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/apetag.h" // for APE tag.
27 #include "libavformat/id3v1.h" // for ID3v1_TAG_SIZE
29 typedef struct MpegAudioParseContext {
35 } MpegAudioParseContext;
37 #define MPA_HEADER_SIZE 4
39 /* header + layer + freq + lsf/mpeg25 */
40 #define SAME_HEADER_MASK \
41 (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
43 static int mpegaudio_parse(AVCodecParserContext *s1,
44 AVCodecContext *avctx,
45 const uint8_t **poutbuf, int *poutbuf_size,
46 const uint8_t *buf, int buf_size)
48 MpegAudioParseContext *s = s1->priv_data;
49 ParseContext *pc = &s->pc;
50 uint32_t state= pc->state;
52 int next= END_NOT_FOUND;
53 int flush = !buf_size;
55 for(i=0; i<buf_size; ){
57 int inc= FFMIN(buf_size - i, s->frame_size);
68 int ret, sr, channels, bit_rate, frame_size;
69 enum AVCodecID codec_id = avctx->codec_id;
71 state= (state<<8) + buf[i++];
73 ret = ff_mpa_decode_header(state, &sr, &channels, &frame_size, &bit_rate, &codec_id);
78 int header_threshold = avctx->codec_id != AV_CODEC_ID_NONE && avctx->codec_id != codec_id;
79 if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
83 s->frame_size = ret-4;
85 if (s->header_count > header_threshold) {
86 avctx->sample_rate= sr;
87 avctx->channels = channels;
88 s1->duration = frame_size;
89 avctx->codec_id = codec_id;
90 if (s->no_bitrate || !avctx->bit_rate) {
92 avctx->bit_rate += (bit_rate - avctx->bit_rate) / (s->header_count - header_threshold);
96 if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
99 } else if (codec_id == AV_CODEC_ID_MP3ADU) {
100 avpriv_report_missing_feature(avctx,
101 "MP3ADU full parser");
102 return 0; /* parsers must not return error codes */
112 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
118 if (flush && buf_size >= ID3v1_TAG_SIZE && memcmp(buf, "TAG", 3) == 0) {
124 if (flush && buf_size >= APE_TAG_FOOTER_BYTES && memcmp(buf, APE_TAG_PREAMBLE, 8) == 0) {
131 *poutbuf_size = buf_size;
136 AVCodecParser ff_mpegaudio_parser = {
137 .codec_ids = { AV_CODEC_ID_MP1, AV_CODEC_ID_MP2, AV_CODEC_ID_MP3, AV_CODEC_ID_MP3ADU },
138 .priv_data_size = sizeof(MpegAudioParseContext),
139 .parser_parse = mpegaudio_parse,
140 .parser_close = ff_parse_close,