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| author | Maheshwar Ajja <majja@codeaurora.org> | 2020-05-23 03:05:26 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+huawei@kernel.org> | 2020-09-01 14:13:29 +0200 |
| commit | 4ad1b0d410c88c7c8e8fd1298c9d2293b651e35c (patch) | |
| tree | b3e972f783e5484061c8e4af8ac896075b8a076e /Documentation/userspace-api | |
| parent | 73d513e45ac7e5219388bee98d36aae820d2876c (diff) | |
media: v4l2-ctrls: Add encoder constant quality control
When V4L2_CID_MPEG_VIDEO_BITRATE_MODE value is
V4L2_MPEG_VIDEO_BITRATE_MODE_CQ, encoder will produce
constant quality output indicated by
V4L2_CID_MPEG_VIDEO_CONSTANT_QUALITY control value.
Encoder will choose appropriate quantization parameter
and bitrate to produce requested frame quality level.
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Diffstat (limited to 'Documentation/userspace-api')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst index e2b94b1d0ab0..ebd367dcf8b9 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst @@ -581,6 +581,8 @@ enum v4l2_mpeg_video_bitrate_mode - - Variable bitrate * - ``V4L2_MPEG_VIDEO_BITRATE_MODE_CBR`` - Constant bitrate + * - ``V4L2_MPEG_VIDEO_BITRATE_MODE_CQ`` + - Constant quality @@ -592,6 +594,14 @@ enum v4l2_mpeg_video_bitrate_mode - the average video bitrate. It is ignored if the video bitrate mode is set to constant bitrate. +``V4L2_CID_MPEG_VIDEO_CONSTANT_QUALITY (integer)`` + Constant quality level control. This control is applicable when + ``V4L2_CID_MPEG_VIDEO_BITRATE_MODE`` value is + ``V4L2_MPEG_VIDEO_BITRATE_MODE_CQ``. Valid range is 1 to 100 + where 1 indicates lowest quality and 100 indicates highest quality. + Encoder will decide the appropriate quantization parameter and + bitrate to produce requested frame quality. + ``V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION (integer)`` For every captured frame, skip this many subsequent frames (default 0). |