Hi, Le vendredi 29 mars 2024 à 18:23 +0900, Ming Qian a écrit : > 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. That seems ambiguous at best. What does it mean the "currently encoded frame" ? The OUTPUT and CAPTURE queue can be holding multiple frames. For "per frame" accurate reporting, I feel like we'd need something like Hans' read-only requests proposal [0]. Its basically a mechanism that let you attach request FD to capture buffer, so that supported controls can be saved per v4l2-buffer and read later on. https://patches.linaro.org/project/linux-media/patch/20210610113615.785359-12-hverkuil-cisco@xxxxxxxxx/ If this isn't what you wanted, we'll need a better definition. It might be helpful to explain what this is used for. Nicolas > + > .. 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"; > > /* 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; > + 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)
