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>

1 files changed, 43 insertions, 43 deletions

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
index 304b6012b358..4cd9fd9c5a89 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -1767,43 +1767,11 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
       - ``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``
-      -
-    * - struct :c:type:`v4l2_h264_pred_weight_table`
-      - ``pred_weight_table``
-      -
-    * - __u32
-      - ``dec_ref_pic_marking_bit_size``
-      - Size in bits of the dec_ref_pic_marking() syntax element.
-    * - __u32
-      - ``pic_order_cnt_bit_size``
-      - Combined size in bits of the picture order count related syntax
-        elements: pic_order_cnt_lsb, delta_pic_order_cnt_bottom,
-        delta_pic_order_cnt0, and delta_pic_order_cnt1.
     * - __u8
       - ``cabac_init_idc``
       -
@@ -1830,9 +1798,9 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
       - ``num_ref_idx_l1_active_minus1``
       - If num_ref_idx_active_override_flag is not set, this field must be
         set to the value of num_ref_idx_l1_default_active_minus1.
-    * - __u32
-      - ``slice_group_change_cycle``
-      -
+    * - __u8
+      - ``reserved``
+      - Applications and drivers must set this to zero.
     * - struct :c:type:`v4l2_h264_reference`
       - ``ref_pic_list0[32]``
       - Reference picture list after applying the per-slice modifications
@@ -1854,17 +1822,11 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
     :stub-columns: 0
     :widths:       1 1 2
 
-    * - ``V4L2_H264_SLICE_FLAG_FIELD_PIC``
-      - 0x00000001
-      -
-    * - ``V4L2_H264_SLICE_FLAG_BOTTOM_FIELD``
-      - 0x00000002
-      -
     * - ``V4L2_H264_SLICE_FLAG_DIRECT_SPATIAL_MV_PRED``
-      - 0x00000004
+      - 0x00000001
       -
     * - ``V4L2_H264_SLICE_FLAG_SP_FOR_SWITCH``
-      - 0x00000008
+      - 0x00000002
       -
 
 ``V4L2_CID_MPEG_VIDEO_H264_PRED_WEIGHTS (struct)``
@@ -1990,12 +1952,44 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
     * - __u16
       - ``nal_ref_idc``
       - NAL reference ID value coming from the NAL Unit header
+    * - __u16
+      - ``frame_num``
+      -
     * - __s32
       - ``top_field_order_cnt``
       - Picture Order Count for the coded top field
     * - __s32
       - ``bottom_field_order_cnt``
       - Picture Order Count for the coded bottom field
+    * - __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``
+      -
+    * - __u32
+      - ``dec_ref_pic_marking_bit_size``
+      - Size in bits of the dec_ref_pic_marking() syntax element.
+    * - __u32
+      - ``pic_order_cnt_bit_size``
+      - Combined size in bits of the picture order count related syntax
+        elements: pic_order_cnt_lsb, delta_pic_order_cnt_bottom,
+        delta_pic_order_cnt0, and delta_pic_order_cnt1.
+    * - __u32
+      - ``slice_group_change_cycle``
+      -
+    * - __u32
+      - ``reserved``
+      - Applications and drivers must set this to zero.
     * - __u32
       - ``flags``
       - See :ref:`Decode Parameters Flags <h264_decode_params_flags>`
@@ -2014,6 +2008,12 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
     * - ``V4L2_H264_DECODE_PARAM_FLAG_IDR_PIC``
       - 0x00000001
       - That picture is an IDR picture
+    * - ``V4L2_H264_DECODE_PARAM_FLAG_FIELD_PIC``
+      - 0x00000002
+      -
+    * - ``V4L2_H264_DECODE_PARAM_FLAG_BOTTOM_FIELD``
+      - 0x00000004
+      -
 
 .. c:type:: v4l2_h264_dpb_entry