LCOV - code coverage report
Current view: top level - libavformat - aacdec.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 63 72 87.5 %
Date: 2017-12-12 11:08:38 Functions: 3 3 100.0 %

          Line data    Source code
       1             : /*
       2             :  * raw ADTS AAC demuxer
       3             :  * Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
       4             :  * Copyright (c) 2009 Robert Swain ( rob opendot cl )
       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 "libavutil/intreadwrite.h"
      24             : #include "avformat.h"
      25             : #include "internal.h"
      26             : #include "id3v1.h"
      27             : #include "apetag.h"
      28             : 
      29             : #define ADTS_HEADER_SIZE 7
      30             : 
      31        6130 : static int adts_aac_probe(AVProbeData *p)
      32             : {
      33        6130 :     int max_frames = 0, first_frames = 0;
      34             :     int fsize, frames;
      35        6130 :     const uint8_t *buf0 = p->buf;
      36             :     const uint8_t *buf2;
      37             :     const uint8_t *buf;
      38        6130 :     const uint8_t *end = buf0 + p->buf_size - 7;
      39             : 
      40        6130 :     buf = buf0;
      41             : 
      42    85643720 :     for (; buf < end; buf = buf2 + 1) {
      43    85637590 :         buf2 = buf;
      44             : 
      45    85651074 :         for (frames = 0; buf2 < end; frames++) {
      46    85649329 :             uint32_t header = AV_RB16(buf2);
      47    85649329 :             if ((header & 0xFFF6) != 0xFFF0) {
      48    85635692 :                 if (buf != buf0) {
      49             :                     // Found something that isn't an ADTS header, starting
      50             :                     // from a position other than the start of the buffer.
      51             :                     // Discard the count we've accumulated so far since it
      52             :                     // probably was a false positive.
      53    85629590 :                     frames = 0;
      54             :                 }
      55    85635692 :                 break;
      56             :             }
      57       13637 :             fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
      58       13637 :             if (fsize < 7)
      59         153 :                 break;
      60       13484 :             fsize = FFMIN(fsize, end - buf2);
      61       13484 :             buf2 += fsize;
      62             :         }
      63    85637590 :         max_frames = FFMAX(max_frames, frames);
      64    85637590 :         if (buf == buf0)
      65        6130 :             first_frames = frames;
      66             :     }
      67             : 
      68        6130 :     if (first_frames >= 3)
      69          26 :         return AVPROBE_SCORE_EXTENSION + 1;
      70        6104 :     else if (max_frames > 100)
      71           0 :         return AVPROBE_SCORE_EXTENSION;
      72        6104 :     else if (max_frames >= 3)
      73           0 :         return AVPROBE_SCORE_EXTENSION / 2;
      74        6104 :     else if (first_frames >= 1)
      75           2 :         return 1;
      76             :     else
      77        6102 :         return 0;
      78             : }
      79             : 
      80          29 : static int adts_aac_read_header(AVFormatContext *s)
      81             : {
      82             :     AVStream *st;
      83             :     uint16_t state;
      84             : 
      85          29 :     st = avformat_new_stream(s, NULL);
      86          29 :     if (!st)
      87           0 :         return AVERROR(ENOMEM);
      88             : 
      89          29 :     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
      90          29 :     st->codecpar->codec_id   = s->iformat->raw_codec_id;
      91          29 :     st->need_parsing         = AVSTREAM_PARSE_FULL_RAW;
      92             : 
      93          29 :     ff_id3v1_read(s);
      94          58 :     if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) &&
      95          29 :         !av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
      96          28 :         int64_t cur = avio_tell(s->pb);
      97          28 :         ff_ape_parse_tag(s);
      98          28 :         avio_seek(s->pb, cur, SEEK_SET);
      99             :     }
     100             : 
     101             :     // skip data until the first ADTS frame is found
     102          29 :     state = avio_r8(s->pb);
     103         311 :     while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
     104         282 :         state = (state << 8) | avio_r8(s->pb);
     105         282 :         if ((state >> 4) != 0xFFF)
     106         253 :             continue;
     107          29 :         avio_seek(s->pb, -2, SEEK_CUR);
     108          29 :         break;
     109             :     }
     110          29 :     if ((state >> 4) != 0xFFF)
     111           0 :         return AVERROR_INVALIDDATA;
     112             : 
     113             :     // LCM of all possible ADTS sample rates
     114          29 :     avpriv_set_pts_info(st, 64, 1, 28224000);
     115             : 
     116          29 :     return 0;
     117             : }
     118             : 
     119        5522 : static int adts_aac_read_packet(AVFormatContext *s, AVPacket *pkt)
     120             : {
     121             :     int ret, fsize;
     122             : 
     123        5522 :     ret = av_get_packet(s->pb, pkt, ADTS_HEADER_SIZE);
     124        5522 :     if (ret < 0)
     125          41 :         return ret;
     126        5481 :     if (ret < ADTS_HEADER_SIZE) {
     127           0 :         av_packet_unref(pkt);
     128           0 :         return AVERROR(EIO);
     129             :     }
     130             : 
     131        5481 :     if ((AV_RB16(pkt->data) >> 4) != 0xfff) {
     132           2 :         av_packet_unref(pkt);
     133           2 :         return AVERROR_INVALIDDATA;
     134             :     }
     135             : 
     136        5479 :     fsize = (AV_RB32(pkt->data + 3) >> 13) & 0x1FFF;
     137        5479 :     if (fsize < ADTS_HEADER_SIZE) {
     138           0 :         av_packet_unref(pkt);
     139           0 :         return AVERROR_INVALIDDATA;
     140             :     }
     141             : 
     142        5479 :     ret = av_append_packet(s->pb, pkt, fsize - ADTS_HEADER_SIZE);
     143        5479 :     if (ret < 0)
     144           0 :         av_packet_unref(pkt);
     145             : 
     146        5479 :     return ret;
     147             : }
     148             : 
     149             : AVInputFormat ff_aac_demuxer = {
     150             :     .name         = "aac",
     151             :     .long_name    = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
     152             :     .read_probe   = adts_aac_probe,
     153             :     .read_header  = adts_aac_read_header,
     154             :     .read_packet  = adts_aac_read_packet,
     155             :     .flags        = AVFMT_GENERIC_INDEX,
     156             :     .extensions   = "aac",
     157             :     .mime_type    = "audio/aac,audio/aacp,audio/x-aac",
     158             :     .raw_codec_id = AV_CODEC_ID_AAC,
     159             : };

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