n> +\n> +/*\n> + * We're not going to register this camera sensor as it doesn't match media entities\n> + * like other sensors. Pipeline handlers will have to call it explicitly.\n> + */\n\nVery interesting!\n\nReviewed-by: Isaac Scott \n\n> +\n> +} /* namespace libcamera */\n> diff --git a/src/libcamera/sensor/meson.build b/src/libcamera/sensor/meson.build\n> index dce74ed6..b9b87612 100644\n> --- a/src/libcamera/sensor/meson.build\n> +++ b/src/libcamera/sensor/meson.build\n> @@ -3,6 +3,7 @@\n> libcamera_internal_sources += files([\n> 'camera_sensor.cpp',\n> 'camera_sensor_legacy.cpp',\n> + 'camera_sensor_memory.cpp',\n> 'camera_sensor_properties.cpp',\n> 'camera_sensor_raw.cpp',\n> ])\n> -- \n> 2.47.3\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 6D5A1BDCC0\n\tfor ;\n\tTue, 6 Jan 2026 16:07:38 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id A725361FA0;\n\tTue, 6 Jan 2026 17:07:37 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 203C161F9F\n\tfor ;\n\tTue, 6 Jan 2026 17:07:36 +0100 (CET)","from thinkpad.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust6594.18-1.cable.virginm.net [86.31.185.195])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id F1310129;\n\tTue, 6 Jan 2026 17:07:14 +0100 (CET)"],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"bg3+4bt2\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1767715635;\n\tbh=FSd1Wwd55W9CwrLM0xLxUBSzYpKBkLYWjtcg/O/USE8=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=bg3+4bt2PfYQvxn7AbXOrdRnIraevYmAJZEo38uSeK/g44XD2kg/b9a2SHhe/NTzU\n\tiQDAC/4HJr90W4KhPzYgruG4UzVbg16N8ydhgnKViS5KHKNIGQhpCD1KtHQsTQkddk\n\tMBOmUZXd3bLuQ4dkYtaxA9jbCv1ebvNni2izQnbQ=","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20251210164055.17856-4-david.plowman@raspberrypi.com>","References":"<20251210164055.17856-1-david.plowman@raspberrypi.com>\n\t<20251210164055.17856-4-david.plowman@raspberrypi.com>","Subject":"Re: [PATCH 03/11] libcamera: sensor: Add CameraSensorMemory class","From":"Isaac Scott ","Cc":"David Plowman ","To":"David Plowman ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Tue, 06 Jan 2026 16:07:33 +0000","Message-ID":"<176771565327.112111.2941659105078103679@isaac-ThinkPad-T16-Gen-2>","User-Agent":"alot/0.10","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]