1 /*
2 * DC STR demuxer
3 * Copyright (c) 2015 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 "avformat.h"
23 #include "internal.h"
24
dcstr_probe(const AVProbeData *p)25 static int dcstr_probe(const AVProbeData *p)
26 {
27 if (p->buf_size < 224 || memcmp(p->buf + 213, "Sega Stream", 11))
28 return 0;
29
30 return AVPROBE_SCORE_MAX;
31 }
32
dcstr_read_header(AVFormatContext *s)33 static int dcstr_read_header(AVFormatContext *s)
34 {
35 unsigned codec, align;
36 int mult;
37 AVStream *st;
38
39 st = avformat_new_stream(s, NULL);
40 if (!st)
41 return AVERROR(ENOMEM);
42
43 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
44 st->codecpar->ch_layout.nb_channels = avio_rl32(s->pb);
45 st->codecpar->sample_rate = avio_rl32(s->pb);
46 if (st->codecpar->sample_rate <= 0)
47 return AVERROR_INVALIDDATA;
48 codec = avio_rl32(s->pb);
49 align = avio_rl32(s->pb);
50 avio_skip(s->pb, 4);
51 st->duration = avio_rl32(s->pb);
52 mult = avio_rl32(s->pb);
53 if (st->codecpar->ch_layout.nb_channels <= 0 || mult <= 0 ||
54 mult > INT_MAX / st->codecpar->ch_layout.nb_channels) {
55 av_log(s, AV_LOG_ERROR, "invalid number of channels %d x %d\n",
56 st->codecpar->ch_layout.nb_channels, mult);
57 return AVERROR_INVALIDDATA;
58 }
59 st->codecpar->ch_layout.nb_channels *= mult;
60 if (!align || align > INT_MAX / st->codecpar->ch_layout.nb_channels)
61 return AVERROR_INVALIDDATA;
62 st->codecpar->block_align = align * st->codecpar->ch_layout.nb_channels;
63
64 switch (codec) {
65 case 4: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_AICA; break;
66 case 16: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
67 default: avpriv_request_sample(s, "codec %X", codec);
68 return AVERROR_PATCHWELCOME;
69 }
70
71 avio_skip(s->pb, 0x800 - avio_tell(s->pb));
72 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
73
74 return 0;
75 }
76
dcstr_read_packet(AVFormatContext *s, AVPacket *pkt)77 static int dcstr_read_packet(AVFormatContext *s, AVPacket *pkt)
78 {
79 AVCodecParameters *par = s->streams[0]->codecpar;
80 return av_get_packet(s->pb, pkt, par->block_align);
81 }
82
83 const AVInputFormat ff_dcstr_demuxer = {
84 .name = "dcstr",
85 .long_name = NULL_IF_CONFIG_SMALL("Sega DC STR"),
86 .read_probe = dcstr_probe,
87 .read_header = dcstr_read_header,
88 .read_packet = dcstr_read_packet,
89 .extensions = "str",
90 .flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK | AVFMT_NOBINSEARCH,
91 };
92