text: /*
   * H.26L/H.264/AVC/JVT/14496-10/... parameter set decoding
   * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  /**
   * @file
   * H.264 / AVC / MPEG-4 part10 parameter set decoding.
   * @author Michael Niedermayer <michaelni@gmx.at>
   */
  
  #include <inttypes.h>
  
  #include "libavutil/imgutils.h"
  #include "internal.h"
  #include "mathops.h"
  #include "avcodec.h"
  #include "h264data.h"
  #include "h264_ps.h"
  #include "golomb.h"
  
  #define MAX_LOG2_MAX_FRAME_NUM    (12 + 4)
  #define MIN_LOG2_MAX_FRAME_NUM    4
  
  #define EXTENDED_SAR       255
  
  static const uint8_t default_scaling4[2][16] = {
      {  6, 13, 20, 28, 13, 20, 28, 32,
        20, 28, 32, 37, 28, 32, 37, 42 },
      { 10, 14, 20, 24, 14, 20, 24, 27,
        20, 24, 27, 30, 24, 27, 30, 34 }
  };
  
  static const uint8_t default_scaling8[2][64] = {
      {  6, 10, 13, 16, 18, 23, 25, 27,
        10, 11, 16, 18, 23, 25, 27, 29,
        13, 16, 18, 23, 25, 27, 29, 31,
        16, 18, 23, 25, 27, 29, 31, 33,
        18, 23, 25, 27, 29, 31, 33, 36,
        23, 25, 27, 29, 31, 33, 36, 38,
        25, 27, 29, 31, 33, 36, 38, 40,
        27, 29, 31, 33, 36, 38, 40, 42 },
      {  9, 13, 15, 17, 19, 21, 22, 24,
        13, 13, 17, 19, 21, 22, 24, 25,
        15, 17, 19, 21, 22, 24, 25, 27,
        17, 19, 21, 22, 24, 25, 27, 28,
        19, 21, 22, 24, 25, 27, 28, 30,
        21, 22, 24, 25, 27, 28, 30, 32,
        22, 24, 25, 27, 28, 30, 32, 33,
        24, 25, 27, 28, 30, 32, 33, 35 }
  };
  
  /* maximum number of MBs in the DPB for a given level */
  static const int level_max_dpb_mbs[][2] = {
      { 10, 396       },
      { 11, 900       },
      { 12, 2376      },
      { 13, 2376      },
      { 20, 2376      },
      { 21, 4752      },
      { 22, 8100      },
      { 30, 8100      },
      { 31, 18000     },
      { 32, 20480     },
      { 40, 32768     },
      { 41, 32768     },
      { 42, 34816     },
      { 50, 110400    },
      { 51, 184320    },
      { 52, 184320    },
  };
  
  static void remove_pps(H264ParamSets *s, int id)
  {
      av_buffer_unref(&s->pps_list[id]);
  }
  
  static void remove_sps(H264ParamSets *s, int id)
  {
  #if 0
      int i;
      if (s->sps_list[id]) {
          /* drop all PPS that depend on this SPS */
          for (i = 0; i < FF_ARRAY_ELEMS(s->pps_list); i++)
              if (s->pps_list[i] && ((PPS*)s->pps_list[i]->data)->sps_id == id)
                  remove_pps(s, i);
      }
  #endif
      av_buffer_unref(&s->sps_list[id]);
  }
  
  static inline int decode_hrd_parameters(GetBitContext *gb, AVCodecContext *avctx,
                                          SPS *sps)
  {
      int cpb_count, i;
      cpb_count = get_ue_golomb_31(gb) + 1;
  
      if (cpb_count > 32U) {
          av_log(avctx, AV_LOG_ERROR, "cpb_count %d invalid\n", cpb_count);
          return AVERROR_INVALIDDATA;
      }
  
      get_bits(gb, 4); /* bit_rate_scale */
      get_bits(gb, 4); /* cpb_size_scale */
      for (i = 0; i < cpb_count; i++) {
          get_ue_golomb_long(gb); /* bit_rate_value_minus1 */
          get_ue_golomb_long(gb); /* cpb_size_value_minus1 */
          get_bits1(gb);          /* cbr_flag */
      }
      sps->initial_cpb_removal_delay_length = get_bits(gb, 5) + 1;
      sps->cpb_removal_delay_length         = get_bits(gb, 5) + 1;
      sps->dpb_output_delay_length          = get_bits(gb, 5) + 1;
      sps->time_offset_length               = get_bits(gb, 5);
      sps->cpb_cnt                          = cpb_count;
      return 0;
  }
  
  static inline int decode_vui_parameters(GetBitContext *gb, AVCodecContext *avctx,
                                          SPS *sps)
  {
      int aspect_ratio_info_present_flag;
      unsigned int aspect_ratio_idc;
  
      aspect_ratio_info_present_flag = get_bits1(gb);
  
      if (aspect_ratio_info_present_flag) {
          aspect_ratio_idc = get_bits(gb, 8);
          if (aspect_ratio_idc == EXTENDED_SAR) {
              sps->sar.num = get_bits(gb, 16);
              sps->sar.den = get_bits(gb, 16);
          } else if (aspect_ratio_idc < FF_ARRAY_ELEMS(ff_h264_pixel_aspect)) {
              sps->sar = ff_h264_pixel_aspect[aspect_ratio_idc];
          } else {
              av_log(avctx, AV_LOG_ERROR, "illegal aspect ratio\n");
              return AVERROR_INVALIDDATA;
          }
      } else {
          sps->sar.num =
          sps->sar.den = 0;
      }
  
      if (get_bits1(gb))      /* overscan_info_present_flag */
          get_bits1(gb);      /* overscan_appropriate_flag */
  
      sps->video_signal_type_present_flag = get_bits1(gb);
      if (sps->video_signal_type_present_flag) {
          get_bits(gb, 3);                 /* video_format */
          sps->full_range = get_bits1(gb); /* video_full_range_flag */
  
          sps->colour_description_present_flag = get_bits1(gb);
          if (sps->colour_description_present_flag) {
              sps->color_primaries = get_bits(gb, 8); /* colour_primaries */
              sps->color_trc       = get_bits(gb, 8); /* transfer_characteristics */
              sps->colorspace      = get_bits(gb, 8); /* matrix_coefficients */
  
              // Set invalid values to "unspecified"
              if (!av_color_primaries_name(sps->color_primaries))
                  sps->color_primaries = AVCOL_PRI_UNSPECIFIED;
              if (!av_color_transfer_name(sps->color_trc))
                  sps->color_trc = AVCOL_TRC_UNSPECIFIED;
              if (!av_color_space_name(sps->colorspace))
                  sps->colorspace = AVCOL_SPC_UNSPECIFIED;
          }
      }
  
      /* chroma_location_info_present_flag */
      if (get_bits1(gb)) {
          /* chroma_sample_location_type_top_field */
          avctx->chroma_sample_location = get_ue_golomb(gb) + 1;
          get_ue_golomb(gb);  /* chroma_sample_location_type_bottom_field */
      }
  
      if (show_bits1(gb) && get_bits_left(gb) < 10) {
          av_log(avctx, AV_LOG_WARNING, "Truncated VUI\n");
          return 0;
      }
  
      sps->timing_info_present_flag = get_bits1(gb);
      if (sps->timing_info_present_flag) {
          unsigned num_units_in_tick = get_bits_long(gb, 32);
          unsigned time_scale        = get_bits_long(gb, 32);
          if (!num_units_in_tick || !time_scale) {
              av_log(avctx, AV_LOG_ERROR,
                     "time_scale/num_units_in_tick invalid or unsupported (%u/%u)\n",
                     time_scale, num_units_in_tick);
              sps->timing_info_present_flag = 0;
          } else {
              sps->num_units_in_tick = num_units_in_tick;
              sps->time_scale = time_scale;
          }
          sps->fixed_frame_rate_flag = get_bits1(gb);
      }
  
      sps->nal_hrd_parameters_present_flag = get_bits1(gb);
      if (sps->nal_hrd_parameters_present_flag)
          if (decode_hrd_parameters(gb, avctx, sps) < 0)
              return AVERROR_INVALIDDATA;
      sps->vcl_hrd_parameters_present_flag = get_bits1(gb);
      if (sps->vcl_hrd_parameters_present_flag)
          if (decode_hrd_parameters(gb, avctx, sps) < 0)
              return AVERROR_INVALIDDATA;
      if (sps->nal_hrd_parameters_present_flag ||
          sps->vcl_hrd_parameters_present_flag)
          get_bits1(gb);     /* low_delay_hrd_flag */
      sps->pic_struct_present_flag = get_bits1(gb);
      if (!get_bits_left(gb))
          return 0;
      sps->bitstream_restriction_flag = get_bits1(gb);
      if (sps->bitstream_restriction_flag) {
          get_bits1(gb);     /* motion_vectors_over_pic_boundaries_flag */
          get_ue_golomb(gb); /* max_bytes_per_pic_denom */
          get_ue_golomb(gb); /* max_bits_per_mb_denom */
          get_ue_golomb(gb); /* log2_max_mv_length_horizontal */
          get_ue_golomb(gb); /* log2_max_mv_length_vertical */
          sps->num_reorder_frames = get_ue_golomb(gb);
          get_ue_golomb(gb); /*max_dec_frame_buffering*/
  
          if (get_bits_left(gb) < 0) {
              sps->num_reorder_frames         = 0;
              sps->bitstream_restriction_flag = 0;
          }
  
          if (sps->num_reorder_frames > 16U
              /* max_dec_frame_buffering || max_dec_frame_buffering > 16 */) {
              av_log(avctx, AV_LOG_ERROR,
                     "Clipping illegal num_reorder_frames %d\n",
                     sps->num_reorder_frames);
              sps->num_reorder_frames = 16;
              return AVERROR_INVALIDDATA;
          }
      }
  
      return 0;
  }
  
  static int decode_scaling_list(GetBitContext *gb, uint8_t *factors, int size,
                                  const uint8_t *jvt_list,
                                  const uint8_t *fallback_list)
  {
      int i, last = 8, next = 8;
      const uint8_t *scan = size == 16 ? ff_zigzag_scan : ff_zigzag_direct;
      if (!get_bits1(gb)) /* matrix not written, we use the predicted one */
          memcpy(factors, fallback_list, size * sizeof(uint8_t));
      else
          for (i = 0; i < size; i++) {
              if (next) {
                  int v = get_se_golomb(gb);
                  if (v < -128 || v > 127) {
                      av_log(NULL, AV_LOG_ERROR, "delta scale %d is invalid\n", v);
                      return AVERROR_INVALIDDATA;
                  }
                  next = (last + v) & 0xff;
              }
              if (!i && !next) { /* matrix not written, we use the preset one */
                  memcpy(factors, jvt_list, size * sizeof(uint8_t));
                  break;
              }
              last = factors[scan[i]] = next ? next : last;
          }
      return 0;
  }
  
  /* returns non zero if the provided SPS scaling matrix has been filled */
  static int decode_scaling_matrices(GetBitContext *gb, const SPS *sps,
                                      const PPS *pps, int is_sps,
                                      uint8_t(*scaling_matrix4)[16],
                                      uint8_t(*scaling_matrix8)[64])
  {
      int fallback_sps = !is_sps && sps->scaling_matrix_present;
      const uint8_t *fallback[4] = {
          fallback_sps ? sps->scaling_matrix4[0] : default_scaling4[0],
          fallback_sps ? sps->scaling_matrix4[3] : default_scaling4[1],
          fallback_sps ? sps->scaling_matrix8[0] : default_scaling8[0],
          fallback_sps ? sps->scaling_matrix8[3] : default_scaling8[1]
      };
      int ret = 0;
      if (get_bits1(gb)) {
          ret |= decode_scaling_list(gb, scaling_matrix4[0], 16, default_scaling4[0], fallback[0]);        // Intra, Y
          ret |= decode_scaling_list(gb, scaling_matrix4[1], 16, default_scaling4[0], scaling_matrix4[0]); // Intra, Cr
          ret |= decode_scaling_list(gb, scaling_matrix4[2], 16, default_scaling4[0], scaling_matrix4[1]); // Intra, Cb
          ret |= decode_scaling_list(gb, scaling_matrix4[3], 16, default_scaling4[1], fallback[1]);        // Inter, Y
          ret |= decode_scaling_list(gb, scaling_matrix4[4], 16, default_scaling4[1], scaling_matrix4[3]); // Inter, Cr
          ret |= decode_scaling_list(gb, scaling_matrix4[5], 16, default_scaling4[1], scaling_matrix4[4]); // Inter, Cb
          if (is_sps || pps->transform_8x8_mode) {
              ret |= decode_scaling_list(gb, scaling_matrix8[0], 64, default_scaling8[0], fallback[2]); // Intra, Y
              ret |= decode_scaling_list(gb, scaling_matrix8[3], 64, default_scaling8[1], fallback[3]); // Inter, Y
              if (sps->chroma_format_idc == 3) {
                  ret |= decode_scaling_list(gb, scaling_matrix8[1], 64, default_scaling8[0], scaling_matrix8[0]); // Intra, Cr
                  ret |= decode_scaling_list(gb, scaling_matrix8[4], 64, default_scaling8[1], scaling_matrix8[3]); // Inter, Cr
                  ret |= decode_scaling_list(gb, scaling_matrix8[2], 64, default_scaling8[0], scaling_matrix8[1]); // Intra, Cb
                  ret |= decode_scaling_list(gb, scaling_matrix8[5], 64, default_scaling8[1], scaling_matrix8[4]); // Inter, Cb
              }
          }
          if (!ret)
              ret = is_sps;
      }
  
      return ret;
  }
  
  void ff_h264_ps_uninit(H264ParamSets *ps)
  {
      int i;
  
      for (i = 0; i < MAX_SPS_COUNT; i++)
          av_buffer_unref(&ps->sps_list[i]);
  
      for (i = 0; i < MAX_PPS_COUNT; i++)
          av_buffer_unref(&ps->pps_list[i]);
  
      av_buffer_unref(&ps->sps_ref);
      av_buffer_unref(&ps->pps_ref);
  
      ps->pps = NULL;
      ps->sps = NULL;
  }
  
  int ff_h264_decode_seq_parameter_set(GetBitContext *gb, AVCodecContext *avctx,
                                       H264ParamSets *ps, int ignore_truncation)
  {
      AVBufferRef *sps_buf;
      int profile_idc, level_idc, constraint_set_flags = 0;
      unsigned int sps_id;
      int i, log2_max_frame_num_minus4;
      SPS *sps;
      int ret;
  
      sps_buf = av_buffer_allocz(sizeof(*sps));
      if (!sps_buf)
          return AVERROR(ENOMEM);
      sps = (SPS*)sps_buf->data;
  
      sps->data_size = gb->buffer_end - gb->buffer;
      if (sps->data_size > sizeof(sps->data)) {
          av_log(avctx, AV_LOG_WARNING, "Truncating likely oversized SPS\n");
          sps->data_size = sizeof(sps->data);
      }
      memcpy(sps->data, gb->buffer, sps->data_size);
  
      profile_idc           = get_bits(gb, 8);
      constraint_set_flags |= get_bits1(gb) << 0;   // constraint_set0_flag
      constraint_set_flags |= get_bits1(gb) << 1;   // constraint_set1_flag
      constraint_set_flags |= get_bits1(gb) << 2;   // constraint_set2_flag
      constraint_set_flags |= get_bits1(gb) << 3;   // constraint_set3_flag
      constraint_set_flags |= get_bits1(gb) << 4;   // constraint_set4_flag
      constraint_set_flags |= get_bits1(gb) << 5;   // constraint_set5_flag
      skip_bits(gb, 2);                             // reserved_zero_2bits
      level_idc = get_bits(gb, 8);
      sps_id    = get_ue_golomb_31(gb);
  
      if (sps_id >= MAX_SPS_COUNT) {
          av_log(avctx, AV_LOG_ERROR, "sps_id %u out of range\n", sps_id);
          goto fail;
      }
  
      sps->sps_id               = sps_id;
      sps->time_offset_length   = 24;
      sps->profile_idc          = profile_idc;
      sps->constraint_set_flags = constraint_set_flags;
      sps->level_idc            = level_idc;
      sps->full_range           = -1;
  
      memset(sps->scaling_matrix4, 16, sizeof(sps->scaling_matrix4));
      memset(sps->scaling_matrix8, 16, sizeof(sps->scaling_matrix8));
      sps->scaling_matrix_present = 0;
      sps->colorspace = 2; //AVCOL_SPC_UNSPECIFIED
  
      if (sps->profile_idc == 100 ||  // High profile
          sps->profile_idc == 110 ||  // High10 profile
          sps->profile_idc == 122 ||  // High422 profile
          sps->profile_idc == 244 ||  // High444 Predictive profile
          sps->profile_idc ==  44 ||  // Cavlc444 profile
          sps->profile_idc ==  83 ||  // Scalable Constrained High profile (SVC)
          sps->profile_idc ==  86 ||  // Scalable High Intra profile (SVC)
          sps->profile_idc == 118 ||  // Stereo High profile (MVC)
          sps->profile_idc == 128 ||  // Multiview High profile (MVC)
          sps->profile_idc == 138 ||  // Multiview Depth High profile (MVCD)
          sps->profile_idc == 144) {  // old High444 profile
          sps->chroma_format_idc = get_ue_golomb_31(gb);
          if (sps->chroma_format_idc > 3U) {
              avpriv_request_sample(avctx, "chroma_format_idc %u",
                                    sps->chroma_format_idc);
              goto fail;
          } else if (sps->chroma_format_idc == 3) {
              sps->residual_color_transform_flag = get_bits1(gb);
              if (sps->residual_color_transform_flag) {
                  av_log(avctx, AV_LOG_ERROR, "separate color planes are not supported\n");
                  goto fail;
              }
          }
          sps->bit_depth_luma   = get_ue_golomb(gb) + 8;
          sps->bit_depth_chroma = get_ue_golomb(gb) + 8;
          if (sps->bit_depth_chroma != sps->bit_depth_luma) {
              avpriv_request_sample(avctx,
                                    "Different chroma and luma bit depth");
              goto fail;
          }
          if (sps->bit_depth_luma   < 8 || sps->bit_depth_luma   > 14 ||
              sps->bit_depth_chroma < 8 || sps->bit_depth_chroma > 14) {
              av_log(avctx, AV_LOG_ERROR, "illegal bit depth value (%d, %d)\n",
                     sps->bit_depth_luma, sps->bit_depth_chroma);
              goto fail;
          }
          sps->transform_bypass = get_bits1(gb);
          ret = decode_scaling_matrices(gb, sps, NULL, 1,
                                        sps->scaling_matrix4, sps->scaling_matrix8);
          if (ret < 0)
              goto fail;
          sps->scaling_matrix_present |= ret;
      } else {
          sps->chroma_format_idc = 1;
          sps->bit_depth_luma    = 8;
          sps->bit_depth_chroma  = 8;
      }
  
      log2_max_frame_num_minus4 = get_ue_golomb(gb);
      if (log2_max_frame_num_minus4 < MIN_LOG2_MAX_FRAME_NUM - 4 ||
          log2_max_frame_num_minus4 > MAX_LOG2_MAX_FRAME_NUM - 4) {
          av_log(avctx, AV_LOG_ERROR,
                 "log2_max_frame_num_minus4 out of range (0-12): %d\n",
                 log2_max_frame_num_minus4);
          goto fail;
      }
      sps->log2_max_frame_num = log2_max_frame_num_minus4 + 4;
  
      sps->poc_type = get_ue_golomb_31(gb);
  
      if (sps->poc_type == 0) { // FIXME #define
          unsigned t = get_ue_golomb(gb);
          if (t>12) {
              av_log(avctx, AV_LOG_ERROR, "log2_max_poc_lsb (%d) is out of range\n", t);
              goto fail;
          }
          sps->log2_max_poc_lsb = t + 4;
      } else if (sps->poc_type == 1) { // FIXME #define
          sps->delta_pic_order_always_zero_flag = get_bits1(gb);
          sps->offset_for_non_ref_pic           = get_se_golomb(gb);
          sps->offset_for_top_to_bottom_field   = get_se_golomb(gb);
          sps->poc_cycle_length                 = get_ue_golomb(gb);
  
          if ((unsigned)sps->poc_cycle_length >=
              FF_ARRAY_ELEMS(sps->offset_for_ref_frame)) {
              av_log(avctx, AV_LOG_ERROR,
                     "poc_cycle_length overflow %d\n", sps->poc_cycle_length);
              goto fail;
          }
  
          for (i = 0; i < sps->poc_cycle_length; i++)
              sps->offset_for_ref_frame[i] = get_se_golomb(gb);
      } else if (sps->poc_type != 2) {
          av_log(avctx, AV_LOG_ERROR, "illegal POC type %d\n", sps->poc_type);
          goto fail;
      }
  
      sps->ref_frame_count = get_ue_golomb_31(gb);
      if (avctx->codec_tag == MKTAG('S', 'M', 'V', '2'))
          sps->ref_frame_count = FFMAX(2, sps->ref_frame_count);
      if (sps->ref_frame_count > MAX_DELAYED_PIC_COUNT) {
          av_log(avctx, AV_LOG_ERROR,
                 "too many reference frames %d\n", sps->ref_frame_count);
          goto fail;
      }
      sps->gaps_in_frame_num_allowed_flag = get_bits1(gb);
      sps->mb_width                       = get_ue_golomb(gb) + 1;
      sps->mb_height                      = get_ue_golomb(gb) + 1;
  
      sps->frame_mbs_only_flag = get_bits1(gb);
  
      if (sps->mb_height >= INT_MAX / 2U) {
          av_log(avctx, AV_LOG_ERROR, "height overflow\n");
          goto fail;
      }
      sps->mb_height *= 2 - sps->frame_mbs_only_flag;
  
      if (!sps->frame_mbs_only_flag)
          sps->mb_aff = get_bits1(gb);
      else
          sps->mb_aff = 0;
  
      if ((unsigned)sps->mb_width  >= INT_MAX / 16 ||
          (unsigned)sps->mb_height >= INT_MAX / 16 ||
          av_image_check_size(16 * sps->mb_width,
                              16 * sps->mb_height, 0, avctx)) {
          av_log(avctx, AV_LOG_ERROR, "mb_width/height overflow\n");
          goto fail;
      }
  
      sps->direct_8x8_inference_flag = get_bits1(gb);
  
  #ifndef ALLOW_INTERLACE
      if (sps->mb_aff)
          av_log(avctx, AV_LOG_ERROR,
                 "MBAFF support not included; enable it at compile-time.\n");
  #endif
      sps->crop = get_bits1(gb);
      if (sps->crop) {
          unsigned int crop_left   = get_ue_golomb(gb);
          unsigned int crop_right  = get_ue_golomb(gb);
          unsigned int crop_top    = get_ue_golomb(gb);
          unsigned int crop_bottom = get_ue_golomb(gb);
          int width  = 16 * sps->mb_width;
          int height = 16 * sps->mb_height;
  
          if (avctx->flags2 & AV_CODEC_FLAG2_IGNORE_CROP) {
              av_log(avctx, AV_LOG_DEBUG, "discarding sps cropping, original "
                                             "values are l:%d r:%d t:%d b:%d\n",
                     crop_left, crop_right, crop_top, crop_bottom);
  
              sps->crop_left   =
              sps->crop_right  =
              sps->crop_top    =
              sps->crop_bottom = 0;
          } else {
              int vsub   = (sps->chroma_format_idc == 1) ? 1 : 0;
              int hsub   = (sps->chroma_format_idc == 1 ||
                            sps->chroma_format_idc == 2) ? 1 : 0;
              int step_x = 1 << hsub;
              int step_y = (2 - sps->frame_mbs_only_flag) << vsub;
  
              if (crop_left  > (unsigned)INT_MAX / 4 / step_x ||
                  crop_right > (unsigned)INT_MAX / 4 / step_x ||
                  crop_top   > (unsigned)INT_MAX / 4 / step_y ||
                  crop_bottom> (unsigned)INT_MAX / 4 / step_y ||
                  (crop_left + crop_right ) * step_x >= width ||
                  (crop_top  + crop_bottom) * step_y >= height
              ) {
                  av_log(avctx, AV_LOG_ERROR, "crop values invalid %d %d %d %d / %d %d\n", crop_left, crop_right, crop_top, crop_bottom, width, height);
                  goto fail;
              }
  
              sps->crop_left   = crop_left   * step_x;
              sps->crop_right  = crop_right  * step_x;
              sps->crop_top    = crop_top    * step_y;
              sps->crop_bottom = crop_bottom * step_y;
          }
      } else {
          sps->crop_left   =
          sps->crop_right  =
          sps->crop_top    =
          sps->crop_bottom =
          sps->crop        = 0;
      }
  
      sps->vui_parameters_present_flag = get_bits1(gb);
      if (sps->vui_parameters_present_flag) {
          int ret = decode_vui_parameters(gb, avctx, sps);
          if (ret < 0)
              goto fail;
      }
  
      if (get_bits_left(gb) < 0) {
          av_log(avctx, ignore_truncation ? AV_LOG_WARNING : AV_LOG_ERROR,
                 "Overread %s by %d bits\n", sps->vui_parameters_present_flag ? "VUI" : "SPS", -get_bits_left(gb));
          if (!ignore_truncation)
              goto fail;
      }
  
      /* if the maximum delay is not stored in the SPS, derive it based on the
       * level */
      if (!sps->bitstream_restriction_flag &&
          (sps->ref_frame_count || avctx->strict_std_compliance >= FF_COMPLIANCE_STRICT)) {
          sps->num_reorder_frames = MAX_DELAYED_PIC_COUNT - 1;
          for (i = 0; i < FF_ARRAY_ELEMS(level_max_dpb_mbs); i++) {
              if (level_max_dpb_mbs[i][0] == sps->level_idc) {
                  sps->num_reorder_frames = FFMIN(level_max_dpb_mbs[i][1] / (sps->mb_width * sps->mb_height),
                                                  sps->num_reorder_frames);
                  break;
              }
          }
      }
  
      if (!sps->sar.den)
          sps->sar.den = 1;
  
      if (avctx->debug & FF_DEBUG_PICT_INFO) {
          static const char csp[4][5] = { "Gray", "420", "422", "444" };
          av_log(avctx, AV_LOG_DEBUG,
                 "sps:%u profile:%d/%d poc:%d ref:%d %dx%d %s %s crop:%u/%u/%u/%u %s %s %"PRId32"/%"PRId32" b%d reo:%d\n",
                 sps_id, sps->profile_idc, sps->level_idc,
                 sps->poc_type,
                 sps->ref_frame_count,
                 sps->mb_width, sps->mb_height,
                 sps->frame_mbs_only_flag ? "FRM" : (sps->mb_aff ? "MB-AFF" : "PIC-AFF"),
                 sps->direct_8x8_inference_flag ? "8B8" : "",
                 sps->crop_left, sps->crop_right,
                 sps->crop_top, sps->crop_bottom,
                 sps->vui_parameters_present_flag ? "VUI" : "",
                 csp[sps->chroma_format_idc],
                 sps->timing_info_present_flag ? sps->num_units_in_tick : 0,
                 sps->timing_info_present_flag ? sps->time_scale : 0,
                 sps->bit_depth_luma,
                 sps->bitstream_restriction_flag ? sps->num_reorder_frames : -1
                 );
      }
  
      /* check if this is a repeat of an already parsed SPS, then keep the
       * original one.
       * otherwise drop all PPSes that depend on it */
      if (ps->sps_list[sps_id] &&
          !memcmp(ps->sps_list[sps_id]->data, sps_buf->data, sps_buf->size)) {
          av_buffer_unref(&sps_buf);
      } else {
          remove_sps(ps, sps_id);
          ps->sps_list[sps_id] = sps_buf;
      }
  
      return 0;
  
  fail:
      av_buffer_unref(&sps_buf);
      return AVERROR_INVALIDDATA;
  }
  
  static void init_dequant8_coeff_table(PPS *pps, const SPS *sps)
  {
      int i, j, q, x;
      const int max_qp = 51 + 6 * (sps->bit_depth_luma - 8);
  
      for (i = 0; i < 6; i++) {
          pps->dequant8_coeff[i] = pps->dequant8_buffer[i];
          for (j = 0; j < i; j++)
              if (!memcmp(pps->scaling_matrix8[j], pps->scaling_matrix8[i],
                          64 * sizeof(uint8_t))) {
                  pps->dequant8_coeff[i] = pps->dequant8_buffer[j];
                  break;
              }
          if (j < i)
              continue;
  
          for (q = 0; q < max_qp + 1; q++) {
              int shift = ff_h264_quant_div6[q];
              int idx   = ff_h264_quant_rem6[q];
              for (x = 0; x < 64; x++)
                  pps->dequant8_coeff[i][q][(x >> 3) | ((x & 7) << 3)] =
                      ((uint32_t)ff_h264_dequant8_coeff_init[idx][ff_h264_dequant8_coeff_init_scan[((x >> 1) & 12) | (x & 3)]] *
                       pps->scaling_matrix8[i][x]) << shift;
          }
      }
  }
  
  static void init_dequant4_coeff_table(PPS *pps, const SPS *sps)
  {
      int i, j, q, x;
      const int max_qp = 51 + 6 * (sps->bit_depth_luma - 8);
      for (i = 0; i < 6; i++) {
          pps->dequant4_coeff[i] = pps->dequant4_buffer[i];
          for (j = 0; j < i; j++)
              if (!memcmp(pps->scaling_matrix4[j], pps->scaling_matrix4[i],
                          16 * sizeof(uint8_t))) {
                  pps->dequant4_coeff[i] = pps->dequant4_buffer[j];
                  break;
              }
          if (j < i)
              continue;
  
          for (q = 0; q < max_qp + 1; q++) {
              int shift = ff_h264_quant_div6[q] + 2;
              int idx   = ff_h264_quant_rem6[q];
              for (x = 0; x < 16; x++)
                  pps->dequant4_coeff[i][q][(x >> 2) | ((x << 2) & 0xF)] =
                      ((uint32_t)ff_h264_dequant4_coeff_init[idx][(x & 1) + ((x >> 2) & 1)] *
                       pps->scaling_matrix4[i][x]) << shift;
          }
      }
  }
  
  static void init_dequant_tables(PPS *pps, const SPS *sps)
  {
      int i, x;
      init_dequant4_coeff_table(pps, sps);
      memset(pps->dequant8_coeff, 0, sizeof(pps->dequant8_coeff));
  
      if (pps->transform_8x8_mode)
          init_dequant8_coeff_table(pps, sps);
      if (sps->transform_bypass) {
          for (i = 0; i < 6; i++)
              for (x = 0; x < 16; x++)
                  pps->dequant4_coeff[i][0][x] = 1 << 6;
          if (pps->transform_8x8_mode)
              for (i = 0; i < 6; i++)
                  for (x = 0; x < 64; x++)
                      pps->dequant8_coeff[i][0][x] = 1 << 6;
      }
  }
  
  static void build_qp_table(PPS *pps, int t, int index, const int depth)
  {
      int i;
      const int max_qp = 51 + 6 * (depth - 8);
      for (i = 0; i < max_qp + 1; i++)
          pps->chroma_qp_table[t][i] =
              ff_h264_chroma_qp[depth - 8][av_clip(i + index, 0, max_qp)];
  }
  
  static int more_rbsp_data_in_pps(const SPS *sps, void *logctx)
  {
      int profile_idc = sps->profile_idc;
  
      if ((profile_idc == 66 || profile_idc == 77 ||
           profile_idc == 88) && (sps->constraint_set_flags & 7)) {
          av_log(logctx, AV_LOG_VERBOSE,
                 "Current profile doesn't provide more RBSP data in PPS, skipping\n");
          return 0;
      }
  
      return 1;
  }
  
  int ff_h264_decode_picture_parameter_set(GetBitContext *gb, AVCodecContext *avctx,
                                           H264ParamSets *ps, int bit_length)
  {
      AVBufferRef *pps_buf;
      const SPS *sps;
      unsigned int pps_id = get_ue_golomb(gb);
      PPS *pps;
      int qp_bd_offset;
      int bits_left;
      int ret;
  
      if (pps_id >= MAX_PPS_COUNT) {
          av_log(avctx, AV_LOG_ERROR, "pps_id %u out of range\n", pps_id);
          return AVERROR_INVALIDDATA;
      }
  
      pps_buf = av_buffer_allocz(sizeof(*pps));
      if (!pps_buf)
          return AVERROR(ENOMEM);
      pps = (PPS*)pps_buf->data;
  
      pps->data_size = gb->buffer_end - gb->buffer;
      if (pps->data_size > sizeof(pps->data)) {
          av_log(avctx, AV_LOG_WARNING, "Truncating likely oversized PPS "
                 "(%"SIZE_SPECIFIER" > %"SIZE_SPECIFIER")\n",
                 pps->data_size, sizeof(pps->data));
          pps->data_size = sizeof(pps->data);
      }
      memcpy(pps->data, gb->buffer, pps->data_size);
  
      pps->sps_id = get_ue_golomb_31(gb);
      if ((unsigned)pps->sps_id >= MAX_SPS_COUNT ||
          !ps->sps_list[pps->sps_id]) {
          av_log(avctx, AV_LOG_ERROR, "sps_id %u out of range\n", pps->sps_id);
          ret = AVERROR_INVALIDDATA;
          goto fail;
      }
      sps = (const SPS*)ps->sps_list[pps->sps_id]->data;
      if (sps->bit_depth_luma > 14) {
          av_log(avctx, AV_LOG_ERROR,
                 "Invalid luma bit depth=%d\n",
                 sps->bit_depth_luma);
          ret = AVERROR_INVALIDDATA;
          goto fail;
      } else if (sps->bit_depth_luma == 11 || sps->bit_depth_luma == 13) {
          avpriv_report_missing_feature(avctx,
                 "Unimplemented luma bit depth=%d",
                 sps->bit_depth_luma);
          ret = AVERROR_PATCHWELCOME;
          goto fail;
      }
  
      pps->cabac             = get_bits1(gb);
      pps->pic_order_present = get_bits1(gb);
      pps->slice_group_count = get_ue_golomb(gb) + 1;
      if (pps->slice_group_count > 1) {
          pps->mb_slice_group_map_type = get_ue_golomb(gb);
          av_log(avctx, AV_LOG_ERROR, "FMO not supported\n");
      }
      pps->ref_count[0] = get_ue_golomb(gb) + 1;
      pps->ref_count[1] = get_ue_golomb(gb) + 1;
      if (pps->ref_count[0] - 1 > 32 - 1 || pps->ref_count[1] - 1 > 32 - 1) {
          av_log(avctx, AV_LOG_ERROR, "reference overflow (pps)\n");
          ret = AVERROR_INVALIDDATA;
          goto fail;
      }
  
      qp_bd_offset = 6 * (sps->bit_depth_luma - 8);
  
      pps->weighted_pred                        = get_bits1(gb);
      pps->weighted_bipred_idc                  = get_bits(gb, 2);
      pps->init_qp                              = get_se_golomb(gb) + 26U + qp_bd_offset;
      pps->init_qs                              = get_se_golomb(gb) + 26U + qp_bd_offset;
      pps->chroma_qp_index_offset[0]            = get_se_golomb(gb);
      if (pps->chroma_qp_index_offset[0] < -12 || pps->chroma_qp_index_offset[0] > 12) {
          ret = AVERROR_INVALIDDATA;
          goto fail;
      }
  
      pps->deblocking_filter_parameters_present = get_bits1(gb);
      pps->constrained_intra_pred               = get_bits1(gb);
      pps->redundant_pic_cnt_present            = get_bits1(gb);
  
      pps->transform_8x8_mode = 0;
      memcpy(pps->scaling_matrix4, sps->scaling_matrix4,
             sizeof(pps->scaling_matrix4));
      memcpy(pps->scaling_matrix8, sps->scaling_matrix8,
             sizeof(pps->scaling_matrix8));
  
      bits_left = bit_length - get_bits_count(gb);
      if (bits_left > 0 && more_rbsp_data_in_pps(sps, avctx)) {
          pps->transform_8x8_mode = get_bits1(gb);
          ret = decode_scaling_matrices(gb, sps, pps, 0,
                                  pps->scaling_matrix4, pps->scaling_matrix8);
          if (ret < 0)
              goto fail;
          // second_chroma_qp_index_offset
          pps->chroma_qp_index_offset[1] = get_se_golomb(gb);
          if (pps->chroma_qp_index_offset[1] < -12 || pps->chroma_qp_index_offset[1] > 12) {
              ret = AVERROR_INVALIDDATA;
              goto fail;
          }
      } else {
          pps->chroma_qp_index_offset[1] = pps->chroma_qp_index_offset[0];
      }
  
      build_qp_table(pps, 0, pps->chroma_qp_index_offset[0],
                     sps->bit_depth_luma);
      build_qp_table(pps, 1, pps->chroma_qp_index_offset[1],
                     sps->bit_depth_luma);
  
      init_dequant_tables(pps, sps);
  
      if (pps->chroma_qp_index_offset[0] != pps->chroma_qp_index_offset[1])
          pps->chroma_qp_diff = 1;
  
      if (avctx->debug & FF_DEBUG_PICT_INFO) {
          av_log(avctx, AV_LOG_DEBUG,
                 "pps:%u sps:%u %s slice_groups:%d ref:%u/%u %s qp:%d/%d/%d/%d %s %s %s %s\n",
                 pps_id, pps->sps_id,
                 pps->cabac ? "CABAC" : "CAVLC",
                 pps->slice_group_count,
                 pps->ref_count[0], pps->ref_count[1],
                 pps->weighted_pred ? "weighted" : "",
                 pps->init_qp, pps->init_qs, pps->chroma_qp_index_offset[0], pps->chroma_qp_index_offset[1],
                 pps->deblocking_filter_parameters_present ? "LPAR" : "",
                 pps->constrained_intra_pred ? "CONSTR" : "",
                 pps->redundant_pic_cnt_present ? "REDU" : "",
                 pps->transform_8x8_mode ? "8x8DCT" : "");
      }
  
      remove_pps(ps, pps_id);
      ps->pps_list[pps_id] = pps_buf;
  
      return 0;
  
  fail:
      av_buffer_unref(&pps_buf);
      return ret;
  }
  