libavformat/adxdec.c

   1 /*
   2  * Copyright (c) 2011 Justin Ruggles
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file
  23  * CRI ADX demuxer
  24  */
  25
  26 #include "libavutil/intreadwrite.h"
  27 #include "libavcodec/adx.h"
  28 #include "avformat.h"
  29 #include "internal.h"
  30
  31 #define BLOCK_SIZE    18
  32 #define BLOCK_SAMPLES 32
  33
  34 typedef struct ADXDemuxerContext {
  35     int header_size;
  36 } ADXDemuxerContext;
  37
  38 static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
  39 {
  40     ADXDemuxerContext *c = s->priv_data;
  41     AVCodecContext *avctx = s->streams[0]->codec;
  42     int ret, size;
  43
  44     size = BLOCK_SIZE * avctx->channels;
  45
  46     pkt->pos = avio_tell(s->pb);
  47     pkt->stream_index = 0;
  48
  49     ret = av_get_packet(s->pb, pkt, size);
  50     if (ret != size) {
  51         av_free_packet(pkt);
  52         return ret < 0 ? ret : AVERROR(EIO);
  53     }
  54     if (AV_RB16(pkt->data) & 0x8000) {
  55         av_free_packet(pkt);
  56         return AVERROR_EOF;
  57     }
  58     pkt->size     = size;
  59     pkt->duration = 1;
  60     pkt->pts      = (pkt->pos - c->header_size) / size;
  61
  62     return 0;
  63 }
  64
  65 static int adx_read_header(AVFormatContext *s, AVFormatParameters *ap)
  66 {
  67     ADXDemuxerContext *c = s->priv_data;
  68     AVCodecContext *avctx;
  69     int ret;
  70
  71     AVStream *st = avformat_new_stream(s, NULL);
  72     if (!st)
  73         return AVERROR(ENOMEM);
  74     avctx = s->streams[0]->codec;
  75
  76     if (avio_rb16(s->pb) != 0x8000)
  77         return AVERROR_INVALIDDATA;
  78     c->header_size = avio_rb16(s->pb) + 4;
  79     avio_seek(s->pb, -4, SEEK_CUR);
  80
  81     avctx->extradata = av_mallocz(c->header_size + FF_INPUT_BUFFER_PADDING_SIZE);
  82     if (!avctx->extradata)
  83         return AVERROR(ENOMEM);
  84     if (avio_read(s->pb, avctx->extradata, c->header_size) < c->header_size) {
  85         av_freep(&avctx->extradata);
  86         return AVERROR(EIO);
  87     }
  88     avctx->extradata_size = c->header_size;
  89
  90     ret = avpriv_adx_decode_header(avctx, avctx->extradata,
  91                                    avctx->extradata_size, &c->header_size,
  92                                    NULL);
  93     if (ret)
  94         return ret;
  95
  96     st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
  97     st->codec->codec_id    = s->iformat->value;
  98
  99     avpriv_set_pts_info(st, 64, BLOCK_SAMPLES, avctx->sample_rate);
 100
 101     return 0;
 102 }
 103
 104 AVInputFormat ff_adx_demuxer = {
 105     .name           = "adx",
 106     .long_name      = NULL_IF_CONFIG_SMALL("CRI ADX"),
 107     .priv_data_size = sizeof(ADXDemuxerContext),
 108     .read_header    = adx_read_header,
 109     .read_packet    = adx_read_packet,
 110     .extensions     = "adx",
 111     .value          = CODEC_ID_ADPCM_ADX,
 112 };