Le mercredi 24 avril 2024 à 12:03 +0200, Hans Verkuil a écrit :
> On 29/03/2024 10:23, Ming Qian wrote:
> > Add a control V4L2_CID_MPEG_VIDEO_AVERAGE_QP to report the average qp
> > value of current encoded frame.
> >
> > Signed-off-by: Ming Qian <ming.qian@xxxxxxx>
> > ---
> > Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 4 ++++
> > drivers/media/v4l2-core/v4l2-ctrls-defs.c | 5 +++++
> > include/uapi/linux/v4l2-controls.h | 2 ++
> > 3 files changed, 11 insertions(+)
> >
> > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > index 2a165ae063fb..cef20b3f54ca 100644
> > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > @@ -1653,6 +1653,10 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
> > Quantization parameter for a P frame for FWHT. Valid range: from 1
> > to 31.
> >
> > +``V4L2_CID_MPEG_VIDEO_AVERAGE_QP (integer)``
> > + This read-only control returns the average qp value of the currently
> > + encoded frame. Applicable to the H264 and HEVC encoders.
>
> qp -> QP
>
> Why is this applicable to H264/HEVC only? I think it is fine for any codec.
Same question, though we should document the range, which will differ per-
codecs. We should also document to always use the specified range, rather then a
HW custom range. This way we don't endup with issues we have hit with other ill-
defined controls.
Nicolas
>
> This needs to document that the value applies to the last dequeued buffer
> (VIDIOC_DQBUF).
>
> > +
> > .. raw:: latex
> >
> > \normalsize
> > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > index 8696eb1cdd61..88e86e4e539d 100644
> > --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > @@ -972,6 +972,7 @@ const char *v4l2_ctrl_get_name(u32 id)
> > case V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES: return "Use LTR Frames";
> > case V4L2_CID_FWHT_I_FRAME_QP: return "FWHT I-Frame QP Value";
> > case V4L2_CID_FWHT_P_FRAME_QP: return "FWHT P-Frame QP Value";
> > + case V4L2_CID_MPEG_VIDEO_AVERAGE_QP: return "Average QP value";
>
> value -> Value
>
> Also move it up two lines so that it follows V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES
> rather than FWHT controls.
>
> >
> > /* VPX controls */
> > case V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS: return "VPX Number of Partitions";
> > @@ -1507,6 +1508,10 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
> > *max = 0xffffffffffffLL;
> > *step = 1;
> > break;
> > + case V4L2_CID_MPEG_VIDEO_AVERAGE_QP:
> > + *type = V4L2_CTRL_TYPE_INTEGER;
> > + *flags |= V4L2_CTRL_FLAG_VOLATILE | V4L2_CTRL_FLAG_READ_ONLY;
>
> Drop the volatile flag, this isn't a volatile value.
>
> > + break;
> > case V4L2_CID_PIXEL_RATE:
> > *type = V4L2_CTRL_TYPE_INTEGER64;
> > *flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> > index 99c3f5e99da7..974fd254e573 100644
> > --- a/include/uapi/linux/v4l2-controls.h
> > +++ b/include/uapi/linux/v4l2-controls.h
> > @@ -898,6 +898,8 @@ enum v4l2_mpeg_video_av1_level {
> > V4L2_MPEG_VIDEO_AV1_LEVEL_7_3 = 23
> > };
> >
> > +#define V4L2_CID_MPEG_VIDEO_AVERAGE_QP (V4L2_CID_CODEC_BASE + 657)
> > +
> > /* MPEG-class control IDs specific to the CX2341x driver as defined by V4L2 */
> > #define V4L2_CID_CODEC_CX2341X_BASE (V4L2_CTRL_CLASS_CODEC | 0x1000)
> > #define V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE (V4L2_CID_CODEC_CX2341X_BASE+0)
>
> Regards,
>
> Hans
>
