/*
  * Canopus common routines
  * Copyright (c) 2015 Vittorio Giovara <vittorio.giovara@gmail.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 <stdint.h>
 
 #include "libavutil/rational.h"
 
 #include "avcodec.h"
 #include "bytestream.h"
 #include "canopus.h"
 
 int ff_canopus_parse_info_tag(AVCodecContext *avctx,
                               const uint8_t *src, size_t size)
 {
     GetByteContext gbc;
     int par_x, par_y, field_order;
 
     bytestream2_init(&gbc, src, size);
 
     /* Parse aspect ratio. */
     bytestream2_skip(&gbc, 8); // unknown, 16 bits 1
     par_x = bytestream2_get_le32(&gbc);
     par_y = bytestream2_get_le32(&gbc);
     if (par_x && par_y)
         av_reduce(&avctx->sample_aspect_ratio.num,
                   &avctx->sample_aspect_ratio.den,
                   par_x, par_y, 255);
 
     /* Short INFO tag (used in CLLC) has only AR data. */
     if (size == 0x18)
         return 0;
 
     bytestream2_skip(&gbc, 16); // unknown RDRT tag
 
     /* Parse FIEL tag. */
     bytestream2_skip(&gbc, 8); // 'FIEL' and 4 bytes 0
     field_order = bytestream2_get_le32(&gbc);
     switch (field_order) {
     case 0: avctx->field_order = AV_FIELD_TT; break;
     case 1: avctx->field_order = AV_FIELD_BB; break;
     case 2: avctx->field_order = AV_FIELD_PROGRESSIVE; break;
     }
 
     return 0;
 }