/*

  * Common AAC and AC-3 parser

  * Copyright (c) 2003 Fabrice Bellard
  * Copyright (c) 2003 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
  */
 
 #include "parser.h"
 #include "aac_ac3_parser.h"
 

 int ff_aac_ac3_parse(AVCodecParserContext *s1,

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

     AACAC3ParseContext *s = s1->priv_data;

     ParseContext *pc = &s->pc;
     int len, i;

     int new_frame_start;

 get_next:

     i=END_NOT_FOUND;
     if(s->remaining_size <= buf_size){

         if(s->remaining_size && !s->need_next_header){

             i= s->remaining_size;
             s->remaining_size = 0;
         }else{ //we need a header first
             len=0;
             for(i=s->remaining_size; i<buf_size; i++){
                 s->state = (s->state<<8) + buf[i];

                 if((len=s->sync(s->state, s, &s->need_next_header, &new_frame_start)))

                     break;
             }
             if(len<=0){
                 i=END_NOT_FOUND;
             }else{

                 s->state=0;

                 i-= s->header_size -1;

                 s->remaining_size = len;

                 if(!new_frame_start || pc->index+i<=0){

                     s->remaining_size += i;

                     goto get_next;

                 }

             }
         }
     }

     if(ff_combine_frame(pc, i, &buf, &buf_size)<0){
         s->remaining_size -= FFMIN(s->remaining_size, buf_size);
         *poutbuf = NULL;
         *poutbuf_size = 0;
         return buf_size;
     }

     *poutbuf = buf;
     *poutbuf_size = buf_size;

     /* update codec info */
     avctx->sample_rate = s->sample_rate;

     if(s->codec_id)
         avctx->codec_id = s->codec_id;
 

     /* allow downmixing to stereo (or mono for AC-3) */

     if(avctx->request_channels > 0 &&
             avctx->request_channels < s->channels &&
             (avctx->request_channels <= 2 ||
             (avctx->request_channels == 1 &&

             (avctx->codec_id == CODEC_ID_AC3 ||
              avctx->codec_id == CODEC_ID_EAC3)))) {

         avctx->channels = avctx->request_channels;
     } else {
         avctx->channels = s->channels;
     }
     avctx->bit_rate = s->bit_rate;
     avctx->frame_size = s->samples;

 
     return i;

 }