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 "demux.h"
25 #include "internal.h"
26
aix_probe(const AVProbeData * p)27 static int aix_probe(const AVProbeData *p)
28 {
29 if (AV_RL32(p->buf) != MKTAG('A','I','X','F') ||
30 AV_RB32(p->buf + 8) != 0x01000014 ||
31 AV_RB32(p->buf + 12) != 0x00000800)
32 return 0;
33
34 return AVPROBE_SCORE_MAX;
35 }
36
aix_read_header(AVFormatContext * s)37 static int aix_read_header(AVFormatContext *s)
38 {
39 unsigned nb_streams, first_offset, nb_segments;
40 unsigned stream_list_offset;
41 unsigned segment_list_offset = 0x20;
42 unsigned segment_list_entry_size = 0x10;
43 unsigned size;
44 int i;
45
46 avio_skip(s->pb, 4);
47 first_offset = avio_rb32(s->pb) + 8;
48 avio_skip(s->pb, 16);
49 nb_segments = avio_rb16(s->pb);
50 if (nb_segments == 0)
51 return AVERROR_INVALIDDATA;
52 stream_list_offset = segment_list_offset + segment_list_entry_size * nb_segments + 0x10;
53 if (stream_list_offset >= first_offset)
54 return AVERROR_INVALIDDATA;
55 avio_seek(s->pb, stream_list_offset, SEEK_SET);
56 nb_streams = avio_r8(s->pb);
57 if (nb_streams == 0)
58 return AVERROR_INVALIDDATA;
59 avio_skip(s->pb, 7);
60 for (i = 0; i < nb_streams; i++) {
61 AVStream *st = avformat_new_stream(s, NULL);
62
63 if (!st)
64 return AVERROR(ENOMEM);
65 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
66 st->codecpar->codec_id = AV_CODEC_ID_ADPCM_ADX;
67 st->codecpar->sample_rate = avio_rb32(s->pb);
68 st->codecpar->ch_layout.nb_channels = avio_r8(s->pb);
69 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
70 avio_skip(s->pb, 3);
71 }
72
73 avio_seek(s->pb, first_offset, SEEK_SET);
74 for (i = 0; i < nb_streams; i++) {
75 if (avio_rl32(s->pb) != MKTAG('A','I','X','P'))
76 return AVERROR_INVALIDDATA;
77 size = avio_rb32(s->pb);
78 if (size <= 8)
79 return AVERROR_INVALIDDATA;
80 avio_skip(s->pb, 8);
81 ff_get_extradata(s, s->streams[i]->codecpar, s->pb, size - 8);
82 }
83
84 return 0;
85 }
86
aix_read_packet(AVFormatContext * s,AVPacket * pkt)87 static int aix_read_packet(AVFormatContext *s, AVPacket *pkt)
88 {
89 unsigned size, index, duration, chunk;
90 int64_t pos;
91 int sequence, ret, i;
92
93 pos = avio_tell(s->pb);
94 if (avio_feof(s->pb))
95 return AVERROR_EOF;
96 chunk = avio_rl32(s->pb);
97 size = avio_rb32(s->pb);
98 if (chunk == MKTAG('A','I','X','E')) {
99 avio_skip(s->pb, size);
100 for (i = 0; i < s->nb_streams; i++) {
101 if (avio_feof(s->pb))
102 return AVERROR_EOF;
103 chunk = avio_rl32(s->pb);
104 size = avio_rb32(s->pb);
105 avio_skip(s->pb, size);
106 }
107 pos = avio_tell(s->pb);
108 chunk = avio_rl32(s->pb);
109 size = avio_rb32(s->pb);
110 }
111
112 if (chunk != MKTAG('A','I','X','P'))
113 return AVERROR_INVALIDDATA;
114 if (size <= 8)
115 return AVERROR_INVALIDDATA;
116 index = avio_r8(s->pb);
117 if (avio_r8(s->pb) != s->nb_streams || index >= s->nb_streams)
118 return AVERROR_INVALIDDATA;
119 duration = avio_rb16(s->pb);
120 sequence = avio_rb32(s->pb);
121 if (sequence < 0) {
122 avio_skip(s->pb, size - 8);
123 return 0;
124 }
125
126 ret = av_get_packet(s->pb, pkt, size - 8);
127 pkt->stream_index = index;
128 pkt->duration = duration;
129 pkt->pos = pos;
130 return ret;
131 }
132
133 const AVInputFormat ff_aix_demuxer = {
134 .name = "aix",
135 .long_name = NULL_IF_CONFIG_SMALL("CRI AIX"),
136 .read_probe = aix_probe,
137 .read_header = aix_read_header,
138 .read_packet = aix_read_packet,
139 .extensions = "aix",
140 .flags = AVFMT_GENERIC_INDEX,
141 };
142