diff options
Diffstat (limited to 'libavformat/loasdec.c')
| -rw-r--r-- | libavformat/loasdec.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/libavformat/loasdec.c b/libavformat/loasdec.c new file mode 100644 index 0000000000..c41809be00 --- /dev/null +++ b/libavformat/loasdec.c @@ -0,0 +1,94 @@ +/* + * 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(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->codec->codec_type = AVMEDIA_TYPE_AUDIO; + st->codec->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; +} + +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, +}; |