[libcamera-devel] [RFC PATCH 1/2] libcamera: v4l2_videodevice: Get formats even if no framesizes

[Jacopo Mondi]

Hi Paul,

On Tue, Jul 19, 2022 at 09:10:02PM +0900, Paul Elder via libcamera-devel wrote:
> V4L2VideoDevice::formats() returns an empty list of formats if enumSizes
> fails, including if the driver doesn't implement ENUM_FRAMESIZES.
>
> Add an optional ignoreSizes parameter to formats() so that it can still
> be used when the pipeline handler knows that its driver doesn't
> implement ENUM_FRAMESIZES.

I think we shall require drivers to implement ENUM_FRAMESIZES, instead
of allowing them to ignore it.

I'm surprised the rkisp1 capture device does not support
.vidioc_enum_framesizes(). Should that be fixed in the driver ?

>
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> ---
>  include/libcamera/internal/v4l2_videodevice.h |  2 +-
>  src/libcamera/v4l2_videodevice.cpp            | 12 ++++++++----
>  2 files changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/include/libcamera/internal/v4l2_videodevice.h b/include/libcamera/internal/v4l2_videodevice.h
> index 8525acbc..6cc9be85 100644
> --- a/include/libcamera/internal/v4l2_videodevice.h
> +++ b/include/libcamera/internal/v4l2_videodevice.h
> @@ -205,7 +205,7 @@ public:
>  	int getFormat(V4L2DeviceFormat *format);
>  	int tryFormat(V4L2DeviceFormat *format);
>  	int setFormat(V4L2DeviceFormat *format);
> -	Formats formats(uint32_t code = 0);
> +	Formats formats(uint32_t code = 0, bool ignoreSizes = false);
>
>  	int setSelection(unsigned int target, Rectangle *rect);
>
> diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp
> index 63911339..b8bd4bc4 100644
> --- a/src/libcamera/v4l2_videodevice.cpp
> +++ b/src/libcamera/v4l2_videodevice.cpp
> @@ -1045,14 +1045,18 @@ int V4L2VideoDevice::trySetFormatSingleplane(V4L2DeviceFormat *format, bool set)
>   *
>   * \return A list of the supported video device formats
>   */
> -V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code)
> +V4L2VideoDevice::Formats V4L2VideoDevice::formats(uint32_t code, bool ignoreSizes)
>  {
>  	Formats formats;
>
>  	for (V4L2PixelFormat pixelFormat : enumPixelformats(code)) {
> -		std::vector<SizeRange> sizes = enumSizes(pixelFormat);
> -		if (sizes.empty())
> -			return {};
> +		std::vector<SizeRange> sizes;
> +
> +		if (!ignoreSizes) {
> +			sizes = enumSizes(pixelFormat);
> +			if (sizes.empty())
> +				return {};
> +		}
>
>  		if (formats.find(pixelFormat) != formats.end()) {
>  			LOG(V4L2, Error)
> --
> 2.30.2
>