text: /*
   * Copyright (c) 2016 Google Inc.
   * Copyright (c) 2016 KongQun Yang (kqyang@google.com)
   *
   * 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
   */
  
  #include "libavutil/pixdesc.h"
  #include "libavutil/pixfmt.h"
  #include "vpcc.h"
  
  enum VPX_CHROMA_SUBSAMPLING
  {
      VPX_SUBSAMPLING_420_VERTICAL = 0,
      VPX_SUBSAMPLING_420_COLLOCATED_WITH_LUMA = 1,
      VPX_SUBSAMPLING_422 = 2,
      VPX_SUBSAMPLING_444 = 3,
  };
  
  static int get_vpx_chroma_subsampling(AVFormatContext *s,
                                        enum AVPixelFormat pixel_format,
                                        enum AVChromaLocation chroma_location)
  {
      int chroma_w, chroma_h;
      if (av_pix_fmt_get_chroma_sub_sample(pixel_format, &chroma_w, &chroma_h) == 0) {
          if (chroma_w == 1 && chroma_h == 1) {
              return (chroma_location == AVCHROMA_LOC_LEFT)
                         ? VPX_SUBSAMPLING_420_VERTICAL
                         : VPX_SUBSAMPLING_420_COLLOCATED_WITH_LUMA;
          } else if (chroma_w == 1 && chroma_h == 0) {
              return VPX_SUBSAMPLING_422;
          } else if (chroma_w == 0 && chroma_h == 0) {
              return VPX_SUBSAMPLING_444;
          }
      }
      av_log(s, AV_LOG_ERROR, "Unsupported pixel format (%d)\n", pixel_format);
      return -1;
  }
  
  static int get_bit_depth(AVFormatContext *s, enum AVPixelFormat pixel_format)
  {
      const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pixel_format);
      if (desc == NULL) {
          av_log(s, AV_LOG_ERROR, "Unsupported pixel format (%d)\n",
                 pixel_format);
          return -1;
      }
      return desc->comp[0].depth;
  }
  
  static int get_vpx_video_full_range_flag(enum AVColorRange color_range)
  {
      return color_range == AVCOL_RANGE_JPEG;
  }
  
  int ff_isom_get_vpcc_features(AVFormatContext *s, AVCodecParameters *par,
                                VPCC *vpcc)
  {
      int profile = par->profile;
      int level = par->level == FF_LEVEL_UNKNOWN ? 0 : par->level;
      int bit_depth = get_bit_depth(s, par->format);
      int vpx_chroma_subsampling =
          get_vpx_chroma_subsampling(s, par->format, par->chroma_location);
      int vpx_video_full_range_flag =
          get_vpx_video_full_range_flag(par->color_range);
  
      if (bit_depth < 0 || vpx_chroma_subsampling < 0)
          return AVERROR_INVALIDDATA;
  
      if (profile == FF_PROFILE_UNKNOWN) {
          if (vpx_chroma_subsampling == VPX_SUBSAMPLING_420_VERTICAL ||
              vpx_chroma_subsampling == VPX_SUBSAMPLING_420_COLLOCATED_WITH_LUMA) {
              profile = (bit_depth == 8) ? FF_PROFILE_VP9_0 : FF_PROFILE_VP9_2;
          } else {
              profile = (bit_depth == 8) ? FF_PROFILE_VP9_1 : FF_PROFILE_VP9_3;
          }
      }
  
      vpcc->profile            = profile;
      vpcc->level              = level;
      vpcc->bitdepth           = bit_depth;
      vpcc->chroma_subsampling = vpx_chroma_subsampling;
      vpcc->full_range_flag    = vpx_video_full_range_flag;
  
      return 0;
  }
  
  int ff_isom_write_vpcc(AVFormatContext *s, AVIOContext *pb,
                         AVCodecParameters *par)
  {
      VPCC vpcc;
      int ret;
  
      ret = ff_isom_get_vpcc_features(s, par, &vpcc);
      if (ret < 0)
          return ret;
  
      avio_w8(pb, vpcc.profile);
      avio_w8(pb, vpcc.level);
      avio_w8(pb, (vpcc.bitdepth << 4) | (vpcc.chroma_subsampling << 1) | vpcc.full_range_flag);
      avio_w8(pb, par->color_primaries);
      avio_w8(pb, par->color_trc);
      avio_w8(pb, par->color_space);
  
      // vp9 does not have codec initialization data.
      avio_wb16(pb, 0);
      return 0;
  }
  