LCOV - code coverage report
Current view: top level - libavformat - gsmdec.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 10 35 28.6 %
Date: 2017-12-10 21:22:29 Functions: 1 3 33.3 %

          Line data    Source code
       1             : /*
       2             :  * RAW GSM demuxer
       3             :  * Copyright (c) 2011 Justin Ruggles
       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/channel_layout.h"
      23             : #include "libavutil/mathematics.h"
      24             : #include "libavutil/opt.h"
      25             : #include "avformat.h"
      26             : #include "internal.h"
      27             : 
      28             : #define GSM_BLOCK_SIZE    33
      29             : #define GSM_BLOCK_SAMPLES 160
      30             : #define GSM_SAMPLE_RATE   8000
      31             : 
      32             : typedef struct GSMDemuxerContext {
      33             :     AVClass *class;
      34             :     int sample_rate;
      35             : } GSMDemuxerContext;
      36             : 
      37        6130 : static int gsm_probe(AVProbeData *p)
      38             : {
      39        6130 :     int valid = 0, invalid = 0;
      40        6130 :     uint8_t *b = p->buf;
      41     3897466 :     while (b < p->buf + p->buf_size - 32) {
      42     3885206 :         if ((*b & 0xf0) == 0xd0) {
      43      398510 :             valid++;
      44             :         } else {
      45     3486696 :             invalid++;
      46             :         }
      47     3885206 :         b += 33;
      48             :     }
      49        6130 :     if (valid >> 5 > invalid)
      50           0 :         return AVPROBE_SCORE_EXTENSION + 1;
      51        6130 :     return 0;
      52             : }
      53             : 
      54           0 : static int gsm_read_packet(AVFormatContext *s, AVPacket *pkt)
      55             : {
      56             :     int ret, size;
      57             : 
      58           0 :     size = GSM_BLOCK_SIZE;
      59             : 
      60           0 :     pkt->pos = avio_tell(s->pb);
      61           0 :     pkt->stream_index = 0;
      62             : 
      63           0 :     ret = av_get_packet(s->pb, pkt, size);
      64           0 :     if (ret < GSM_BLOCK_SIZE) {
      65           0 :         av_packet_unref(pkt);
      66           0 :         return ret < 0 ? ret : AVERROR(EIO);
      67             :     }
      68           0 :     pkt->duration = 1;
      69           0 :     pkt->pts      = pkt->pos / GSM_BLOCK_SIZE;
      70             : 
      71           0 :     return 0;
      72             : }
      73             : 
      74           0 : static int gsm_read_header(AVFormatContext *s)
      75             : {
      76           0 :     GSMDemuxerContext *c = s->priv_data;
      77           0 :     AVStream *st = avformat_new_stream(s, NULL);
      78           0 :     if (!st)
      79           0 :         return AVERROR(ENOMEM);
      80             : 
      81           0 :     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
      82           0 :     st->codecpar->codec_id    = s->iformat->raw_codec_id;
      83           0 :     st->codecpar->channels    = 1;
      84           0 :     st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
      85           0 :     st->codecpar->sample_rate = c->sample_rate;
      86           0 :     st->codecpar->bit_rate    = GSM_BLOCK_SIZE * 8 * c->sample_rate / GSM_BLOCK_SAMPLES;
      87             : 
      88           0 :     avpriv_set_pts_info(st, 64, GSM_BLOCK_SAMPLES, GSM_SAMPLE_RATE);
      89             : 
      90           0 :     return 0;
      91             : }
      92             : 
      93             : static const AVOption options[] = {
      94             :     { "sample_rate", "", offsetof(GSMDemuxerContext, sample_rate),
      95             :        AV_OPT_TYPE_INT, {.i64 = GSM_SAMPLE_RATE}, 1, INT_MAX / GSM_BLOCK_SIZE,
      96             :        AV_OPT_FLAG_DECODING_PARAM },
      97             :     { NULL },
      98             : };
      99             : 
     100             : static const AVClass gsm_class = {
     101             :     .class_name = "gsm demuxer",
     102             :     .item_name  = av_default_item_name,
     103             :     .option     = options,
     104             :     .version    = LIBAVUTIL_VERSION_INT,
     105             : };
     106             : 
     107             : AVInputFormat ff_gsm_demuxer = {
     108             :     .name           = "gsm",
     109             :     .long_name      = NULL_IF_CONFIG_SMALL("raw GSM"),
     110             :     .priv_data_size = sizeof(GSMDemuxerContext),
     111             :     .read_probe     = gsm_probe,
     112             :     .read_header    = gsm_read_header,
     113             :     .read_packet    = gsm_read_packet,
     114             :     .flags          = AVFMT_GENERIC_INDEX,
     115             :     .extensions     = "gsm",
     116             :     .raw_codec_id   = AV_CODEC_ID_GSM,
     117             :     .priv_class     = &gsm_class,
     118             : };

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