This subject line is insanely long :-) Please use a short subject line for v5 (i.e. "Add V4L2 QP parameters for H.264") and mention the actual parameters you are adding in the commit log. Some more comments below: On 3/15/19 9:40 AM, Fish Lin wrote: > These controls will limit QP range for intra and inter frame, > provide more manual control to improve video encode quality. > > Signed-off-by: Fish Lin <linfish@xxxxxxxxxx> > --- > Changelog since v3: > - Put document in ext-ctrls-codec.rst instead of extended-controls.rst > (which was previous version). > > Changelog since v2: > - Add interaction with V4L2_CID_MPEG_VIDEO_H264_MIN/MAX_QP > description in the document. > > Changelog since v1: > - Add description in document. > > .../media/uapi/v4l/ext-ctrls-codec.rst | 24 +++++++++++++++++++ > drivers/media/v4l2-core/v4l2-ctrls.c | 4 ++++ > include/uapi/linux/v4l2-controls.h | 6 +++++ > 3 files changed, 34 insertions(+) > > diff --git a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > index c97fb7923be5..de60b2e788eb 100644 > --- a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > +++ b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > @@ -1048,6 +1048,30 @@ enum v4l2_mpeg_video_h264_entropy_mode - > Quantization parameter for an B frame for H264. Valid range: from 0 > to 51. > > +``V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MIN_QP (integer)`` > + Minimum quantization parameter for H264 I frame, to limit I frame H264 -> the H264 frame, to -> frame to Same below. > + quality in a range. Valid range: from 0 to 51. If in -> to (you limit a value *to* a range, not 'in a range') Same below. Regards, Hans > + V4L2_CID_MPEG_VIDEO_H264_MIN_QP is also set, the quantization parameter > + should be chosen to meet both requirements. > + > +``V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MAX_QP (integer)`` > + Maximum quantization parameter for H264 I frame, to limit I frame > + quality in a range. Valid range: from 0 to 51. If > + V4L2_CID_MPEG_VIDEO_H264_MAX_QP is also set, the quantization parameter > + should be chosen to meet both requirements. > + > +``V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MIN_QP (integer)`` > + Minimum quantization parameter for H264 P frame, to limit P frame > + quality in a range. Valid range: from 0 to 51. If > + V4L2_CID_MPEG_VIDEO_H264_MIN_QP is also set, the quantization parameter > + should be chosen to meet both requirements. > + > +``V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MAX_QP (integer)`` > + Maximum quantization parameter for H264 P frame, to limit P frame > + quality in a range. Valid range: from 0 to 51. If > + V4L2_CID_MPEG_VIDEO_H264_MAX_QP is also set, the quantization parameter > + should be chosen to meet both requirements. > + > ``V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP (integer)`` > Quantization parameter for an I frame for MPEG4. Valid range: from 1 > to 31. > diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c > index b79d3bbd8350..115fb8debe23 100644 > --- a/drivers/media/v4l2-core/v4l2-ctrls.c > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c > @@ -828,6 +828,10 @@ const char *v4l2_ctrl_get_name(u32 id) > case V4L2_CID_MPEG_VIDEO_H264_CONSTRAINED_INTRA_PREDICTION: > return "H264 Constrained Intra Pred"; > case V4L2_CID_MPEG_VIDEO_H264_CHROMA_QP_INDEX_OFFSET: return "H264 Chroma QP Index Offset"; > + case V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MIN_QP: return "H264 I-Frame Minimum QP Value"; > + case V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MAX_QP: return "H264 I-Frame Maximum QP Value"; > + case V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MIN_QP: return "H264 P-Frame Minimum QP Value"; > + case V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MAX_QP: return "H264 P-Frame Maximum QP Value"; > case V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP: return "MPEG4 I-Frame QP Value"; > case V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP: return "MPEG4 P-Frame QP Value"; > case V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP: return "MPEG4 B-Frame QP Value"; > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h > index 06479f2fb3ae..4421baa84177 100644 > --- a/include/uapi/linux/v4l2-controls.h > +++ b/include/uapi/linux/v4l2-controls.h > @@ -535,6 +535,12 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type { > #define V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP (V4L2_CID_MPEG_BASE+382) > #define V4L2_CID_MPEG_VIDEO_H264_CONSTRAINED_INTRA_PREDICTION (V4L2_CID_MPEG_BASE+383) > #define V4L2_CID_MPEG_VIDEO_H264_CHROMA_QP_INDEX_OFFSET (V4L2_CID_MPEG_BASE+384) > + > +#define V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MIN_QP (V4L2_CID_MPEG_BASE+390) > +#define V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MAX_QP (V4L2_CID_MPEG_BASE+391) > +#define V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MIN_QP (V4L2_CID_MPEG_BASE+392) > +#define V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MAX_QP (V4L2_CID_MPEG_BASE+393) > + > #define V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP (V4L2_CID_MPEG_BASE+400) > #define V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP (V4L2_CID_MPEG_BASE+401) > #define V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP (V4L2_CID_MPEG_BASE+402) >