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adxdec.c
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1 /*
2  * Copyright (c) 2011 Justin Ruggles
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "avformat.h"
28 #include "internal.h"
29 
30 #define BLOCK_SIZE 18
31 #define BLOCK_SAMPLES 32
32 
33 typedef struct ADXDemuxerContext {
36 
38 {
40  AVCodecContext *avctx = s->streams[0]->codec;
41  int ret, size;
42 
43  size = BLOCK_SIZE * avctx->channels;
44 
45  pkt->pos = avio_tell(s->pb);
46  pkt->stream_index = 0;
47 
48  ret = av_get_packet(s->pb, pkt, size);
49  if (ret != size) {
50  av_free_packet(pkt);
51  return ret < 0 ? ret : AVERROR(EIO);
52  }
53  if (AV_RB16(pkt->data) & 0x8000) {
54  av_free_packet(pkt);
55  return AVERROR_EOF;
56  }
57  pkt->size = size;
58  pkt->duration = 1;
59  pkt->pts = (pkt->pos - c->header_size) / size;
60 
61  return 0;
62 }
63 
65 {
67  AVCodecContext *avctx;
68 
69  AVStream *st = avformat_new_stream(s, NULL);
70  if (!st)
71  return AVERROR(ENOMEM);
72  avctx = s->streams[0]->codec;
73 
74  if (avio_rb16(s->pb) != 0x8000)
75  return AVERROR_INVALIDDATA;
76  c->header_size = avio_rb16(s->pb) + 4;
77  avio_seek(s->pb, -4, SEEK_CUR);
78 
79  if (ff_get_extradata(avctx, s->pb, c->header_size) < 0)
80  return AVERROR(ENOMEM);
81 
82  if (avctx->extradata_size < 12) {
83  av_log(s, AV_LOG_ERROR, "Invalid extradata size.\n");
84  return AVERROR_INVALIDDATA;
85  }
86  avctx->sample_rate = AV_RB32(avctx->extradata + 8);
87 
90 
92 
93  return 0;
94 }
95 
97  .name = "adx",
98  .long_name = NULL_IF_CONFIG_SMALL("CRI ADX"),
99  .priv_data_size = sizeof(ADXDemuxerContext),
102  .extensions = "adx",
103  .raw_codec_id = AV_CODEC_ID_ADPCM_ADX,
105 };