On 09/01/2021 07:34, Nuo Mi wrote:
---
  libavcodec/vvc.h | 124 +++++++++++++++++++++++++++++++++++++++++++++++
  1 file changed, 124 insertions(+)
  create mode 100644 libavcodec/vvc.h

diff --git a/libavcodec/vvc.h b/libavcodec/vvc.h
new file mode 100644
index 0000000000..0bd2acac1d
--- /dev/null
+++ b/libavcodec/vvc.h
@@ -0,0 +1,124 @@
...
+
+enum {
+    VVC_MAX_PLANES = 3,

MAX_SAMPLE_ARRAYS, with reference to 6.2?  The term "plane" is never used in 
the specification at all.

+    //7.4.3.3 The value of vps_max_sublayers_minus1 shall be in the range of 0 
to 6, inclusive
+    VVC_MAX_SUBLAYERS = 7,
+
+    // 7.3.2.3: vps_video_parameter_set_id is u(4).
+    VVC_MAX_VPS_COUNT = 16,
+    // 7.3.2.4: sps_seq_parameter_set_id is u(4)
+    VVC_MAX_SPS_COUNT = 16,
+    // 7.3.2.5: pps_pic_parameter_set_id is u(6)
+    VVC_MAX_PPS_COUNT = 64,
+
+    // 7.4.4.1: ptl_num_sub_profiles is u(8)
+    VVC_MAX_SUB_PROFILES = 256,
+
+    // A.4.2: according to (1577), MaxDpbSize is bounded above by 2 * 
maxDpbPicBuf(8)
+    VVC_MAX_DPB_SIZE = 16,
+
+    //7.4.3.4 sps_num_ref_pic_lists in range [0, 64]
+    VVC_MAX_REF_PIC_LISTS = 64,
+
+    //7.4.3.3 sps_num_points_in_qp_table_minus1[i] in range [0, 36 − 
sps_qp_table_start_minus26[i]],
+    //sps_qp_table_start_minus26[i] in range [sps_qp_table_start_minus26[i] 
−26 − QpBdOffset, 36]
+    //for 10 bitsQpBdOffset is 12, so sps_num_points_in_qp_table_minus1[i] in 
range [0, 74]
+    VVC_MAX_POINTS_IN_QP_TABLE = 75,
+
+    // 7.4.6.1: hrd_cpb_cnt_minus1 is in [0, 31].
+    VVC_MAX_CPB_CNT = 32,
+
+    // A.4.1: the highest level allows a MaxLumaPs of 35 651 584.
+    VVC_MAX_LUMA_PS = 35651584,
+    // A.4.1: pic_width_in_luma_samples and pic_height_in_luma_samples are
+    // constrained to be not greater than sqrt(MaxLumaPs * 8).  Hence height/
+    // width are bounded above by sqrt(8 * 35651584) = 16888.2 samples.
+    VVC_MAX_WIDTH  = 16888,
+    VVC_MAX_HEIGHT = 16888,
+
+    // A.4.1: table A.1 allows at most 440 tiles for any au.
+    VVC_MAX_TILE_ROWS    = 440,

Is this bound really the best we can do?

That is, is it actually possible to construct a valid stream with 440 tile 
rows?  It must have a single tile column and a height of at least 14080 (for 
440 rows of 32x32 CTUs), which feels extreme enough that it might hit some of 
the other level constraints.

+    // A.4.1: table A.1 allows at most 20 tile columns for any level.
+    VVC_MAX_TILE_COLUMNS = 20,
+
+    // A.4.1 table A.1 allows at most 600 slice for any level.
+    VVC_MAX_SLICES = 600,
+
+    // 7.4.8: in the worst case (tiles_enabled_flag and
+    // entropy_coding_sync_enabled_flag are both set), entry points can be
+    // placed at the beginning of every Ctb row in every tile, giving an
+    // upper bound of (num_tile_columns_minus1 + 1) * PicHeightInCtbsY - 1.
+    // Only a stream with very high resolution and perverse parameters could
+    // get near that, though, so set a lower limit here with the maximum
+    // possible value for 8K video (at most 135 32x32 Ctb rows).
+    VVC_MAX_ENTRY_POINTS = VVC_MAX_TILE_COLUMNS * 135,
+};
+
+#endif /* AVCODEC_VVC_H */

- Mark
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