media: v4l2-ctrls: Add intra-refresh period control

Add a control to set intra-refresh period.

Acked-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Author: Stanimir Varbanov

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

@@ -1175,9 +1175,24 @@ enum v4l2_mpeg_video_h264_entropy_mode -
     macroblocks refreshed every frame. Each frame a successive set of
     macroblocks is refreshed until the cycle completes and starts from
     the top of the frame. Setting this control to zero means that
-    macroblocks will not be refreshed.
+    macroblocks will not be refreshed.  Note that this control will not
+    take effect when ``V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD`` control
+    is set to non zero value.
     Applicable to H264, H263 and MPEG4 encoder.
 
+``V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD (integer)``
+    Intra macroblock refresh period. This sets the period to refresh
+    the whole frame. In other words, this defines the number of frames
+    for which the whole frame will be intra-refreshed.  An example:
+    setting period to 1 means that the whole frame will be refreshed,
+    setting period to 2 means that the half of macroblocks will be
+    intra-refreshed on frameX and the other half of macroblocks
+    will be refreshed in frameX + 1 and so on. Setting the period to
+    zero means no period is specified.
+    Note that if the client sets this control to non zero value the
+    ``V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB`` control shall be
+    ignored. Applicable to H264 and HEVC encoders.
+
 ``V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE (boolean)``
     Frame level rate control enable. If this control is disabled then
     the quantization parameter for each frame type is constant and set

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

@@ -833,6 +833,7 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE:	return "Decoder Slice Interface";
 	case V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER:	return "MPEG4 Loop Filter Enable";
 	case V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB:	return "Number of Intra Refresh MBs";
+	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD:		return "Intra Refresh Period";
 	case V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE:		return "Frame Level Rate Control Enable";
 	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";
@@ -1258,6 +1259,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
 	case V4L2_CID_MPEG_VIDEO_MV_H_SEARCH_RANGE:
 	case V4L2_CID_MPEG_VIDEO_MV_V_SEARCH_RANGE:
 	case V4L2_CID_MPEG_VIDEO_DEC_DISPLAY_DELAY:
+	case V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD:
 		*type = V4L2_CTRL_TYPE_INTEGER;
 		break;
 	case V4L2_CID_MPEG_VIDEO_LTR_COUNT:

include/uapi/linux/v4l2-controls.h

@@ -435,6 +435,7 @@ enum v4l2_mpeg_video_multi_slice_mode {
 #define V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX		(V4L2_CID_CODEC_BASE+233)
 #define V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES		(V4L2_CID_CODEC_BASE+234)
 #define V4L2_CID_MPEG_VIDEO_DEC_CONCEAL_COLOR		(V4L2_CID_CODEC_BASE+235)
+#define V4L2_CID_MPEG_VIDEO_INTRA_REFRESH_PERIOD	(V4L2_CID_CODEC_BASE+236)
 
 /* CIDs for the MPEG-2 Part 2 (H.262) codec */
 #define V4L2_CID_MPEG_VIDEO_MPEG2_LEVEL			(V4L2_CID_CODEC_BASE+270)