/*
  * 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;
 }
 
 AVCodecParser ff_dpx_parser = {
     .codec_ids      = { AV_CODEC_ID_DPX },
     .priv_data_size = sizeof(DPXParseContext),
     .parser_parse   = dpx_parse,
     .parser_close   = ff_parse_close,
 };