1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/*
* 8088flex TMV file demuxer
* Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* 8088flex TMV file demuxer
* @author Daniel Verkamp
* @see http://www.oldskool.org/pc/8088_Corruption
*/
#include "libavutil/channel_layout.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.h"
enum {
TMV_PADDING = 0x01,
TMV_STEREO = 0x02,
};
#define TMV_TAG MKTAG('T', 'M', 'A', 'V')
typedef struct TMVContext {
unsigned audio_chunk_size;
unsigned video_chunk_size;
unsigned padding;
unsigned stream_index;
} TMVContext;
#define TMV_HEADER_SIZE 12
#define PROBE_MIN_SAMPLE_RATE 5000
#define PROBE_MAX_FPS 120
#define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS)
static int tmv_probe(AVProbeData *p)
{
if (AV_RL32(p->buf) == TMV_TAG &&
AV_RL16(p->buf+4) >= PROBE_MIN_SAMPLE_RATE &&
AV_RL16(p->buf+6) >= PROBE_MIN_AUDIO_SIZE &&
!p->buf[8] && // compression method
p->buf[9] && // char cols
p->buf[10]) // char rows
return AVPROBE_SCORE_MAX /
((p->buf[9] == 40 && p->buf[10] == 25) ? 1 : 4);
return 0;
}
static int tmv_read_header(AVFormatContext *s)
{
TMVContext *tmv = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *vst, *ast;
AVRational fps;
unsigned comp_method, char_cols, char_rows, features;
if (avio_rl32(pb) != TMV_TAG)
return -1;
if (!(vst = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
if (!(ast = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
ast->codecpar->sample_rate = avio_rl16(pb);
if (!ast->codecpar->sample_rate) {
av_log(s, AV_LOG_ERROR, "invalid sample rate\n");
return -1;
}
tmv->audio_chunk_size = avio_rl16(pb);
if (!tmv->audio_chunk_size) {
av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n");
return -1;
}
comp_method = avio_r8(pb);
if (comp_method) {
av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n",
comp_method);
return -1;
}
char_cols = avio_r8(pb);
char_rows = avio_r8(pb);
tmv->video_chunk_size = char_cols * char_rows * 2;
features = avio_r8(pb);
if (features & ~(TMV_PADDING | TMV_STEREO)) {
av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n",
features & ~(TMV_PADDING | TMV_STEREO));
return -1;
}
ast->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
ast->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
if (features & TMV_STEREO) {
ast->codecpar->channels = 2;
ast->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
} else {
ast->codecpar->channels = 1;
ast->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
}
ast->codecpar->bits_per_coded_sample = 8;
ast->codecpar->bit_rate = ast->codecpar->sample_rate *
ast->codecpar->bits_per_coded_sample;
avpriv_set_pts_info(ast, 32, 1, ast->codecpar->sample_rate);
fps.num = ast->codecpar->sample_rate * ast->codecpar->channels;
fps.den = tmv->audio_chunk_size;
av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL);
vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
vst->codecpar->codec_id = AV_CODEC_ID_TMV;
vst->codecpar->format = AV_PIX_FMT_PAL8;
vst->codecpar->width = char_cols * 8;
vst->codecpar->height = char_rows * 8;
avpriv_set_pts_info(vst, 32, fps.den, fps.num);
if (features & TMV_PADDING)
tmv->padding =
((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) -
(tmv->video_chunk_size + tmv->audio_chunk_size);
vst->codecpar->bit_rate = ((tmv->video_chunk_size + tmv->padding) *
fps.num * 8) / fps.den;
return 0;
}
static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt)
{
TMVContext *tmv = s->priv_data;
AVIOContext *pb = s->pb;
int ret, pkt_size = tmv->stream_index ?
tmv->audio_chunk_size : tmv->video_chunk_size;
if (pb->eof_reached)
return AVERROR_EOF;
ret = av_get_packet(pb, pkt, pkt_size);
if (tmv->stream_index)
avio_skip(pb, tmv->padding);
pkt->stream_index = tmv->stream_index;
tmv->stream_index ^= 1;
pkt->flags |= AV_PKT_FLAG_KEY;
return ret;
}
static int tmv_read_seek(AVFormatContext *s, int stream_index,
int64_t timestamp, int flags)
{
TMVContext *tmv = s->priv_data;
int64_t pos;
if (stream_index)
return -1;
pos = timestamp *
(tmv->audio_chunk_size + tmv->video_chunk_size + tmv->padding);
if (avio_seek(s->pb, pos + TMV_HEADER_SIZE, SEEK_SET) < 0)
return -1;
tmv->stream_index = 0;
return 0;
}
AVInputFormat ff_tmv_demuxer = {
.name = "tmv",
.long_name = NULL_IF_CONFIG_SMALL("8088flex TMV"),
.priv_data_size = sizeof(TMVContext),
.read_probe = tmv_probe,
.read_header = tmv_read_header,
.read_packet = tmv_read_packet,
.read_seek = tmv_read_seek,
.flags = AVFMT_GENERIC_INDEX,
};
|
