On 04/01/2021 06:09, Dikshita Agarwal wrote:
> Long Term Reference (LTR) frames are the frames that are encoded
> sometime in the past and stored in the DPB buffer list to be used
> as reference to encode future frames.
> This change adds controls to enable this feature.
>
> Signed-off-by: Dikshita Agarwal <dikshita@xxxxxxxxxxxxxx>
> ---
> .../userspace-api/media/v4l/ext-ctrls-codec.rst | 18 ++++++++++++++++++
> drivers/media/v4l2-core/v4l2-ctrls.c | 14 ++++++++++++++
> include/uapi/linux/v4l2-controls.h | 3 +++
> 3 files changed, 35 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> index 400774c..1675bcf 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -3637,3 +3637,21 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> - Selecting this value specifies that HEVC slices are expected
> to be prefixed by Annex B start codes. According to :ref:`hevc`
> valid start codes can be 3-bytes 0x000001 or 4-bytes 0x00000001.
> +
> +``V4L2_CID_MPEG_VIDEO_LTR_COUNT (integer)``
> + Specifies the number of Long Term Reference (LTR) frames encoder needs
> + to generate or keep. This is applicable to H264 and HEVC encoder.
This is applicable to the H264 and HEVC encoders.
> +
> +``V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX (integer)``
> + The current frame is marked as a Long Term Reference (LTR) frame
> + and given this LTR index which ranges from 0 to LTR_COUNT-1.
> + This is applicable to H264 and HEVC encoder and can be applied using
> + Request Api.
This is applicable to the H264 and HEVC encoders
Request Api -> the Request API
> + Source Rec. ITU-T H.264 (06/2019); Table 7.9
> +
> +``V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES (bitmask)``
> + Specifies the Long Term Reference (LTR) frame(s) to be used for
> + encoding the current frame.
> + This provides a bitmask which consists of bits [0, LTR_COUNT-1].
> + This is applicable to H264 and HEVC encoder and can be applied using
> + Request Api.
This is applicable to the H264 and HEVC encoders
Request Api -> the Request API
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index 16ab54f..2ad6b5a 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -950,6 +950,9 @@ const char *v4l2_ctrl_get_name(u32 id)
> case V4L2_CID_MPEG_VIDEO_MV_V_SEARCH_RANGE: return "Vertical MV Search Range";
> case V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER: return "Repeat Sequence Header";
> case V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME: return "Force Key Frame";
> + case V4L2_CID_MPEG_VIDEO_LTR_COUNT: return "LTR Count";
> + case V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX: return "frame LTR index";
Use proper capitals:
"Frame LTR Index"
> + case V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES: return "Use LTR Frames";
> case V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS: return "MPEG-2 Slice Parameters";
> case V4L2_CID_MPEG_VIDEO_MPEG2_QUANTIZATION: return "MPEG-2 Quantization Matrices";
> case V4L2_CID_FWHT_I_FRAME_QP: return "FWHT I-Frame QP Value";
> @@ -1277,6 +1280,17 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
> case V4L2_CID_MPEG_VIDEO_MV_V_SEARCH_RANGE:
> *type = V4L2_CTRL_TYPE_INTEGER;
> break;
> + case V4L2_CID_MPEG_VIDEO_LTR_COUNT:
> + *type = V4L2_CTRL_TYPE_INTEGER;
> + break;
> + case V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX:
> + *type = V4L2_CTRL_TYPE_INTEGER;
> + *flags |= V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
> + break;
> + case V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES:
> + *type = V4L2_CTRL_TYPE_BITMASK;
> + *flags |= V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
> + break;
> case V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME:
> case V4L2_CID_PAN_RESET:
> case V4L2_CID_TILT_RESET:
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index af8dda2..c0bb87b 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -422,6 +422,9 @@ enum v4l2_mpeg_video_multi_slice_mode {
> #define V4L2_CID_MPEG_VIDEO_MV_H_SEARCH_RANGE (V4L2_CID_CODEC_BASE+227)
> #define V4L2_CID_MPEG_VIDEO_MV_V_SEARCH_RANGE (V4L2_CID_CODEC_BASE+228)
> #define V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME (V4L2_CID_CODEC_BASE+229)
> +#define V4L2_CID_MPEG_VIDEO_LTR_COUNT (V4L2_CID_CODEC_BASE+230)
> +#define V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX (V4L2_CID_CODEC_BASE+231)
> +#define V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES (V4L2_CID_CODEC_BASE+232)
>
> /* CIDs for the MPEG-2 Part 2 (H.262) codec */
> #define V4L2_CID_MPEG_VIDEO_MPEG2_LEVEL (V4L2_CID_CODEC_BASE+270)
>
Regards,
Hans
