LCOV - code coverage report
Current view: top level - libavcodec - mpegaudio_parser.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 54 59 91.5 %
Date: 2018-05-20 11:54:08 Functions: 1 1 100.0 %

          Line data    Source code
       1             : /*
       2             :  * MPEG Audio parser
       3             :  * Copyright (c) 2003 Fabrice Bellard
       4             :  * Copyright (c) 2003 Michael Niedermayer
       5             :  *
       6             :  * This file is part of FFmpeg.
       7             :  *
       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.
      12             :  *
      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.
      17             :  *
      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
      21             :  */
      22             : 
      23             : #include "parser.h"
      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
      28             : 
      29             : typedef struct MpegAudioParseContext {
      30             :     ParseContext pc;
      31             :     int frame_size;
      32             :     uint32_t header;
      33             :     int header_count;
      34             :     int no_bitrate;
      35             : } MpegAudioParseContext;
      36             : 
      37             : #define MPA_HEADER_SIZE 4
      38             : 
      39             : /* header + layer + freq + lsf/mpeg25 */
      40             : #define SAME_HEADER_MASK \
      41             :    (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
      42             : 
      43       15247 : 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)
      47             : {
      48       15247 :     MpegAudioParseContext *s = s1->priv_data;
      49       15247 :     ParseContext *pc = &s->pc;
      50       15247 :     uint32_t state= pc->state;
      51             :     int i;
      52       15247 :     int next= END_NOT_FOUND;
      53       15247 :     int flush = !buf_size;
      54             : 
      55       46027 :     for(i=0; i<buf_size; ){
      56       27515 :         if(s->frame_size){
      57       14904 :             int inc= FFMIN(buf_size - i, s->frame_size);
      58       14904 :             i += inc;
      59       14904 :             s->frame_size -= inc;
      60       14904 :             state = 0;
      61             : 
      62       14904 :             if(!s->frame_size){
      63       11982 :                 next= i;
      64       11982 :                 break;
      65             :             }
      66             :         }else{
      67      196545 :             while(i<buf_size){
      68             :                 int ret, sr, channels, bit_rate, frame_size;
      69      183686 :                 enum AVCodecID codec_id = avctx->codec_id;
      70             : 
      71      183686 :                 state= (state<<8) + buf[i++];
      72             : 
      73      183686 :                 ret = ff_mpa_decode_header(state, &sr, &channels, &frame_size, &bit_rate, &codec_id);
      74      183686 :                 if (ret < 4) {
      75      171323 :                     if (i > 4)
      76      134245 :                         s->header_count = -2;
      77             :                 } else {
      78       12363 :                     int header_threshold = avctx->codec_id != AV_CODEC_ID_NONE && avctx->codec_id != codec_id;
      79       12363 :                     if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
      80          29 :                         s->header_count= -3;
      81       12363 :                     s->header= state;
      82       12363 :                     s->header_count++;
      83       12363 :                     s->frame_size = ret-4;
      84             : 
      85       12363 :                     if (s->header_count > header_threshold) {
      86       12077 :                         avctx->sample_rate= sr;
      87       12077 :                         avctx->channels   = channels;
      88       12077 :                         s1->duration      = frame_size;
      89       12077 :                         avctx->codec_id   = codec_id;
      90       12077 :                         if (s->no_bitrate || !avctx->bit_rate) {
      91        7210 :                             s->no_bitrate = 1;
      92        7210 :                             avctx->bit_rate += (bit_rate - avctx->bit_rate) / (s->header_count - header_threshold);
      93             :                         }
      94             :                     }
      95             : 
      96       12363 :                     if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
      97         257 :                         s->frame_size = 0;
      98         257 :                         next = buf_size;
      99       12106 :                     } else if (codec_id == AV_CODEC_ID_MP3ADU) {
     100           0 :                         avpriv_report_missing_feature(avctx,
     101             :                             "MP3ADU full parser");
     102           0 :                         return 0; /* parsers must not return error codes */
     103             :                     }
     104             : 
     105       12363 :                     break;
     106             :                 }
     107             :             }
     108             :         }
     109             :     }
     110             : 
     111       15247 :     pc->state= state;
     112       15247 :     if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
     113        2932 :         *poutbuf = NULL;
     114        2932 :         *poutbuf_size = 0;
     115        2932 :         return buf_size;
     116             :     }
     117             : 
     118       12315 :     if (flush && buf_size >= ID3v1_TAG_SIZE && memcmp(buf, "TAG", 3) == 0) {
     119           5 :         *poutbuf = NULL;
     120           5 :         *poutbuf_size = 0;
     121           5 :         return next;
     122             :     }
     123             : 
     124       12310 :     if (flush && buf_size >= APE_TAG_FOOTER_BYTES && memcmp(buf, APE_TAG_PREAMBLE, 8) == 0) {
     125           0 :         *poutbuf = NULL;
     126           0 :         *poutbuf_size = 0;
     127           0 :         return next;
     128             :     }
     129             : 
     130       12310 :     *poutbuf = buf;
     131       12310 :     *poutbuf_size = buf_size;
     132       12310 :     return next;
     133             : }
     134             : 
     135             : 
     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,
     141             : };

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