media: uapi: h264: Clean slice invariants syntax elements

The H.264 specification requires in section 7.4.3 "Slice header semantics",
that the following values shall be the same in all slice headers:

  pic_parameter_set_id
  frame_num
  field_pic_flag
  bottom_field_flag
  idr_pic_id
  pic_order_cnt_lsb
  delta_pic_order_cnt_bottom
  delta_pic_order_cnt[ 0 ]
  delta_pic_order_cnt[ 1 ]
  sp_for_switch_flag
  slice_group_change_cycle

These bitstream fields are part of the slice header, and therefore
passed redundantly on each slice. The purpose of the redundancy
is to make the codec fault-tolerant in network scenarios.

This is of course not needed to be reflected in the V4L2 controls,
given the bitstream has already been parsed by applications.
Therefore, move the redundant fields to the per-frame decode
parameters control (DECODE_PARAMS).

Field 'pic_parameter_set_id' is simply removed in this case,
because the PPS control must currently contain the active PPS.

Syntax elements dec_ref_pic_marking() and those related
to pic order count, remain invariant as well, and therefore,
the fields dec_ref_pic_marking_bit_size and pic_order_cnt_bit_size
are also common to all slices.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

2 files changed, 20 insertions, 20 deletions

diff --git a/include/media/h264-ctrls.h b/include/media/h264-ctrls.h
index e4cae02a765f..0c15ff938873 100644
--- a/include/media/h264-ctrls.h
+++ b/include/media/h264-ctrls.h
@@ -146,10 +146,8 @@ struct v4l2_ctrl_h264_pred_weights {
 #define V4L2_H264_SLICE_TYPE_SP				3
 #define V4L2_H264_SLICE_TYPE_SI				4
 
-#define V4L2_H264_SLICE_FLAG_FIELD_PIC			0x01
-#define V4L2_H264_SLICE_FLAG_BOTTOM_FIELD		0x02
-#define V4L2_H264_SLICE_FLAG_DIRECT_SPATIAL_MV_PRED	0x04
-#define V4L2_H264_SLICE_FLAG_SP_FOR_SWITCH		0x08
+#define V4L2_H264_SLICE_FLAG_DIRECT_SPATIAL_MV_PRED	0x01
+#define V4L2_H264_SLICE_FLAG_SP_FOR_SWITCH		0x02
 
 #define V4L2_H264_TOP_FIELD_REF				0x1
 #define V4L2_H264_BOTTOM_FIELD_REF			0x2
@@ -169,21 +167,8 @@ struct v4l2_ctrl_h264_slice_params {
 	__u32 first_mb_in_slice;
 
 	__u8 slice_type;
-	__u8 pic_parameter_set_id;
 	__u8 colour_plane_id;
 	__u8 redundant_pic_cnt;
-	__u16 frame_num;
-	__u16 idr_pic_id;
-	__u16 pic_order_cnt_lsb;
-	__s32 delta_pic_order_cnt_bottom;
-	__s32 delta_pic_order_cnt0;
-	__s32 delta_pic_order_cnt1;
-
-	/* Size in bits of dec_ref_pic_marking() syntax element. */
-	__u32 dec_ref_pic_marking_bit_size;
-	/* Size in bits of pic order count syntax. */
-	__u32 pic_order_cnt_bit_size;
-
 	__u8 cabac_init_idc;
 	__s8 slice_qp_delta;
 	__s8 slice_qs_delta;
@@ -192,7 +177,8 @@ struct v4l2_ctrl_h264_slice_params {
 	__s8 slice_beta_offset_div2;
 	__u8 num_ref_idx_l0_active_minus1;
 	__u8 num_ref_idx_l1_active_minus1;
-	__u32 slice_group_change_cycle;
+
+	__u8 reserved;
 
 	struct v4l2_h264_reference ref_pic_list0[V4L2_H264_REF_LIST_LEN];
 	struct v4l2_h264_reference ref_pic_list1[V4L2_H264_REF_LIST_LEN];
@@ -217,13 +203,28 @@ struct v4l2_h264_dpb_entry {
 	__u32 flags; /* V4L2_H264_DPB_ENTRY_FLAG_* */
 };
 
-#define V4L2_H264_DECODE_PARAM_FLAG_IDR_PIC	0x01
+#define V4L2_H264_DECODE_PARAM_FLAG_IDR_PIC		0x01
+#define V4L2_H264_DECODE_PARAM_FLAG_FIELD_PIC		0x02
+#define V4L2_H264_DECODE_PARAM_FLAG_BOTTOM_FIELD	0x04
 
 struct v4l2_ctrl_h264_decode_params {
 	struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES];
 	__u16 nal_ref_idc;
+	__u16 frame_num;
 	__s32 top_field_order_cnt;
 	__s32 bottom_field_order_cnt;
+	__u16 idr_pic_id;
+	__u16 pic_order_cnt_lsb;
+	__s32 delta_pic_order_cnt_bottom;
+	__s32 delta_pic_order_cnt0;
+	__s32 delta_pic_order_cnt1;
+	/* Size in bits of dec_ref_pic_marking() syntax element. */
+	__u32 dec_ref_pic_marking_bit_size;
+	/* Size in bits of pic order count syntax. */
+	__u32 pic_order_cnt_bit_size;
+	__u32 slice_group_change_cycle;
+
+	__u32 reserved;
 	__u32 flags; /* V4L2_H264_DECODE_PARAM_FLAG_* */
 };
 
diff --git a/include/media/v4l2-h264.h b/include/media/v4l2-h264.h
index 1a5f26fc2a9a..f08ba181263d 100644
--- a/include/media/v4l2-h264.h
+++ b/include/media/v4l2-h264.h
@@ -44,7 +44,6 @@ struct v4l2_h264_reflist_builder {
 void
 v4l2_h264_init_reflist_builder(struct v4l2_h264_reflist_builder *b,
 		const struct v4l2_ctrl_h264_decode_params *dec_params,
-		const struct v4l2_ctrl_h264_slice_params *slice_params,
 		const struct v4l2_ctrl_h264_sps *sps,
 		const struct v4l2_h264_dpb_entry dpb[V4L2_H264_NUM_DPB_ENTRIES]);