Commit 4ad1b0d4 authored by Maheshwar Ajja's avatar Maheshwar Ajja Committed by Mauro Carvalho Chehab
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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: default avatarMaheshwar Ajja <majja@codeaurora.org>
Reviewed-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarStanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 73d513e4

Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst

+10 −0
Original line number Diff line number Diff line
@@ -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).

drivers/media/v4l2-core/v4l2-ctrls.c

+2 −0
Original line number Diff line number Diff line
@@ -200,6 +200,7 @@ const char * const *v4l2_ctrl_get_menu(u32 id) 
	static const char * const mpeg_video_bitrate_mode[] = {

		"Variable Bitrate",

		"Constant Bitrate",

		"Constant Quality",

		NULL

	};

	static const char * const mpeg_stream_type[] = {
@@ -832,6 +833,7 @@ const char *v4l2_ctrl_get_name(u32 id) 
	case V4L2_CID_MPEG_VIDEO_GOP_CLOSURE:	return "Video GOP Closure";

	case V4L2_CID_MPEG_VIDEO_PULLDOWN:	return "Video Pulldown";

	case V4L2_CID_MPEG_VIDEO_BITRATE_MODE:	return "Video Bitrate Mode";

	case V4L2_CID_MPEG_VIDEO_CONSTANT_QUALITY:	return "Constant Quality";

	case V4L2_CID_MPEG_VIDEO_BITRATE:	return "Video Bitrate";

	case V4L2_CID_MPEG_VIDEO_BITRATE_PEAK:	return "Video Peak Bitrate";

	case V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION: return "Video Temporal Decimation";

include/uapi/linux/v4l2-controls.h

+2 −0
Original line number Diff line number Diff line
@@ -375,6 +375,7 @@ enum v4l2_mpeg_video_aspect { 
enum v4l2_mpeg_video_bitrate_mode {

	V4L2_MPEG_VIDEO_BITRATE_MODE_VBR = 0,

	V4L2_MPEG_VIDEO_BITRATE_MODE_CBR = 1,

	V4L2_MPEG_VIDEO_BITRATE_MODE_CQ  = 2,

};

#define V4L2_CID_MPEG_VIDEO_BITRATE		(V4L2_CID_MPEG_BASE+207)

#define V4L2_CID_MPEG_VIDEO_BITRATE_PEAK	(V4L2_CID_MPEG_BASE+208)
@@ -742,6 +743,7 @@ enum v4l2_cid_mpeg_video_hevc_size_of_length_field { 
#define V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L6_BR	(V4L2_CID_MPEG_BASE + 642)

#define V4L2_CID_MPEG_VIDEO_REF_NUMBER_FOR_PFRAMES	(V4L2_CID_MPEG_BASE + 643)

#define V4L2_CID_MPEG_VIDEO_PREPEND_SPSPPS_TO_IDR	(V4L2_CID_MPEG_BASE + 644)

#define V4L2_CID_MPEG_VIDEO_CONSTANT_QUALITY		(V4L2_CID_MPEG_BASE + 645)



/*  MPEG-class control IDs specific to the CX2341x driver as defined by V4L2 */

#define V4L2_CID_MPEG_CX2341X_BASE				(V4L2_CTRL_CLASS_MPEG | 0x1000)

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