path: root/libavformat/adxdec.c (plain)
blob: a271e2afa80a7e8ca08878c5a373ac98ed7d220c

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 {
34	int header_size;
35	} ADXDemuxerContext;
36
37	static int adx_probe(AVProbeData *p)
38	{
39	int offset;
40	if (AV_RB16(p->buf) != 0x8000)
41	return 0;
42	offset = AV_RB16(&p->buf[2]);
43	if ( offset < 8
44	|| offset > p->buf_size - 4
45	|| memcmp(p->buf + offset - 2, "(c)CRI", 6))
46	return 0;
47	return AVPROBE_SCORE_MAX * 3 / 4;
48	}
49
50	static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
51	{
52	ADXDemuxerContext *c = s->priv_data;
53	AVCodecParameters *par = s->streams[0]->codecpar;
54	int ret, size;
55
56	if (par->channels <= 0) {
57	av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n", par->channels);
58	return AVERROR_INVALIDDATA;
59	}
60
61	size = BLOCK_SIZE * par->channels;
62
63	pkt->pos = avio_tell(s->pb);
64	pkt->stream_index = 0;
65
66	ret = av_get_packet(s->pb, pkt, size);
67	if (ret != size) {
68	av_packet_unref(pkt);
69	return ret < 0 ? ret : AVERROR(EIO);
70	}
71	if (AV_RB16(pkt->data) & 0x8000) {
72	av_packet_unref(pkt);
73	return AVERROR_EOF;
74	}
75	pkt->size = size;
76	pkt->duration = 1;
77	pkt->pts = (pkt->pos - c->header_size) / size;
78
79	return 0;
80	}
81
82	static int adx_read_header(AVFormatContext *s)
83	{
84	ADXDemuxerContext *c = s->priv_data;
85	AVCodecParameters *par;
86
87	AVStream *st = avformat_new_stream(s, NULL);
88	if (!st)
89	return AVERROR(ENOMEM);
90	par = s->streams[0]->codecpar;
91
92	if (avio_rb16(s->pb) != 0x8000)
93	return AVERROR_INVALIDDATA;
94	c->header_size = avio_rb16(s->pb) + 4;
95	avio_seek(s->pb, -4, SEEK_CUR);
96
97	if (ff_get_extradata(s, par, s->pb, c->header_size) < 0)
98	return AVERROR(ENOMEM);
99
100	if (par->extradata_size < 12) {
101	av_log(s, AV_LOG_ERROR, "Invalid extradata size.\n");
102	return AVERROR_INVALIDDATA;
103	}
104	par->channels = AV_RB8 (par->extradata + 7);
105	par->sample_rate = AV_RB32(par->extradata + 8);
106
107	if (par->channels <= 0) {
108	av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n", par->channels);
109	return AVERROR_INVALIDDATA;
110	}
111
112	if (par->sample_rate <= 0) {
113	av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", par->sample_rate);
114	return AVERROR_INVALIDDATA;
115	}
116
117	par->codec_type = AVMEDIA_TYPE_AUDIO;
118	par->codec_id = s->iformat->raw_codec_id;
119	par->bit_rate = (int64_t)par->sample_rate * par->channels * BLOCK_SIZE * 8LL / BLOCK_SAMPLES;
120
121	avpriv_set_pts_info(st, 64, BLOCK_SAMPLES, par->sample_rate);
122
123	return 0;
124	}
125
126	AVInputFormat ff_adx_demuxer = {
127	.name = "adx",
128	.long_name = NULL_IF_CONFIG_SMALL("CRI ADX"),
129	.read_probe = adx_probe,
130	.priv_data_size = sizeof(ADXDemuxerContext),
131	.read_header = adx_read_header,
132	.read_packet = adx_read_packet,
133	.extensions = "adx",
134	.raw_codec_id = AV_CODEC_ID_ADPCM_ADX,
135	.flags = AVFMT_GENERIC_INDEX,
136	};
137