path: root/libavformat/aixdec.c (plain)
blob: cad8a1e116e6a142308f2d8e04962e2706665db6

1	/*
2	* AIX demuxer
3	* Copyright (c) 2016 Paul B Mahol
4	*
5	* This file is part of FFmpeg.
6	*
7	* FFmpeg is free software; you can redistribute it and/or
8	* modify it under the terms of the GNU Lesser General Public
9	* License as published by the Free Software Foundation; either
10	* version 2.1 of the License, or (at your option) any later version.
11	*
12	* FFmpeg is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15	* Lesser General Public License for more details.
16	*
17	* You should have received a copy of the GNU Lesser General Public
18	* License along with FFmpeg; if not, write to the Free Software
19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*/
21
22	#include "libavutil/intreadwrite.h"
23	#include "avformat.h"
24	#include "internal.h"
25
26	static int aix_probe(AVProbeData *p)
27	{
28	if (AV_RL32(p->buf) != MKTAG('A','I','X','F') ||
29	AV_RB32(p->buf + 8) != 0x01000014 ||
30	AV_RB32(p->buf + 12) != 0x00000800)
31	return 0;
32
33	return AVPROBE_SCORE_MAX;
34	}
35
36	static int aix_read_header(AVFormatContext *s)
37	{
38	unsigned nb_streams, first_offset, nb_segments;
39	unsigned stream_list_offset;
40	unsigned segment_list_offset = 0x20;
41	unsigned segment_list_entry_size = 0x10;
42	unsigned size;
43	int i;
44
45	avio_skip(s->pb, 4);
46	first_offset = avio_rb32(s->pb) + 8;
47	avio_skip(s->pb, 16);
48	nb_segments = avio_rb16(s->pb);
49	if (nb_segments == 0)
50	return AVERROR_INVALIDDATA;
51	stream_list_offset = segment_list_offset + segment_list_entry_size * nb_segments + 0x10;
52	if (stream_list_offset >= first_offset)
53	return AVERROR_INVALIDDATA;
54	avio_seek(s->pb, stream_list_offset, SEEK_SET);
55	nb_streams = avio_r8(s->pb);
56	if (nb_streams == 0)
57	return AVERROR_INVALIDDATA;
58	avio_skip(s->pb, 7);
59	for (i = 0; i < nb_streams; i++) {
60	AVStream *st = avformat_new_stream(s, NULL);
61
62	if (!st)
63	return AVERROR(ENOMEM);
64	st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
65	st->codecpar->codec_id = AV_CODEC_ID_ADPCM_ADX;
66	st->codecpar->sample_rate = avio_rb32(s->pb);
67	st->codecpar->channels = avio_r8(s->pb);
68	avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
69	avio_skip(s->pb, 3);
70	}
71
72	avio_seek(s->pb, first_offset, SEEK_SET);
73	for (i = 0; i < nb_streams; i++) {
74	if (avio_rl32(s->pb) != MKTAG('A','I','X','P'))
75	return AVERROR_INVALIDDATA;
76	size = avio_rb32(s->pb);
77	if (size <= 8)
78	return AVERROR_INVALIDDATA;
79	avio_skip(s->pb, 8);
80	ff_get_extradata(s, s->streams[i]->codecpar, s->pb, size - 8);
81	}
82
83	return 0;
84	}
85
86	static int aix_read_packet(AVFormatContext *s, AVPacket *pkt)
87	{
88	unsigned size, index, duration, chunk;
89	int64_t pos;
90	int sequence, ret, i;
91
92	pos = avio_tell(s->pb);
93	if (avio_feof(s->pb))
94	return AVERROR_EOF;
95	chunk = avio_rl32(s->pb);
96	size = avio_rb32(s->pb);
97	if (chunk == MKTAG('A','I','X','E')) {
98	avio_skip(s->pb, size);
99	for (i = 0; i < s->nb_streams; i++) {
100	if (avio_feof(s->pb))
101	return AVERROR_EOF;
102	chunk = avio_rl32(s->pb);
103	size = avio_rb32(s->pb);
104	avio_skip(s->pb, size);
105	}
106	pos = avio_tell(s->pb);
107	chunk = avio_rl32(s->pb);
108	size = avio_rb32(s->pb);
109	}
110
111	if (chunk != MKTAG('A','I','X','P'))
112	return AVERROR_INVALIDDATA;
113	if (size <= 8)
114	return AVERROR_INVALIDDATA;
115	index = avio_r8(s->pb);
116	if (avio_r8(s->pb) != s->nb_streams || index >= s->nb_streams)
117	return AVERROR_INVALIDDATA;
118	duration = avio_rb16(s->pb);
119	sequence = avio_rb32(s->pb);
120	if (sequence < 0) {
121	avio_skip(s->pb, size - 8);
122	return 0;
123	}
124
125	ret = av_get_packet(s->pb, pkt, size - 8);
126	pkt->stream_index = index;
127	pkt->duration = duration;
128	pkt->pos = pos;
129	return ret;
130	}
131
132	AVInputFormat ff_aix_demuxer = {
133	.name = "aix",
134	.long_name = NULL_IF_CONFIG_SMALL("CRI AIX"),
135	.read_probe = aix_probe,
136	.read_header = aix_read_header,
137	.read_packet = aix_read_packet,
138	.extensions = "aix",
139	.flags = AVFMT_GENERIC_INDEX,
140	};
141