[libcamera-devel] [PATCH] v4l2: Extend device caps with V4L2_CAP_STREAMING

[Kieran Bingham]

Hi Nicolas,

On 18/01/2020 21:31, Nicolas Dufresne wrote:
> From: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> 
> This capability tells the application that mmap() is supported. GStreamer
> would return an error saying there there is no input/output method supported
> by this device otherwise. This was tested with:
> 
> LD_PRELOAD=$(pwd)/build/src/v4l2/v4l2-compat.so GST_DEBUG="v4l2*:7" gst-launch-1.0 v4l2src ! videoconvert ! autovideosink
> 

We should start documenting these commands in an FAQ or some
documentation somewhere so we can track examples.


> With this patch, GStreamer will reach playing state. It then blocks waiting on
> poll() which is not implemented yet on our side.

Sounds like good progress all the same

> 
> Signed-off-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
> ---
>  src/v4l2/v4l2_camera_proxy.cpp | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
> index 3013a3d..e58fd6a 100644
> --- a/src/v4l2/v4l2_camera_proxy.cpp
> +++ b/src/v4l2/v4l2_camera_proxy.cpp
> @@ -179,7 +179,7 @@ void V4L2CameraProxy::querycap(std::shared_ptr<Camera> camera)
>  		       sizeof(capabilities_.bus_info));
>  	/* \todo Put this in a header/config somewhere. */
>  	capabilities_.version = KERNEL_VERSION(5, 2, 0);
> -	capabilities_.device_caps = V4L2_CAP_VIDEO_CAPTURE;
> +	capabilities_.device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
>  	capabilities_.capabilities = capabilities_.device_caps
>  				   | V4L2_CAP_DEVICE_CAPS;
>  	memset(capabilities_.reserved, 0, sizeof(capabilities_.reserved));


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

-- 
Regards
--
Kieran