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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 "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 {
37 
39 {
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 
66 {
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  if (ff_get_extradata(avctx, s->pb, c->header_size) < 0)
82  return AVERROR(ENOMEM);
83 
84  ret = avpriv_adx_decode_header(avctx, avctx->extradata,
85  avctx->extradata_size, &c->header_size,
86  NULL);
87  if (ret)
88  return ret;
89 
92 
94 
95  return 0;
96 }
97 
99  .name = "adx",
100  .long_name = NULL_IF_CONFIG_SMALL("CRI ADX"),
101  .priv_data_size = sizeof(ADXDemuxerContext),
104  .extensions = "adx",
105  .raw_codec_id = AV_CODEC_ID_ADPCM_ADX,
107 };