[PATCH v3 08/14] media: v4l: Add definitions for MPEG2 frame format and header metadata

From: Paul Kocialkowski
Date: Mon May 07 2018 - 08:48:08 EST

From: Florent Revest <florent.revest@xxxxxxxxxxxxxxxxxx>

Stateless video decoding engines require both the MPEG slices and
associated metadata from the video stream in order to decode frames.

This introduces definitions for a new pixel format, describing buffers
with MPEG2 slice data, as well as a control structure for passing the
frame header (metadata) to drivers.

Signed-off-by: Florent Revest <florent.revest@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-ctrls.c | 10 ++++++++++
drivers/media/v4l2-core/v4l2-ioctl.c | 1 +
include/uapi/linux/v4l2-controls.h | 26 ++++++++++++++++++++++++++
include/uapi/linux/videodev2.h | 3 +++
4 files changed, 40 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index df58a23eb731..cdf860c8e3d8 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -826,6 +826,7 @@ 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_MPEG2_FRAME_HDR: return "MPEG2 Frame Header";

/* VPX controls */
case V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS: return "VPX Number of Partitions";
@@ -1271,6 +1272,9 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
case V4L2_CID_RDS_TX_ALT_FREQS:
*type = V4L2_CTRL_TYPE_U32;
break;
+ case V4L2_CID_MPEG_VIDEO_MPEG2_FRAME_HDR:
+ *type = V4L2_CTRL_TYPE_MPEG2_FRAME_HDR;
+ break;
default:
*type = V4L2_CTRL_TYPE_INTEGER;
break;
@@ -1591,6 +1595,9 @@ static int std_validate(const struct v4l2_ctrl *ctrl, u32 idx,
return -ERANGE;
return 0;

+ case V4L2_CTRL_TYPE_MPEG2_FRAME_HDR:
+ return 0;
+
default:
return -EINVAL;
}
@@ -2165,6 +2172,9 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
case V4L2_CTRL_TYPE_U32:
elem_size = sizeof(u32);
break;
+ case V4L2_CTRL_TYPE_MPEG2_FRAME_HDR:
+ elem_size = sizeof(struct v4l2_ctrl_mpeg2_frame_hdr);
+ break;
default:
if (type < V4L2_CTRL_COMPOUND_TYPES)
elem_size = sizeof(s32);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 561a1fe3160b..38d318c47c55 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1274,6 +1274,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
case V4L2_PIX_FMT_VP8: descr = "VP8"; break;
case V4L2_PIX_FMT_VP9: descr = "VP9"; break;
case V4L2_PIX_FMT_HEVC: descr = "HEVC"; break; /* aka H.265 */
+ case V4L2_PIX_FMT_MPEG2_FRAME: descr = "MPEG2 Frame"; break;
case V4L2_PIX_FMT_CPIA1: descr = "GSPCA CPiA YUV"; break;
case V4L2_PIX_FMT_WNVA: descr = "WNVA"; break;
case V4L2_PIX_FMT_SN9C10X: descr = "GSPCA SN9C10X"; break;
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 8d473c979b61..23da8bfa7e6f 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -557,6 +557,8 @@ enum v4l2_mpeg_video_mpeg4_profile {
};
#define V4L2_CID_MPEG_VIDEO_MPEG4_QPEL (V4L2_CID_MPEG_BASE+407)

+#define V4L2_CID_MPEG_VIDEO_MPEG2_FRAME_HDR (V4L2_CID_MPEG_BASE+450)
+
/* Control IDs for VP8 streams
* Although VP8 is not part of MPEG we add these controls to the MPEG class
* as that class is already handling other video compression standards
@@ -1076,4 +1078,28 @@ enum v4l2_detect_md_mode {
#define V4L2_CID_DETECT_MD_THRESHOLD_GRID (V4L2_CID_DETECT_CLASS_BASE + 3)
#define V4L2_CID_DETECT_MD_REGION_GRID (V4L2_CID_DETECT_CLASS_BASE + 4)

+struct v4l2_ctrl_mpeg2_frame_hdr {
+ __u32 slice_len;
+ __u32 slice_pos;
+ enum { MPEG1, MPEG2 } type;
+
+ __u16 width;
+ __u16 height;
+
+ enum { PCT_I = 1, PCT_P, PCT_B, PCT_D } picture_coding_type;
+ __u8 f_code[2][2];
+
+ __u8 intra_dc_precision;
+ __u8 picture_structure;
+ __u8 top_field_first;
+ __u8 frame_pred_frame_dct;
+ __u8 concealment_motion_vectors;
+ __u8 q_scale_type;
+ __u8 intra_vlc_format;
+ __u8 alternate_scan;
+
+ __u8 backward_ref_index;
+ __u8 forward_ref_index;
+};
+
#endif
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 1f6c4b52baae..d8f9b59d90d7 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -636,6 +636,7 @@ struct v4l2_pix_format {
#define V4L2_PIX_FMT_VP8 v4l2_fourcc('V', 'P', '8', '0') /* VP8 */
#define V4L2_PIX_FMT_VP9 v4l2_fourcc('V', 'P', '9', '0') /* VP9 */
#define V4L2_PIX_FMT_HEVC v4l2_fourcc('H', 'E', 'V', 'C') /* HEVC aka H.265 */
+#define V4L2_PIX_FMT_MPEG2_FRAME v4l2_fourcc('M', 'G', '2', 'F') /* MPEG2 frame */

/* Vendor-specific formats */
#define V4L2_PIX_FMT_CPIA1 v4l2_fourcc('C', 'P', 'I', 'A') /* cpia1 YUV */
@@ -1587,6 +1588,7 @@ struct v4l2_ext_control {
__u8 __user *p_u8;
__u16 __user *p_u16;
__u32 __user *p_u32;
+ struct v4l2_ctrl_mpeg2_frame_hdr __user *p_mpeg2_frame_hdr;
void __user *ptr;
};
} __attribute__ ((packed));
@@ -1632,6 +1634,7 @@ enum v4l2_ctrl_type {
V4L2_CTRL_TYPE_U8 = 0x0100,
V4L2_CTRL_TYPE_U16 = 0x0101,
V4L2_CTRL_TYPE_U32 = 0x0102,
+ V4L2_CTRL_TYPE_MPEG2_FRAME_HDR = 0x0109,
};

/* Used in the VIDIOC_QUERYCTRL ioctl for querying controls */
--
2.16.3