Parser::parse_iref( int $num_remaining_bytes ): Avifinfo\Status

598  private function parse_iref( $num_remaining_bytes ) {599    do {600      $box    = new Box();601      $status = $box->parse( $this->handle, $this->num_parsed_boxes, $num_remaining_bytes );602      if ( $status != FOUND ) {603        return $status;604      }605 606      if ( $box->type == 'dimg' ) {607        // See ISO/IEC 14496-12:2015(E) 8.11.12.2608        $num_bytes_per_id = ( $box->version == 0 ) ? 2 : 4;609        $num_read_bytes   = $num_bytes_per_id + 2;610        if ( $box->content_size < $num_read_bytes ) {611          return INVALID;612        }613        if ( !( $data = read( $this->handle, $num_read_bytes ) ) ) {614          return TRUNCATED;615        }616        $from_item_id    = read_big_endian( $data, $num_bytes_per_id );617        $reference_count = read_big_endian( substr( $data, $num_bytes_per_id, 2 ), 2 );618 619        for ( $i = 0; $i < $reference_count; ++$i ) {620          if ( $i >= MAX_TILES ) {621            $this->data_was_skipped = true;622            break;623          }624          $num_read_bytes += $num_bytes_per_id;625          if ( $box->content_size < $num_read_bytes ) {626            return INVALID;627          }628          if ( !( $data = read( $this->handle, $num_bytes_per_id ) ) ) {629            return TRUNCATED;630          }631          $to_item_id = read_big_endian( $data, $num_bytes_per_id );632          $tile_count = count( $this->features->tiles );633          if ( $from_item_id <= MAX_VALUE && $to_item_id <= MAX_VALUE &&634               $tile_count < MAX_TILES ) {635            $this->features->tiles[$tile_count]                 = new Tile();636            $this->features->tiles[$tile_count]->tile_item_id   = $to_item_id;637            $this->features->tiles[$tile_count]->parent_item_id = $from_item_id;638          } else {639            $this->data_was_skipped = true;640          }641        }642 643        // If all features are available now, do not look further.644        $status = $this->features->get_primary_item_features();645        if ( $status != NOT_FOUND ) {646          return $status;647        }648 649        // Mostly if 'data_was_skipped'.650        if ( !skip( $this->handle, $box->content_size - $num_read_bytes ) ) {651          return TRUNCATED;652        }653      } else {654        if ( !skip( $this->handle, $box->content_size ) ) {655          return TRUNCATED;656        }657      }658      $num_remaining_bytes -= $box->size;659    } while ( $num_remaining_bytes > 0 );660    return NOT_FOUND;661  }