How about we define it as 20, check the size and return error if > 20. 20 should enough for most of clips. hevc used 20.
On Sun, Jan 10, 2021 at 9:39 AM Nuo Mi <nuomi2...@gmail.com> wrote: > > > On Sun, Jan 10, 2021 at 3:09 AM Mark Thompson <s...@jkqxz.net> wrote: > >> 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. >> > The VVC_MAX_HEIGHT is 16888, it's higher than 14080. > If we limit the VVC_MAX_HEIGHT to 4k, we can reduce it to 135. > >> >> > + // 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 >> _______________________________________________ >> ffmpeg-devel mailing list >> ffmpeg-devel@ffmpeg.org >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel >> >> To unsubscribe, visit link above, or email >> ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > > _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".