/* * LOAS AudioSyncStream demuxer * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at> * * 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 "libavutil/intreadwrite.h" #include "libavutil/internal.h" #include "avformat.h" #include "rawdec.h" static int loas_probe(AVProbeData *p) { int max_frames = 0, first_frames = 0; int fsize, frames; uint8_t *buf0 = p->buf; uint8_t *buf2; uint8_t *buf; uint8_t *end = buf0 + p->buf_size - 3; buf = buf0; for(; buf < end; buf= buf2+1) { buf2 = buf; for(frames = 0; buf2 < end; frames++) { uint32_t header = AV_RB24(buf2); if((header >> 13) != 0x2B7) break; fsize = (header & 0x1FFF) + 3; if(fsize < 7) break; fsize = FFMIN(fsize, end - buf2); buf2 += fsize; } max_frames = FFMAX(max_frames, frames); if(buf == buf0) first_frames= frames; } if (first_frames>=3) return AVPROBE_SCORE_MAX/2+1; else if(max_frames>100)return AVPROBE_SCORE_MAX/2; else if(max_frames>=3) return AVPROBE_SCORE_MAX/4; else if(max_frames>=1) return 1; else return 0; } static int loas_read_header(AVFormatContext *s, AVFormatParameters *ap) { AVStream *st; st = av_new_stream(s, 0); if (!st) return AVERROR(ENOMEM); st->codec->codec_type = AVMEDIA_TYPE_AUDIO; st->codec->codec_id = s->iformat->value; st->need_parsing = AVSTREAM_PARSE_FULL; //LCM of all possible AAC sample rates av_set_pts_info(st, 64, 1, 28224000); return 0; } AVInputFormat ff_loas_demuxer = { .name = "loas", .long_name = NULL_IF_CONFIG_SMALL("LOAS AudioSyncStream"), .read_probe = loas_probe, .read_header = loas_read_header, .read_packet = ff_raw_read_partial_packet, .flags= AVFMT_GENERIC_INDEX, .value = CODEC_ID_AAC_LATM, };