Re: [PATCH v6] [media] v4l: add I / P frame min max QP definitions

[Hans Verkuil]

On 3/21/19 3:20 AM, Fish Lin wrote:
> Add following V4L2 QP parameters for H.264:
> * V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MIN_QP
> * V4L2_CID_MPEG_VIDEO_H264_I_FRAME_MAX_QP
> * V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MIN_QP
> * V4L2_CID_MPEG_VIDEO_H264_P_FRAME_MAX_QP
> 
> 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 v5:
> - Adjust documentation wording.
> 
> Changelog since v4:
> - Fix patch subject and send again.
> 
> 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..5b2db52d3b4e 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 the H264 I frame to limit I frame
> +    quality to 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_I_FRAME_MAX_QP (integer)``
> +    Maximum quantization parameter for the H264 I frame to limit I frame
> +    quality to 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 the H264 P frame to limit P frame
> +    quality to 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 the H264 P frame to limit P frame
> +    quality to 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)

There is no need for a gap in numbering. Just start with +385.

Sorry for this, I missed that in the previous reviews. Everything else looks good
to me, so if you post a v7 I'll take it.

Thanks!

	Hans

> +#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)
> --
> 2.21.0.225.g810b269d1ac-goog
>