media: uapi: mpeg2: Split sequence and picture parameters

Typically, bitstreams are composed of a sequence header,
followed by a number of picture header and picture coding extension
headers. Each picture can be composed of a number of slices.

Let's split the MPEG-2 uAPI to follow these semantics more closely,
allowing more usage flexibility. Having these controls split up
allows applications to set a sequence control at the beginning
of a sequence, and then set a picture control for each frame.

While here add padding fields where needed, and document
the uAPI header thoroughly.

Note that the V4L2_CTRL_TYPE_{} defines had to be moved because
it clashes with existing ones. This is not really an issue
since they will be re-defined when the controls are moved
out of staging.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Tested-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Jernej Skrabec <jernej.skrabec@siol.net>
Tested-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

1 files changed, 44 insertions, 12 deletions

diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 37531302dd3a..59b16f70b093 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -977,6 +977,8 @@ const char *v4l2_ctrl_get_name(u32 id)
 	case V4L2_CID_MPEG_VIDEO_LTR_COUNT:			return "LTR Count";
 	case V4L2_CID_MPEG_VIDEO_FRAME_LTR_INDEX:		return "Frame LTR Index";
 	case V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES:		return "Use LTR Frames";
+	case V4L2_CID_MPEG_VIDEO_MPEG2_SEQUENCE:		return "MPEG-2 Sequence Header";
+	case V4L2_CID_MPEG_VIDEO_MPEG2_PICTURE:			return "MPEG-2 Picture Header";
 	case V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS:		return "MPEG-2 Slice Parameters";
 	case V4L2_CID_MPEG_VIDEO_MPEG2_QUANTISATION:		return "MPEG-2 Quantisation Matrices";
 	case V4L2_CID_FWHT_I_FRAME_QP:				return "FWHT I-Frame QP Value";
@@ -1499,6 +1501,12 @@ 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_SEQUENCE:
+		*type = V4L2_CTRL_TYPE_MPEG2_SEQUENCE;
+		break;
+	case V4L2_CID_MPEG_VIDEO_MPEG2_PICTURE:
+		*type = V4L2_CTRL_TYPE_MPEG2_PICTURE;
+		break;
 	case V4L2_CID_MPEG_VIDEO_MPEG2_SLICE_PARAMS:
 		*type = V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS;
 		break;
@@ -1703,7 +1711,8 @@ static bool std_equal(const struct v4l2_ctrl *ctrl, u32 idx,
 static void std_init_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 			      union v4l2_ctrl_ptr ptr)
 {
-	struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
+	struct v4l2_ctrl_mpeg2_sequence *p_mpeg2_sequence;
+	struct v4l2_ctrl_mpeg2_picture *p_mpeg2_picture;
 	struct v4l2_ctrl_mpeg2_quantisation *p_mpeg2_quant;
 	struct v4l2_ctrl_vp8_frame *p_vp8_frame;
 	struct v4l2_ctrl_fwht_params *p_fwht_params;
@@ -1720,13 +1729,18 @@ static void std_init_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 	 * v4l2_ctrl_type enum.
 	 */
 	switch ((u32)ctrl->type) {
-	case V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS:
-		p_mpeg2_slice_params = p;
+	case V4L2_CTRL_TYPE_MPEG2_SEQUENCE:
+		p_mpeg2_sequence = p;
+
 		/* 4:2:0 */
-		p_mpeg2_slice_params->sequence.chroma_format = 1;
+		p_mpeg2_sequence->chroma_format = 1;
+		break;
+	case V4L2_CTRL_TYPE_MPEG2_PICTURE:
+		p_mpeg2_picture = p;
+
 		/* interlaced top field */
-		p_mpeg2_slice_params->picture.picture_structure = 1;
-		p_mpeg2_slice_params->picture.picture_coding_type =
+		p_mpeg2_picture->picture_structure = V4L2_MPEG2_PIC_TOP_FIELD;
+		p_mpeg2_picture->picture_coding_type =
 					V4L2_MPEG2_PIC_CODING_TYPE_I;
 		break;
 	case V4L2_CTRL_TYPE_MPEG2_QUANTISATION:
@@ -1909,6 +1923,8 @@ static void std_log(const struct v4l2_ctrl *ctrl)
 static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 				 union v4l2_ctrl_ptr ptr)
 {
+	struct v4l2_ctrl_mpeg2_sequence *p_mpeg2_sequence;
+	struct v4l2_ctrl_mpeg2_picture *p_mpeg2_picture;
 	struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
 	struct v4l2_ctrl_vp8_frame *p_vp8_frame;
 	struct v4l2_ctrl_fwht_params *p_fwht_params;
@@ -1926,10 +1942,10 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 	unsigned int i;
 
 	switch ((u32)ctrl->type) {
-	case V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS:
-		p_mpeg2_slice_params = p;
+	case V4L2_CTRL_TYPE_MPEG2_SEQUENCE:
+		p_mpeg2_sequence = p;
 
-		switch (p_mpeg2_slice_params->sequence.chroma_format) {
+		switch (p_mpeg2_sequence->chroma_format) {
 		case 1: /* 4:2:0 */
 		case 2: /* 4:2:2 */
 		case 3: /* 4:4:4 */
@@ -1937,8 +1953,12 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 		default:
 			return -EINVAL;
 		}
+		break;
+
+	case V4L2_CTRL_TYPE_MPEG2_PICTURE:
+		p_mpeg2_picture = p;
 
-		switch (p_mpeg2_slice_params->picture.intra_dc_precision) {
+		switch (p_mpeg2_picture->intra_dc_precision) {
 		case 0: /* 8 bits */
 		case 1: /* 9 bits */
 		case 2: /* 10 bits */
@@ -1948,7 +1968,7 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 			return -EINVAL;
 		}
 
-		switch (p_mpeg2_slice_params->picture.picture_structure) {
+		switch (p_mpeg2_picture->picture_structure) {
 		case V4L2_MPEG2_PIC_TOP_FIELD:
 		case V4L2_MPEG2_PIC_BOTTOM_FIELD:
 		case V4L2_MPEG2_PIC_FRAME:
@@ -1957,7 +1977,7 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 			return -EINVAL;
 		}
 
-		switch (p_mpeg2_slice_params->picture.picture_coding_type) {
+		switch (p_mpeg2_picture->picture_coding_type) {
 		case V4L2_MPEG2_PIC_CODING_TYPE_I:
 		case V4L2_MPEG2_PIC_CODING_TYPE_P:
 		case V4L2_MPEG2_PIC_CODING_TYPE_B:
@@ -1965,7 +1985,13 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
 		default:
 			return -EINVAL;
 		}
+		zero_reserved(*p_mpeg2_picture);
+		break;
 
+	case V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS:
+		p_mpeg2_slice_params = p;
+
+		zero_reserved(*p_mpeg2_slice_params);
 		break;
 
 	case V4L2_CTRL_TYPE_MPEG2_QUANTISATION:
@@ -2934,6 +2960,12 @@ 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_SEQUENCE:
+		elem_size = sizeof(struct v4l2_ctrl_mpeg2_sequence);
+		break;
+	case V4L2_CTRL_TYPE_MPEG2_PICTURE:
+		elem_size = sizeof(struct v4l2_ctrl_mpeg2_picture);
+		break;
 	case V4L2_CTRL_TYPE_MPEG2_SLICE_PARAMS:
 		elem_size = sizeof(struct v4l2_ctrl_mpeg2_slice_params);
 		break;