/*
  * MJPEG parser

  * Copyright (c) 2000, 2001 Fabrice Bellard

  * Copyright (c) 2003 Alex Beregszaszi
  * Copyright (c) 2003-2004 Michael Niedermayer
  *
  * 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

  * MJPEG parser.
  */
 
 #include "parser.h"
 
 
 /**
  * finds the end of the current frame in the bitstream.
  * @return the position of the first byte of the next frame, or -1
  */
 static int find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size){
     int vop_found, i;
     uint16_t state;
 
     vop_found= pc->frame_start_found;
     state= pc->state;
 
     i=0;
     if(!vop_found){
         for(i=0; i<buf_size; i++){
             state= (state<<8) | buf[i];
             if(state == 0xFFD8){
                 i++;
                 vop_found=1;
                 break;
             }
         }
     }
 
     if(vop_found){
         /* EOF considered as end of frame */
         if (buf_size == 0)
             return 0;
         for(; i<buf_size; i++){
             state= (state<<8) | buf[i];
             if(state == 0xFFD8){
                 pc->frame_start_found=0;
                 pc->state=0;
                 return i-1;
             }
         }
     }
     pc->frame_start_found= vop_found;
     pc->state= state;
     return END_NOT_FOUND;
 }
 
 static int jpeg_parse(AVCodecParserContext *s,

                       AVCodecContext *avctx,
                       const uint8_t **poutbuf, int *poutbuf_size,
                       const uint8_t *buf, int buf_size)

 {
     ParseContext *pc = s->priv_data;
     int next;
 

     if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
         next= buf_size;
     }else{

         next= find_frame_end(pc, buf, buf_size);

         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
             *poutbuf = NULL;
             *poutbuf_size = 0;
             return buf_size;
         }

     }

 
     *poutbuf = buf;
     *poutbuf_size = buf_size;
     return next;
 }
 
 

 AVCodecParser ff_mjpeg_parser = {

     { CODEC_ID_MJPEG },
     sizeof(ParseContext),
     NULL,
     jpeg_parse,
     ff_parse_close,
 };