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https://github.com/FFmpeg/FFmpeg.git
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eae0879d96
When parsing the Xing/Info tag, don't set the bit rate if it's an Info tag. When parsing the stream, don't override the bit rate if it's already set, otherwise calculate the mean bit rate from parsed frames. This way, the bit rate will be set correctly both for CBR and VBR streams. CC:libav-stable@libav.org Signed-off-by: Anton Khirnov <anton@khirnov.net>
114 lines
3.5 KiB
C
114 lines
3.5 KiB
C
/*
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* MPEG Audio parser
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* Copyright (c) 2003 Fabrice Bellard
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* Copyright (c) 2003 Michael Niedermayer
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "parser.h"
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#include "mpegaudiodecheader.h"
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#include "libavutil/common.h"
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typedef struct MpegAudioParseContext {
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ParseContext pc;
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int frame_size;
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uint32_t header;
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int header_count;
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int no_bitrate;
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} MpegAudioParseContext;
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#define MPA_HEADER_SIZE 4
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/* header + layer + bitrate + freq + lsf/mpeg25 */
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#define SAME_HEADER_MASK \
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(0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
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static int mpegaudio_parse(AVCodecParserContext *s1,
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AVCodecContext *avctx,
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const uint8_t **poutbuf, int *poutbuf_size,
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const uint8_t *buf, int buf_size)
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{
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MpegAudioParseContext *s = s1->priv_data;
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ParseContext *pc = &s->pc;
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uint32_t state= pc->state;
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int i;
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int next= END_NOT_FOUND;
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for(i=0; i<buf_size; ){
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if(s->frame_size){
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int inc= FFMIN(buf_size - i, s->frame_size);
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i += inc;
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s->frame_size -= inc;
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if(!s->frame_size){
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next= i;
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break;
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}
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}else{
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while(i<buf_size){
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int ret, sr, channels, bit_rate, frame_size;
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state= (state<<8) + buf[i++];
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ret = avpriv_mpa_decode_header(avctx, state, &sr, &channels, &frame_size, &bit_rate);
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if (ret < 4) {
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if (i > 4)
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s->header_count = -2;
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} else {
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if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
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s->header_count= -3;
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s->header= state;
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s->header_count++;
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s->frame_size = ret-4;
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if (s->header_count > 0) {
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avctx->sample_rate= sr;
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avctx->channels = channels;
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s1->duration = frame_size;
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if (s->no_bitrate || !avctx->bit_rate) {
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s->no_bitrate = 1;
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avctx->bit_rate += (bit_rate - avctx->bit_rate) / s->header_count;
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}
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}
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break;
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}
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}
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}
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}
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pc->state= state;
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if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
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*poutbuf = NULL;
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*poutbuf_size = 0;
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return buf_size;
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}
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*poutbuf = buf;
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*poutbuf_size = buf_size;
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return next;
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}
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AVCodecParser ff_mpegaudio_parser = {
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.codec_ids = { AV_CODEC_ID_MP1, AV_CODEC_ID_MP2, AV_CODEC_ID_MP3 },
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.priv_data_size = sizeof(MpegAudioParseContext),
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.parser_parse = mpegaudio_parse,
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.parser_close = ff_parse_close,
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};
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