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 "demux.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
adx_probe(const AVProbeData *p)38 static int adx_probe(const AVProbeData *p)
39 {
40 int offset;
41 if (AV_RB16(p->buf) != 0x8000)
42 return 0;
43 offset = AV_RB16(&p->buf[2]);
44 if ( offset < 8
45 || offset > p->buf_size - 4
46 || memcmp(p->buf + offset - 2, "(c)CRI", 6))
47 return 0;
48 return AVPROBE_SCORE_MAX * 3 / 4;
49 }
50
adx_read_packet(AVFormatContext *s, AVPacket *pkt)51 static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
52 {
53 ADXDemuxerContext *c = s->priv_data;
54 AVCodecParameters *par = s->streams[0]->codecpar;
55 int ret, size;
56
57 if (avio_feof(s->pb))
58 return AVERROR_EOF;
59
60 if (par->ch_layout.nb_channels <= 0) {
61 av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n", par->ch_layout.nb_channels);
62 return AVERROR_INVALIDDATA;
63 }
64
65 size = BLOCK_SIZE * par->ch_layout.nb_channels;
66
67 pkt->pos = avio_tell(s->pb);
68 pkt->stream_index = 0;
69
70 ret = av_get_packet(s->pb, pkt, size * 128);
71 if (ret < 0)
72 return ret;
73 if ((ret % size) && ret >= size) {
74 size = ret - (ret % size);
75 av_shrink_packet(pkt, size);
76 pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
77 } else if (ret < size) {
78 return AVERROR(EIO);
79 } else {
80 size = ret;
81 }
82
83 pkt->duration = size / (BLOCK_SIZE * par->ch_layout.nb_channels);
84 pkt->pts = (pkt->pos - c->header_size) / (BLOCK_SIZE * par->ch_layout.nb_channels);
85
86 return 0;
87 }
88
adx_read_header(AVFormatContext *s)89 static int adx_read_header(AVFormatContext *s)
90 {
91 ADXDemuxerContext *c = s->priv_data;
92 AVCodecParameters *par;
93 int ret;
94 int channels;
95
96 AVStream *st = avformat_new_stream(s, NULL);
97 if (!st)
98 return AVERROR(ENOMEM);
99 par = s->streams[0]->codecpar;
100
101 if (avio_rb16(s->pb) != 0x8000)
102 return AVERROR_INVALIDDATA;
103 c->header_size = avio_rb16(s->pb) + 4;
104 avio_seek(s->pb, -4, SEEK_CUR);
105
106 if ((ret = ff_get_extradata(s, par, s->pb, c->header_size)) < 0)
107 return ret;
108
109 if (par->extradata_size < 12) {
110 av_log(s, AV_LOG_ERROR, "Invalid extradata size.\n");
111 return AVERROR_INVALIDDATA;
112 }
113 channels = AV_RB8 (par->extradata + 7);
114 par->sample_rate = AV_RB32(par->extradata + 8);
115
116 if (channels <= 0) {
117 av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n", channels);
118 return AVERROR_INVALIDDATA;
119 }
120
121 if (par->sample_rate <= 0) {
122 av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", par->sample_rate);
123 return AVERROR_INVALIDDATA;
124 }
125
126 par->ch_layout.nb_channels = channels;
127 par->codec_type = AVMEDIA_TYPE_AUDIO;
128 par->codec_id = s->iformat->raw_codec_id;
129 par->bit_rate = (int64_t)par->sample_rate * par->ch_layout.nb_channels * BLOCK_SIZE * 8LL / BLOCK_SAMPLES;
130
131 avpriv_set_pts_info(st, 64, BLOCK_SAMPLES, par->sample_rate);
132
133 return 0;
134 }
135
136 const AVInputFormat ff_adx_demuxer = {
137 .name = "adx",
138 .long_name = NULL_IF_CONFIG_SMALL("CRI ADX"),
139 .read_probe = adx_probe,
140 .priv_data_size = sizeof(ADXDemuxerContext),
141 .read_header = adx_read_header,
142 .read_packet = adx_read_packet,
143 .extensions = "adx",
144 .raw_codec_id = AV_CODEC_ID_ADPCM_ADX,
145 .flags = AVFMT_GENERIC_INDEX,
146 };
147