3 * Copyright (c) 2003 Fabrice Bellard
4 * Copyright (c) 2003 Michael Niedermayer
6 * This file is part of FFmpeg.
8 * FFmpeg 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.
13 * FFmpeg 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.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "mpegaudiodecheader.h"
25 #include "libavutil/common.h"
26 #include "libavformat/id3v1.h" // for ID3v1_TAG_SIZE
28 typedef struct MpegAudioParseContext {
34 } MpegAudioParseContext;
36 #define MPA_HEADER_SIZE 4
38 /* header + layer + bitrate + freq + lsf/mpeg25 */
39 #define SAME_HEADER_MASK \
40 (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
42 static int mpegaudio_parse(AVCodecParserContext *s1,
43 AVCodecContext *avctx,
44 const uint8_t **poutbuf, int *poutbuf_size,
45 const uint8_t *buf, int buf_size)
47 MpegAudioParseContext *s = s1->priv_data;
48 ParseContext *pc = &s->pc;
49 uint32_t state= pc->state;
51 int next= END_NOT_FOUND;
52 int flush = !buf_size;
54 for(i=0; i<buf_size; ){
56 int inc= FFMIN(buf_size - i, s->frame_size);
67 int ret, sr, channels, bit_rate, frame_size;
68 enum AVCodecID codec_id = avctx->codec_id;
70 state= (state<<8) + buf[i++];
72 ret = avpriv_mpa_decode_header2(state, &sr, &channels, &frame_size, &bit_rate, &codec_id);
77 int header_threshold = avctx->codec_id != AV_CODEC_ID_NONE && avctx->codec_id != codec_id;
78 if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
82 s->frame_size = ret-4;
84 if (s->header_count > header_threshold) {
85 avctx->sample_rate= sr;
86 avctx->channels = channels;
87 s1->duration = frame_size;
88 avctx->codec_id = codec_id;
89 if (s->no_bitrate || !avctx->bit_rate) {
91 avctx->bit_rate += (bit_rate - avctx->bit_rate) / (s->header_count - header_threshold);
95 if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
98 } else if (codec_id == AV_CODEC_ID_MP3ADU) {
99 avpriv_report_missing_feature(avctx,
100 "MP3ADU full parser");
101 return AVERROR_PATCHWELCOME;
111 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
117 if (flush && buf_size >= ID3v1_TAG_SIZE && memcmp(buf, "TAG", 3) == 0) {
124 *poutbuf_size = buf_size;
129 AVCodecParser ff_mpegaudio_parser = {
130 .codec_ids = { AV_CODEC_ID_MP1, AV_CODEC_ID_MP2, AV_CODEC_ID_MP3, AV_CODEC_ID_MP3ADU },
131 .priv_data_size = sizeof(MpegAudioParseContext),
132 .parser_parse = mpegaudio_parse,
133 .parser_close = ff_parse_close,