LCOV - code coverage report
Current view: top level - src/libavformat - ac3dec.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 48 49 98.0 %
Date: 2017-09-22 00:04:37 Functions: 3 3 100.0 %

          Line data    Source code
       1             : /*
       2             :  * RAW AC-3 and E-AC-3 demuxer
       3             :  * Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : #include "libavutil/crc.h"
      23             : #include "libavcodec/ac3_parser.h"
      24             : #include "avformat.h"
      25             : #include "rawdec.h"
      26             : 
      27       12068 : static int ac3_eac3_probe(AVProbeData *p, enum AVCodecID expected_codec_id)
      28             : {
      29       12068 :     int max_frames, first_frames = 0, frames;
      30             :     const uint8_t *buf, *buf2, *end;
      31       12068 :     AC3HeaderInfo *phdr = NULL;
      32             :     GetBitContext gbc;
      33       12068 :     enum AVCodecID codec_id = AV_CODEC_ID_AC3;
      34             : 
      35       12068 :     max_frames = 0;
      36       12068 :     buf = p->buf;
      37       12068 :     end = buf + p->buf_size;
      38             : 
      39   253927476 :     for(; buf < end; buf++) {
      40   253915408 :         if(buf > p->buf && !(buf[0] == 0x0B && buf[1] == 0x77)
      41   253900786 :                         && !(buf[0] == 0x77 && buf[1] == 0x0B) )
      42   253895252 :             continue;
      43       20156 :         buf2 = buf;
      44             : 
      45       44552 :         for(frames = 0; buf2 < end; frames++) {
      46             :             uint8_t buf3[4096];
      47             :             int i;
      48       22172 :             if(!memcmp(buf2, "\x1\x10\0\0\0\0\0\0", 8))
      49           0 :                 buf2+=16;
      50       22172 :             if (buf[0] == 0x77 && buf[1] == 0x0B) {
      51       27680 :                 for(i=0; i<8; i+=2) {
      52       22144 :                     buf3[i  ] = buf2[i+1];
      53       22144 :                     buf3[i+1] = buf2[i  ];
      54             :                 }
      55        5536 :                 init_get_bits(&gbc, buf3, 54);
      56             :             }else
      57       16636 :                 init_get_bits(&gbc, buf2, 54);
      58       22172 :             if(avpriv_ac3_parse_header(&gbc, &phdr) < 0)
      59       35000 :                 break;
      60        7224 :             if(buf2 + phdr->frame_size > end)
      61         584 :                 break;
      62        6640 :             if (buf[0] == 0x77 && buf[1] == 0x0B) {
      63        3560 :                 av_assert0(phdr->frame_size <= sizeof(buf3));
      64     2030636 :                 for(i=8; i<phdr->frame_size; i+=2) {
      65     2027076 :                     buf3[i  ] = buf2[i+1];
      66     2027076 :                     buf3[i+1] = buf2[i  ];
      67             :                 }
      68             :             }
      69        6640 :             if(av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, gbc.buffer + 2, phdr->frame_size - 2))
      70        4520 :                 break;
      71        2120 :             if (phdr->bitstream_id > 10)
      72         514 :                 codec_id = AV_CODEC_ID_EAC3;
      73        2120 :             buf2 += phdr->frame_size;
      74             :         }
      75       20156 :         max_frames = FFMAX(max_frames, frames);
      76       20156 :         if(buf == p->buf)
      77       12068 :             first_frames = frames;
      78             :     }
      79       12068 :     av_freep(&phdr);
      80       12068 :     if(codec_id != expected_codec_id) return 0;
      81             :     // keep this in sync with mp3 probe, both need to avoid
      82             :     // issues with MPEG-files!
      83        6034 :     if   (first_frames>=7) return AVPROBE_SCORE_EXTENSION + 1;
      84        6017 :     else if(max_frames>200)return AVPROBE_SCORE_EXTENSION;
      85        6017 :     else if(max_frames>=4) return AVPROBE_SCORE_EXTENSION/2;
      86        6001 :     else if(max_frames>=1) return 1;
      87        5971 :     else                   return 0;
      88             : }
      89             : 
      90             : #if CONFIG_AC3_DEMUXER
      91        6034 : static int ac3_probe(AVProbeData *p)
      92             : {
      93        6034 :     return ac3_eac3_probe(p, AV_CODEC_ID_AC3);
      94             : }
      95             : 
      96             : AVInputFormat ff_ac3_demuxer = {
      97             :     .name           = "ac3",
      98             :     .long_name      = NULL_IF_CONFIG_SMALL("raw AC-3"),
      99             :     .read_probe     = ac3_probe,
     100             :     .read_header    = ff_raw_audio_read_header,
     101             :     .read_packet    = ff_raw_read_partial_packet,
     102             :     .flags= AVFMT_GENERIC_INDEX,
     103             :     .extensions = "ac3",
     104             :     .raw_codec_id   = AV_CODEC_ID_AC3,
     105             : };
     106             : #endif
     107             : 
     108             : #if CONFIG_EAC3_DEMUXER
     109        6034 : static int eac3_probe(AVProbeData *p)
     110             : {
     111        6034 :     return ac3_eac3_probe(p, AV_CODEC_ID_EAC3);
     112             : }
     113             : 
     114             : AVInputFormat ff_eac3_demuxer = {
     115             :     .name           = "eac3",
     116             :     .long_name      = NULL_IF_CONFIG_SMALL("raw E-AC-3"),
     117             :     .read_probe     = eac3_probe,
     118             :     .read_header    = ff_raw_audio_read_header,
     119             :     .read_packet    = ff_raw_read_partial_packet,
     120             :     .flags          = AVFMT_GENERIC_INDEX,
     121             :     .extensions     = "eac3",
     122             :     .raw_codec_id   = AV_CODEC_ID_EAC3,
     123             : };
     124             : #endif

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