| /* |
| * 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 "internal.h" |
| #include "rawdec.h" |
| |
| #define LOAS_SYNC_WORD 0x2b7 |
| |
| static int loas_probe(const AVProbeData *p) |
| { |
| int max_frames = 0, first_frames = 0; |
| int fsize, frames; |
| const uint8_t *buf0 = p->buf; |
| const uint8_t *buf2; |
| const uint8_t *buf; |
| const 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) != LOAS_SYNC_WORD) |
| 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_EXTENSION + 1; |
| else if (max_frames > 100) |
| return AVPROBE_SCORE_EXTENSION; |
| else if (max_frames >= 3) |
| return AVPROBE_SCORE_EXTENSION / 2; |
| else |
| return 0; |
| } |
| |
| static int loas_read_header(AVFormatContext *s) |
| { |
| AVStream *st; |
| |
| st = avformat_new_stream(s, NULL); |
| if (!st) |
| return AVERROR(ENOMEM); |
| |
| st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
| st->codecpar->codec_id = s->iformat->raw_codec_id; |
| st->need_parsing = AVSTREAM_PARSE_FULL_RAW; |
| |
| //LCM of all possible AAC sample rates |
| avpriv_set_pts_info(st, 64, 1, 28224000); |
| |
| return 0; |
| } |
| |
| FF_RAW_DEMUXER_CLASS(loas) |
| 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, |
| .raw_codec_id = AV_CODEC_ID_AAC_LATM, |
| .priv_data_size = sizeof(FFRawDemuxerContext), |
| .priv_class = &loas_demuxer_class, |
| }; |