Function EncodeChunk

third-party/tinyexr/tinyexr.h:7371–7600

}

static int EncodeChunk(const EXRImage* exr_image, const EXRHeader* exr_header,
                       const std::vector<ChannelInfo>& channels,
                       int num_blocks,
                       tinyexr_uint64 chunk_offset, // starting offset of current chunk
                       bool is_multipart,
                       OffsetData& offset_data, // output block offsets, must be initialized
                       std::vector<std::vector<unsigned char> >& data_list, // output
                       tinyexr_uint64& total_size, // output: ending offset of current chunk
                       std::string* err) {
  int num_scanlines = NumScanlines(exr_header->compression_type);

  data_list.resize(num_blocks);

  std::vector<size_t> channel_offset_list(
    static_cast<size_t>(exr_header->num_channels));

  int pixel_data_size = 0;
  {
    size_t channel_offset = 0;
    for (size_t c = 0; c < static_cast<size_t>(exr_header->num_channels); c++) {
      channel_offset_list[c] = channel_offset;
      if (channels[c].requested_pixel_type == TINYEXR_PIXELTYPE_HALF) {
        pixel_data_size += sizeof(unsigned short);
        channel_offset += sizeof(unsigned short);
      } else if (channels[c].requested_pixel_type ==
                 TINYEXR_PIXELTYPE_FLOAT) {
        pixel_data_size += sizeof(float);
        channel_offset += sizeof(float);
      } else if (channels[c].requested_pixel_type == TINYEXR_PIXELTYPE_UINT) {
        pixel_data_size += sizeof(unsigned int);
        channel_offset += sizeof(unsigned int);
      } else {
        if (err) {
          (*err) += "Invalid requested_pixel_type.\n";
        }
        return TINYEXR_ERROR_INVALID_DATA;
      }
    }
  }

  const void* compression_param = 0;
#if TINYEXR_USE_ZFP
  tinyexr::ZFPCompressionParam zfp_compression_param;

  // Use ZFP compression parameter from custom attributes(if such a parameter
  // exists)
  {
    std::string e;
    bool ret = tinyexr::FindZFPCompressionParam(
      &zfp_compression_param, exr_header->custom_attributes,
      exr_header->num_custom_attributes, &e);

    if (!ret) {
      // Use predefined compression parameter.
      zfp_compression_param.type = 0;
      zfp_compression_param.rate = 2;
    }
    compression_param = &zfp_compression_param;