1 /*
2 * SVS demuxer
3 * Copyright (c) 2020 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/channel_layout.h"
23 #include "libavutil/intreadwrite.h"
24 #include "avformat.h"
25 #include "internal.h"
26
svs_probe(const AVProbeData * p)27 static int svs_probe(const AVProbeData *p)
28 {
29 if (p->buf_size < 32)
30 return 0;
31
32 if (memcmp(p->buf, "SVS\00", 4))
33 return 0;
34
35 if (AV_RL32(p->buf + 16) == 0)
36 return 0;
37
38 return AVPROBE_SCORE_MAX / 3;
39 }
40
svs_read_header(AVFormatContext * s)41 static int svs_read_header(AVFormatContext *s)
42 {
43 AVStream *st;
44 uint32_t pitch;
45
46 st = avformat_new_stream(s, NULL);
47 if (!st)
48 return AVERROR(ENOMEM);
49
50 avio_skip(s->pb, 16);
51 pitch = avio_rl32(s->pb);
52 avio_skip(s->pb, 12);
53
54 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
55 st->codecpar->codec_id = AV_CODEC_ID_ADPCM_PSX;
56 st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
57 st->codecpar->sample_rate = av_rescale_rnd(pitch, 48000, 4096, AV_ROUND_INF);
58 st->codecpar->block_align = 32;
59 st->start_time = 0;
60 if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)
61 st->duration = av_get_audio_frame_duration2(st->codecpar,
62 avio_size(s->pb) - 32);
63
64 avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
65
66 return 0;
67 }
68
svs_read_packet(AVFormatContext * s,AVPacket * pkt)69 static int svs_read_packet(AVFormatContext *s, AVPacket *pkt)
70 {
71 int ret;
72
73 if (avio_feof(s->pb))
74 return AVERROR_EOF;
75
76 ret = av_get_packet(s->pb, pkt, 32 * 256);
77 if (ret != 32 * 256) {
78 if (ret < 0)
79 return ret;
80 pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
81 }
82 pkt->stream_index = 0;
83
84 return ret;
85 }
86
87 const AVInputFormat ff_svs_demuxer = {
88 .name = "svs",
89 .long_name = NULL_IF_CONFIG_SMALL("Square SVS"),
90 .read_probe = svs_probe,
91 .read_header = svs_read_header,
92 .read_packet = svs_read_packet,
93 .extensions = "svs",
94 };
95