[libcamera-devel] [PATCH v2] libcamera: add support for planar YUV422 and YUV420 formats

[Kieran Bingham]

Hi David, Laurent,

On 22/06/2020 05:38, Laurent Pinchart wrote:
> From: David Plowman <david.plowman at raspberrypi.com>
> 
> These formats can be helpful when downstream applications or libraries
> support them natively (avoiding a costly conversion).
> 
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Changes since v1:
> 
> - Rebase on top of formats rework
> - Fix number of planes in formats descriptions
> ---
>  src/libcamera/formats.cpp          | 14 ++++++++++++++
>  src/libcamera/formats.yaml         |  5 +++++
>  src/libcamera/v4l2_pixelformat.cpp |  2 ++
>  src/v4l2/v4l2_camera_proxy.cpp     |  4 +++-
>  4 files changed, 24 insertions(+), 1 deletion(-)
> 
> David, could you please test this and provide a Tested-by tag (and
> Reviewed-by too if possible) ?
> 
> diff --git a/src/libcamera/formats.cpp b/src/libcamera/formats.cpp
> index 97e986786cc8..c0b53ce7cc97 100644
> --- a/src/libcamera/formats.cpp
> +++ b/src/libcamera/formats.cpp
> @@ -270,6 +270,20 @@ const std::map<PixelFormat, PixelFormatInfo> pixelFormatInfo{
>  		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
>  		.packed = false,
>  	} },
> +	{ formats::YUV420, {
> +		.format = PixelFormat(formats::YUV420),
> +		.v4l2Format = V4L2PixelFormat(V4L2_PIX_FMT_YUV420),
> +		.bitsPerPixel = 12,
> +		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
> +		.packed = false,
> +	} },
> +	{ formats::YUV422, {
> +		.format = PixelFormat(formats::YUV422),
> +		.v4l2Format = V4L2PixelFormat(V4L2_PIX_FMT_YUV422P),
> +		.bitsPerPixel = 16,
> +		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
> +		.packed = false,
> +	} },
>  
>  	/* Greyscale formats. */
>  	{ formats::R8, {
> diff --git a/src/libcamera/formats.yaml b/src/libcamera/formats.yaml
> index a6841c618f93..ce06dbc41aa1 100644
> --- a/src/libcamera/formats.yaml
> +++ b/src/libcamera/formats.yaml
> @@ -53,6 +53,11 @@ formats:
>    - NV42:
>        fourcc: DRM_FORMAT_NV42
>  
> +  - YUV420:
> +      fourcc: DRM_FORMAT_YUV420
> +  - YUV422:
> +      fourcc: DRM_FORMAT_YUV422
> +
>    - MJPEG:
>        fourcc: DRM_FORMAT_MJPEG
>  
> diff --git a/src/libcamera/v4l2_pixelformat.cpp b/src/libcamera/v4l2_pixelformat.cpp
> index 741f6c2646bc..6745d17d4926 100644
> --- a/src/libcamera/v4l2_pixelformat.cpp
> +++ b/src/libcamera/v4l2_pixelformat.cpp
> @@ -63,6 +63,8 @@ const std::map<V4L2PixelFormat, PixelFormat> vpf2pf{
>  	{ V4L2PixelFormat(V4L2_PIX_FMT_NV61), formats::NV61 },
>  	{ V4L2PixelFormat(V4L2_PIX_FMT_NV12), formats::NV12 },
>  	{ V4L2PixelFormat(V4L2_PIX_FMT_NV21), formats::NV21 },
> +	{ V4L2PixelFormat(V4L2_PIX_FMT_YUV420), formats::YUV420 },
> +	{ V4L2PixelFormat(V4L2_PIX_FMT_YUV422P), formats::YUV422 },
>  
>  	/* Greyscale formats. */
>  	{ V4L2PixelFormat(V4L2_PIX_FMT_GREY), formats::R8 },
> diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
> index bf47aa7ee633..86b87e379b98 100644
> --- a/src/v4l2/v4l2_camera_proxy.cpp
> +++ b/src/v4l2/v4l2_camera_proxy.cpp
> @@ -560,7 +560,7 @@ struct PixelFormatInfo {
>  
>  namespace {
>  
> -static const std::array<PixelFormatInfo, 14> pixelFormatInfo = {{
> +static const std::array<PixelFormatInfo, 16> pixelFormatInfo = {{
>  	/* RGB formats. */
>  	{ formats::RGB888,	V4L2_PIX_FMT_BGR24,	1, {{ { 24, 1, 1 }, {  0, 0, 0 }, {  0, 0, 0 } }} },
>  	{ formats::BGR888,	V4L2_PIX_FMT_RGB24,	1, {{ { 24, 1, 1 }, {  0, 0, 0 }, {  0, 0, 0 } }} },
> @@ -577,6 +577,8 @@ static const std::array<PixelFormatInfo, 14> pixelFormatInfo = {{
>  	{ formats::NV61,	V4L2_PIX_FMT_NV61,	2, {{ {  8, 1, 1 }, { 16, 2, 1 }, {  0, 0, 0 } }} },
>  	{ formats::NV24,	V4L2_PIX_FMT_NV24,	2, {{ {  8, 1, 1 }, { 16, 1, 1 }, {  0, 0, 0 } }} },
>  	{ formats::NV42,	V4L2_PIX_FMT_NV42,	2, {{ {  8, 1, 1 }, { 16, 1, 1 }, {  0, 0, 0 } }} },
> +	{ formats::YUV420,	V4L2_PIX_FMT_YUV420,	3, {{ {  8, 1, 1 }, {  8, 2, 2 }, {  8, 2, 2 } }} },
> +	{ formats::YUV422,	V4L2_PIX_FMT_YUV422P,	3, {{ {  8, 1, 1 }, {  8, 2, 1 }, {  8, 2, 1 } }} },

Wow, what fun. One v4l2 format gets marked with a P and one doesn't. I
love the consistency ;-)

But - I've dug into the include/uapi/linux/videodev2.h and
include/uapi/drm/drm_fourcc.h headers, and as best I can see these are
correct.

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


>  	/* Compressed formats. */
>  	/*
>  	 * \todo Get a better image size estimate for MJPEG, via
> 

-- 
Regards
--
Kieran