yading@11: /*
yading@11:  * raw ADTS AAC demuxer
yading@11:  * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
yading@11:  * Copyright (c) 2009 Robert Swain ( rob opendot cl )
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "rawdec.h"
yading@11: #include "id3v1.h"
yading@11: 
yading@11: 
yading@11: static int adts_aac_probe(AVProbeData *p)
yading@11: {
yading@11:     int max_frames = 0, first_frames = 0;
yading@11:     int fsize, frames;
yading@11:     const uint8_t *buf0 = p->buf;
yading@11:     const uint8_t *buf2;
yading@11:     const uint8_t *buf;
yading@11:     const uint8_t *end = buf0 + p->buf_size - 7;
yading@11: 
yading@11:     buf = buf0;
yading@11: 
yading@11:     for(; buf < end; buf= buf2+1) {
yading@11:         buf2 = buf;
yading@11: 
yading@11:         for(frames = 0; buf2 < end; frames++) {
yading@11:             uint32_t header = AV_RB16(buf2);
yading@11:             if((header&0xFFF6) != 0xFFF0)
yading@11:                 break;
yading@11:             fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
yading@11:             if(fsize < 7)
yading@11:                 break;
yading@11:             fsize = FFMIN(fsize, end - buf2);
yading@11:             buf2 += fsize;
yading@11:         }
yading@11:         max_frames = FFMAX(max_frames, frames);
yading@11:         if(buf == buf0)
yading@11:             first_frames= frames;
yading@11:     }
yading@11:     if   (first_frames>=3) return AVPROBE_SCORE_MAX/2+1;
yading@11:     else if(max_frames>500)return AVPROBE_SCORE_MAX/2;
yading@11:     else if(max_frames>=3) return AVPROBE_SCORE_MAX/4;
yading@11:     else if(max_frames>=1) return 1;
yading@11:     else                   return 0;
yading@11: }
yading@11: 
yading@11: static int adts_aac_read_header(AVFormatContext *s)
yading@11: {
yading@11:     AVStream *st;
yading@11: 
yading@11:     st = avformat_new_stream(s, NULL);
yading@11:     if (!st)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id = s->iformat->raw_codec_id;
yading@11:     st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
yading@11: 
yading@11:     ff_id3v1_read(s);
yading@11: 
yading@11:     //LCM of all possible ADTS sample rates
yading@11:     avpriv_set_pts_info(st, 64, 1, 28224000);
yading@11: 
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_aac_demuxer = {
yading@11:     .name           = "aac",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
yading@11:     .read_probe     = adts_aac_probe,
yading@11:     .read_header    = adts_aac_read_header,
yading@11:     .read_packet    = ff_raw_read_partial_packet,
yading@11:     .flags          = AVFMT_GENERIC_INDEX,
yading@11:     .extensions     = "aac",
yading@11:     .raw_codec_id   = AV_CODEC_ID_AAC,
yading@11: };