[libcamera-devel,2/2] libcamera: pipeline: uvcvideo: add pipeline handler for uvcvideo

299 diff mbox series

Provide a pipeline handler for uvcvideo devices. The entity names for
uvc devices are different for different cameras so matching on entity
names is not possible in the generic case. This leaves options to create
specialized uvc pipeline handlers if needed to fit a specific models
needs.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
---
 src/libcamera/pipeline/meson.build  |  1 +
 src/libcamera/pipeline/uvcvideo.cpp | 59 +++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 src/libcamera/pipeline/uvcvideo.cpp

Hi Niklas,

Thank you for the patch.

On Mon, Jan 21, 2019 at 04:30:05PM +0100, Niklas Söderlund wrote:
> Provide a pipeline handler for uvcvideo devices. The entity names for
> uvc devices are different for different cameras so matching on entity
> names is not possible in the generic case. This leaves options to create
> specialized uvc pipeline handlers if needed to fit a specific models

s/uvc/UVC/
s/models/model's/

> needs.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
> ---
>  src/libcamera/pipeline/meson.build  |  1 +
>  src/libcamera/pipeline/uvcvideo.cpp | 59 +++++++++++++++++++++++++++++
>  2 files changed, 60 insertions(+)
>  create mode 100644 src/libcamera/pipeline/uvcvideo.cpp
> 
> diff --git a/src/libcamera/pipeline/meson.build b/src/libcamera/pipeline/meson.build
> index 615ecd20f1a21141..4da5d8cf9c4384bb 100644
> --- a/src/libcamera/pipeline/meson.build
> +++ b/src/libcamera/pipeline/meson.build
> @@ -1,3 +1,4 @@
>  libcamera_sources += files([
> +    'uvcvideo.cpp',
>      'vimc.cpp',
>  ])
> diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
> new file mode 100644
> index 0000000000000000..2579782e90caec5a
> --- /dev/null
> +++ b/src/libcamera/pipeline/uvcvideo.cpp
> @@ -0,0 +1,59 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2019, Google Inc.
> + *
> + * uvcvideo.cpp - Pipeline handler for uvcvideo devices
> + */
> +
> +#include <libcamera/camera.h>
> +#include <libcamera/camera_manager.h>
> +
> +#include "device_enumerator.h"
> +#include "media_device.h"
> +#include "pipeline_handler.h"
> +
> +namespace libcamera {
> +
> +class PipeHandlerUvcvideo : public PipelineHandler

How about PipelineHandlerUVC to retain the common prefix ?

> +{
> +public:
> +	PipeHandlerUvcvideo();
> +	~PipeHandlerUvcvideo();
> +
> +	bool match(CameraManager *manager, DeviceEnumerator *enumerator);
> +
> +private:
> +	MediaDevice *dev_;
> +};
> +
> +PipeHandlerUvcvideo::PipeHandlerUvcvideo()
> +	: dev_(nullptr)
> +{
> +}
> +
> +PipeHandlerUvcvideo::~PipeHandlerUvcvideo()
> +{
> +	if (dev_)
> +		dev_->release();
> +}
> +
> +bool PipeHandlerUvcvideo::match(CameraManager *manager, DeviceEnumerator *enumerator)
> +{
> +	DeviceMatch dm("uvcvideo");
> +
> +	dev_ = enumerator->search(dm);
> +
> +	if (!dev_)
> +		return false;
> +
> +	dev_->acquire();
> +
> +	std::shared_ptr<Camera> camera = Camera::create(dev_->model());

Does this guarantee unicity of the name ? I think we'll need more than
that, but it can probably be fixed later. I foresee the need for a
machine-parsable name and a human-readable description, along the lines
of "uvcvideo/1-5:1.0" and "Integrated_Webcam_HD", or
"uvcvideo/3-1.3:1.0" and "Logitech Portable Webcam C905 on USB port
3-1.3" (those are real examples).

> +	manager->addCamera(std::move(camera));
> +
> +	return true;

While this doesn't do much, it's a stumb that allows enumerating cameras
on most development platforms, so it's very useful as such. Let's get it
in, with the above issues fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +}
> +
> +REGISTER_PIPELINE_HANDLER(PipeHandlerUvcvideo);
> +
> +} /* namespace libcamera */