text: /*
   * DPX parser
   * Copyright (c) 2013 Paul B Mahol
   *
   * 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
   * DPX parser
   */
  
  #include "libavutil/bswap.h"
  #include "libavutil/common.h"
  
  #include "parser.h"
  
  typedef struct DPXParseContext {
      ParseContext pc;
      uint32_t index;
      uint32_t fsize;
      uint32_t remaining_size;
      int is_be;
  } DPXParseContext;
  
  static int dpx_parse(AVCodecParserContext *s, AVCodecContext *avctx,
                       const uint8_t **poutbuf, int *poutbuf_size,
                       const uint8_t *buf, int buf_size)
  {
      DPXParseContext *d = s->priv_data;
      uint32_t state = d->pc.state;
      int next = END_NOT_FOUND;
      int i = 0;
  
      s->pict_type = AV_PICTURE_TYPE_I;
  
      *poutbuf_size = 0;
      if (buf_size == 0)
          next = 0;
  
      if (!d->pc.frame_start_found) {
          for (; i < buf_size; i++) {
              state = (state << 8) | buf[i];
              if (state == MKBETAG('S','D','P','X') ||
                  state == MKTAG('S','D','P','X')) {
                  d->pc.frame_start_found = 1;
                  d->is_be = state == MKBETAG('S','D','P','X');
                  d->index = 0;
                  break;
              }
          }
          d->pc.state = state;
      } else {
          if (d->remaining_size) {
              i = FFMIN(d->remaining_size, buf_size);
              d->remaining_size -= i;
              if (d->remaining_size)
                  goto flush;
          }
      }
  
      for (; d->pc.frame_start_found && i < buf_size; i++) {
          d->pc.state = (d->pc.state << 8) | buf[i];
          d->index++;
          if (d->index == 17) {
              d->fsize = d->is_be ? d->pc.state : av_bswap32(d->pc.state);
              if (d->fsize <= 1664) {
                  d->pc.frame_start_found = 0;
                  goto flush;
              }
              if (d->fsize > buf_size - i + 19)
                  d->remaining_size = d->fsize - buf_size + i - 19;
              else
                  i += d->fsize - 19;
  
              break;
          } else if (d->index > 17) {
              if (d->pc.state == MKBETAG('S','D','P','X') ||
                  d->pc.state == MKTAG('S','D','P','X')) {
                  next = i - 3;
                  break;
              }
          }
      }
  
  flush:
      if (ff_combine_frame(&d->pc, next, &buf, &buf_size) < 0)
          return buf_size;
  
      d->pc.frame_start_found = 0;
  
      *poutbuf      = buf;
      *poutbuf_size = buf_size;
      return next;
  }
  
  const AVCodecParser ff_dpx_parser = {
      .codec_ids      = { AV_CODEC_ID_DPX },
      .priv_data_size = sizeof(DPXParseContext),
      .parser_parse   = dpx_parse,
      .parser_close   = ff_parse_close,
  };
  