LCOV - code coverage report
Current view: top level - libavcodec - mpegaudio_parser.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 53 55 96.4 %
Date: 2017-12-17 04:34:43 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/id3v1.h" // for ID3v1_TAG_SIZE
      27             : 
      28             : typedef struct MpegAudioParseContext {
      29             :     ParseContext pc;
      30             :     int frame_size;
      31             :     uint32_t header;
      32             :     int header_count;
      33             :     int no_bitrate;
      34             : } MpegAudioParseContext;
      35             : 
      36             : #define MPA_HEADER_SIZE 4
      37             : 
      38             : /* header + layer + freq + lsf/mpeg25 */
      39             : #define SAME_HEADER_MASK \
      40             :    (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
      41             : 
      42       15197 : 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)
      46             : {
      47       15197 :     MpegAudioParseContext *s = s1->priv_data;
      48       15197 :     ParseContext *pc = &s->pc;
      49       15197 :     uint32_t state= pc->state;
      50             :     int i;
      51       15197 :     int next= END_NOT_FOUND;
      52       15197 :     int flush = !buf_size;
      53             : 
      54       45878 :     for(i=0; i<buf_size; ){
      55       27423 :         if(s->frame_size){
      56       14855 :             int inc= FFMIN(buf_size - i, s->frame_size);
      57       14855 :             i += inc;
      58       14855 :             s->frame_size -= inc;
      59       14855 :             state = 0;
      60             : 
      61       14855 :             if(!s->frame_size){
      62       11939 :                 next= i;
      63       11939 :                 break;
      64             :             }
      65             :         }else{
      66      196330 :             while(i<buf_size){
      67             :                 int ret, sr, channels, bit_rate, frame_size;
      68      183514 :                 enum AVCodecID codec_id = avctx->codec_id;
      69             : 
      70      183514 :                 state= (state<<8) + buf[i++];
      71             : 
      72      183514 :                 ret = ff_mpa_decode_header(state, &sr, &channels, &frame_size, &bit_rate, &codec_id);
      73      183514 :                 if (ret < 4) {
      74      171194 :                     if (i > 4)
      75      134245 :                         s->header_count = -2;
      76             :                 } else {
      77       12320 :                     int header_threshold = avctx->codec_id != AV_CODEC_ID_NONE && avctx->codec_id != codec_id;
      78       12320 :                     if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
      79          29 :                         s->header_count= -3;
      80       12320 :                     s->header= state;
      81       12320 :                     s->header_count++;
      82       12320 :                     s->frame_size = ret-4;
      83             : 
      84       12320 :                     if (s->header_count > header_threshold) {
      85       12034 :                         avctx->sample_rate= sr;
      86       12034 :                         avctx->channels   = channels;
      87       12034 :                         s1->duration      = frame_size;
      88       12034 :                         avctx->codec_id   = codec_id;
      89       12034 :                         if (s->no_bitrate || !avctx->bit_rate) {
      90        7167 :                             s->no_bitrate = 1;
      91        7167 :                             avctx->bit_rate += (bit_rate - avctx->bit_rate) / (s->header_count - header_threshold);
      92             :                         }
      93             :                     }
      94             : 
      95       12320 :                     if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
      96         257 :                         s->frame_size = 0;
      97         257 :                         next = buf_size;
      98       12063 :                     } else if (codec_id == AV_CODEC_ID_MP3ADU) {
      99           0 :                         avpriv_report_missing_feature(avctx,
     100             :                             "MP3ADU full parser");
     101           0 :                         return 0; /* parsers must not return error codes */
     102             :                     }
     103             : 
     104       12320 :                     break;
     105             :                 }
     106             :             }
     107             :         }
     108             :     }
     109             : 
     110       15197 :     pc->state= state;
     111       15197 :     if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
     112        2926 :         *poutbuf = NULL;
     113        2926 :         *poutbuf_size = 0;
     114        2926 :         return buf_size;
     115             :     }
     116             : 
     117       12271 :     if (flush && buf_size >= ID3v1_TAG_SIZE && memcmp(buf, "TAG", 3) == 0) {
     118           5 :         *poutbuf = NULL;
     119           5 :         *poutbuf_size = 0;
     120           5 :         return next;
     121             :     }
     122             : 
     123       12266 :     *poutbuf = buf;
     124       12266 :     *poutbuf_size = buf_size;
     125       12266 :     return next;
     126             : }
     127             : 
     128             : 
     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,
     134             : };

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