On 05/07/2020 14:11, Stanimir Varbanov wrote:
> Adds encoders standard v4l2 control for frame-skip. The control
> is a copy of a custom encoder control so that other v4l2 encoder
> drivers can use it.
>
> Signed-off-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx>
Reviewed-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
But see note at the end.
> ---
> .../media/v4l/ext-ctrls-codec.rst | 32 +++++++++++++++++++
> drivers/media/v4l2-core/v4l2-ctrls.c | 10 ++++++
> include/uapi/linux/v4l2-controls.h | 6 ++++
> 3 files changed, 48 insertions(+)
>
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> index d0d506a444b1..a8b4c0b40747 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -592,6 +592,38 @@ enum v4l2_mpeg_video_bitrate_mode -
> the average video bitrate. It is ignored if the video bitrate mode
> is set to constant bitrate.
>
> +``V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE (enum)``
> +
> +enum v4l2_mpeg_video_frame_skip_mode -
> + Indicates in what conditions the encoder should skip frames. If
> + encoding a frame would cause the encoded stream to be larger then a
> + chosen data limit then the frame will be skipped. Possible values
> + are:
> +
> +
> +.. tabularcolumns:: |p{9.2cm}|p{8.3cm}|
> +
> +.. raw:: latex
> +
> + \small
> +
> +.. flat-table::
> + :header-rows: 0
> + :stub-columns: 0
> +
> + * - ``V4L2_MPEG_FRAME_SKIP_MODE_DISABLED``
> + - Frame skip mode is disabled.
> + * - ``V4L2_MPEG_FRAME_SKIP_MODE_LEVEL_LIMIT``
> + - Frame skip mode enabled and buffer limit is set by the chosen
> + level and is defined by the standard.
> + * - ``V4L2_MPEG_FRAME_SKIP_MODE_BUF_LIMIT``
> + - Frame skip mode enabled and buffer limit is set by the VBV
> + (MPEG1/2/4) or CPB (H264) buffer size control.
> +
> +.. raw:: latex
> +
> + \normalsize
> +
> ``V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION (integer)``
> For every captured frame, skip this many subsequent frames (default
> 0).
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index 3f3fbcd60cc6..d088acfa6dd8 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -590,6 +590,12 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
> "External",
> NULL,
> };
> + static const char * const mpeg_video_frame_skip[] = {
> + "Disabled",
> + "Level Limit",
> + "VBV/CPB Limit",
> + NULL,
> + };
>
> switch (id) {
> case V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ:
> @@ -651,6 +657,8 @@ const char * const *v4l2_ctrl_get_menu(u32 id)
> return flash_strobe_source;
> case V4L2_CID_MPEG_VIDEO_HEADER_MODE:
> return header_mode;
> + case V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE:
> + return mpeg_video_frame_skip;
> case V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE:
> return multi_slice;
> case V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE:
> @@ -844,6 +852,7 @@ const char *v4l2_ctrl_get_name(u32 id)
> case V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE: return "H264 MB Level Rate Control";
> case V4L2_CID_MPEG_VIDEO_HEADER_MODE: return "Sequence Header Mode";
> case V4L2_CID_MPEG_VIDEO_MAX_REF_PIC: return "Max Number of Reference Pics";
> + case V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE: return "Frame Skip Mode";
> case V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP: return "H263 I-Frame QP Value";
> case V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP: return "H263 P-Frame QP Value";
> case V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP: return "H263 B-Frame QP Value";
> @@ -1265,6 +1274,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
> case V4L2_CID_FLASH_LED_MODE:
> case V4L2_CID_FLASH_STROBE_SOURCE:
> case V4L2_CID_MPEG_VIDEO_HEADER_MODE:
> + case V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE:
> case V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE:
> case V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE:
> case V4L2_CID_MPEG_VIDEO_H264_LEVEL:
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index 62271418c1be..4e1526175a4c 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -742,6 +742,12 @@ enum v4l2_cid_mpeg_video_hevc_size_of_length_field {
> #define V4L2_CID_MPEG_VIDEO_HEVC_HIER_CODING_L6_BR (V4L2_CID_MPEG_BASE + 642)
> #define V4L2_CID_MPEG_VIDEO_REF_NUMBER_FOR_PFRAMES (V4L2_CID_MPEG_BASE + 643)
> #define V4L2_CID_MPEG_VIDEO_PREPEND_SPSPPS_TO_IDR (V4L2_CID_MPEG_BASE + 644)
> +#define V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE (V4L2_CID_MPEG_BASE + 645)
I think this now clashes with "media: v4l2-ctrls: Add encoder constant quality control".
I recommend making a new series that combines both series. That avoid this problem.
Regards,
Hans
> +enum v4l2_mpeg_video_frame_skip_mode {
> + V4L2_MPEG_VIDEO_FRAME_SKIP_MODE_DISABLED = 0,
> + V4L2_MPEG_VIDEO_FRAME_SKIP_MODE_LEVEL_LIMIT = 1,
> + V4L2_MPEG_VIDEO_FRAME_SKIP_MODE_BUF_LIMIT = 2,
> +};
>
> /* MPEG-class control IDs specific to the CX2341x driver as defined by V4L2 */
> #define V4L2_CID_MPEG_CX2341X_BASE (V4L2_CTRL_CLASS_MPEG | 0x1000)
>
