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>
---
.../media/v4l/ext-ctrls-codec.rst | 38 +++++++++++++++++++
drivers/media/v4l2-core/v4l2-ctrls.c | 10 +++++
include/uapi/linux/v4l2-controls.h | 6 +++
3 files changed, 54 insertions(+)
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
index b9d3f7ae6486..985e4c2d29bf 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -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
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index bc00d02e411f..eb403858d325 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -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";
@@ -1267,6 +1276,7 @@ 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 0f7e4388dcce..053827cda8e6 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -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)
--
2.17.1
