media: v4l2-ctrl: Add frame-skip std encoder control (44f5b2ff) · Commits · 戴 / test

Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst

+38 −0

Original line number	Diff line number	Diff line
		@@ -602,6 +602,40 @@ enum v4l2_mpeg_video_bitrate_mode -
		Encoder will decide the appropriate quantization parameter and
		bitrate to produce requested frame quality.


		``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
		:ref:`VBV (MPEG1/2/4) <v4l2-mpeg-video-vbv-size>` or
		:ref:`CPB (H264) buffer size <v4l2-mpeg-video-h264-cpb-size>` control.

		.. raw:: latex

		\normalsize

		``V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION (integer)``
		For every captured frame, skip this many subsequent frames (default
		0).
		@@ -1173,6 +1207,8 @@ enum v4l2_mpeg_video_h264_entropy_mode -
		Quantization parameter for an B frame for MPEG4. Valid range: from 1
		to 31.

		.. _v4l2-mpeg-video-vbv-size:

		``V4L2_CID_MPEG_VIDEO_VBV_SIZE (integer)``
		The Video Buffer Verifier size in kilobytes, it is used as a
		limitation of frame skip. The VBV is defined in the standard as a
		@@ -1210,6 +1246,8 @@ enum v4l2_mpeg_video_h264_entropy_mode -
		Force a key frame for the next queued buffer. Applicable to
		encoders. This is a general, codec-agnostic keyframe control.

		.. _v4l2-mpeg-video-h264-cpb-size:

		``V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE (integer)``
		The Coded Picture Buffer size in kilobytes, it is used as a
		limitation of frame skip. The CPB is defined in the H264 standard as

drivers/media/v4l2-core/v4l2-ctrls.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -591,6 +591,12 @@ 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:
		@@ -652,6 +658,8 @@ 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:
		@@ -846,6 +854,7 @@ 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";
		@@ -1268,6 +1277,7 @@ 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:

include/uapi/linux/v4l2-controls.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -744,6 +744,12 @@ enum v4l2_cid_mpeg_video_hevc_size_of_length_field {
		#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_CONSTANT_QUALITY (V4L2_CID_MPEG_BASE + 645)
		#define V4L2_CID_MPEG_VIDEO_FRAME_SKIP_MODE (V4L2_CID_MPEG_BASE + 646)
		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)

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