1/* 2 * raw ADTS AAC demuxer 3 * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> 4 * Copyright (c) 2009 Robert Swain ( rob opendot cl ) 5 * 6 * This file is part of Libav. 7 * 8 * Libav is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * Libav is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with Libav; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23#include "libavutil/intreadwrite.h" 24#include "avformat.h" 25#include "internal.h" 26#include "rawdec.h" 27#include "id3v1.h" 28 29 30static int adts_aac_probe(AVProbeData *p) 31{ 32 int max_frames = 0, first_frames = 0; 33 int fsize, frames; 34 uint8_t *buf0 = p->buf; 35 uint8_t *buf2; 36 uint8_t *buf; 37 uint8_t *end = buf0 + p->buf_size - 7; 38 39 buf = buf0; 40 41 for(; buf < end; buf= buf2+1) { 42 buf2 = buf; 43 44 for(frames = 0; buf2 < end; frames++) { 45 uint32_t header = AV_RB16(buf2); 46 if((header&0xFFF6) != 0xFFF0) 47 break; 48 fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF; 49 if(fsize < 7) 50 break; 51 buf2 += fsize; 52 } 53 max_frames = FFMAX(max_frames, frames); 54 if(buf == buf0) 55 first_frames= frames; 56 } 57 if (first_frames>=3) return AVPROBE_SCORE_MAX/2+1; 58 else if(max_frames>500)return AVPROBE_SCORE_MAX/2; 59 else if(max_frames>=3) return AVPROBE_SCORE_MAX/4; 60 else if(max_frames>=1) return 1; 61 else return 0; 62} 63 64static int adts_aac_read_header(AVFormatContext *s, 65 AVFormatParameters *ap) 66{ 67 AVStream *st; 68 69 st = avformat_new_stream(s, NULL); 70 if (!st) 71 return AVERROR(ENOMEM); 72 73 st->codec->codec_type = AVMEDIA_TYPE_AUDIO; 74 st->codec->codec_id = s->iformat->value; 75 st->need_parsing = AVSTREAM_PARSE_FULL; 76 77 ff_id3v1_read(s); 78 79 //LCM of all possible ADTS sample rates 80 avpriv_set_pts_info(st, 64, 1, 28224000); 81 82 return 0; 83} 84 85AVInputFormat ff_aac_demuxer = { 86 .name = "aac", 87 .long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC"), 88 .read_probe = adts_aac_probe, 89 .read_header = adts_aac_read_header, 90 .read_packet = ff_raw_read_partial_packet, 91 .flags= AVFMT_GENERIC_INDEX, 92 .extensions = "aac", 93 .value = CODEC_ID_AAC, 94}; 95