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
200
201
202
203
204
205
|
/*
* Copyright (C) 2017 foo86
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "spdif.h"
#define MARKER_16LE 0x72F81F4E
#define MARKER_20LE 0x20876FF0E154
#define MARKER_24LE 0x72F8961F4EA5
#define IS_16LE_MARKER(state) ((state & 0xFFFFFFFF) == MARKER_16LE)
#define IS_20LE_MARKER(state) ((state & 0xF0FFFFF0FFFF) == MARKER_20LE)
#define IS_24LE_MARKER(state) ((state & 0xFFFFFFFFFFFF) == MARKER_24LE)
#define IS_LE_MARKER(state) (IS_16LE_MARKER(state) || IS_20LE_MARKER(state) || IS_24LE_MARKER(state))
static int s337m_get_offset_and_codec(void *avc,
uint64_t state,
int data_type, int data_size,
int *offset, enum AVCodecID *codec)
{
int word_bits;
if (IS_16LE_MARKER(state)) {
word_bits = 16;
} else if (IS_20LE_MARKER(state)) {
data_type >>= 8;
data_size >>= 4;
word_bits = 20;
} else {
data_type >>= 8;
word_bits = 24;
}
if ((data_type & 0x1F) != 0x1C) {
if (avc)
avpriv_report_missing_feature(avc, "Data type %#x in SMPTE 337M", data_type & 0x1F);
return AVERROR_PATCHWELCOME;
}
if (codec)
*codec = AV_CODEC_ID_DOLBY_E;
switch (data_size / word_bits) {
case 3648:
*offset = 1920;
break;
case 3644:
*offset = 2002;
break;
case 3640:
*offset = 2000;
break;
case 3040:
*offset = 1601;
break;
default:
if (avc)
avpriv_report_missing_feature(avc, "Dolby E data size %d in SMPTE 337M", data_size);
return AVERROR_PATCHWELCOME;
}
*offset -= 4;
*offset *= (word_bits + 7 >> 3) * 2;
return 0;
}
static int s337m_probe(const AVProbeData *p)
{
uint64_t state = 0;
int markers[3] = { 0 };
int i, pos, sum, max, data_type, data_size, offset;
uint8_t *buf;
for (pos = 0; pos < p->buf_size; pos++) {
state = (state << 8) | p->buf[pos];
if (!IS_LE_MARKER(state))
continue;
buf = p->buf + pos + 1;
if (IS_16LE_MARKER(state)) {
data_type = AV_RL16(buf );
data_size = AV_RL16(buf + 2);
} else {
data_type = AV_RL24(buf );
data_size = AV_RL24(buf + 3);
}
if (s337m_get_offset_and_codec(NULL, state, data_type, data_size, &offset, NULL))
continue;
i = IS_16LE_MARKER(state) ? 0 : IS_20LE_MARKER(state) ? 1 : 2;
markers[i]++;
pos += IS_16LE_MARKER(state) ? 4 : 6;
pos += offset;
state = 0;
}
sum = max = 0;
for (i = 0; i < FF_ARRAY_ELEMS(markers); i++) {
sum += markers[i];
if (markers[max] < markers[i])
max = i;
}
if (markers[max] > 3 && markers[max] * 4 > sum * 3)
return AVPROBE_SCORE_EXTENSION + 1;
return 0;
}
static int s337m_read_header(AVFormatContext *s)
{
s->ctx_flags |= AVFMTCTX_NOHEADER;
return 0;
}
static void bswap_buf24(uint8_t *data, int size)
{
int i;
for (i = 0; i < size / 3; i++, data += 3)
FFSWAP(uint8_t, data[0], data[2]);
}
static int s337m_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
uint64_t state = 0;
int ret, data_type, data_size, offset;
enum AVCodecID codec;
int64_t pos;
while (!IS_LE_MARKER(state)) {
state = (state << 8) | avio_r8(pb);
if (avio_feof(pb))
return AVERROR_EOF;
}
if (IS_16LE_MARKER(state)) {
data_type = avio_rl16(pb);
data_size = avio_rl16(pb);
} else {
data_type = avio_rl24(pb);
data_size = avio_rl24(pb);
}
pos = avio_tell(pb);
if ((ret = s337m_get_offset_and_codec(s, state, data_type, data_size, &offset, &codec)) < 0)
return ret;
if ((ret = av_new_packet(pkt, offset)) < 0)
return ret;
pkt->pos = pos;
if (avio_read(pb, pkt->data, pkt->size) < pkt->size) {
return AVERROR_EOF;
}
if (IS_16LE_MARKER(state))
ff_spdif_bswap_buf16((uint16_t *)pkt->data, (uint16_t *)pkt->data, pkt->size >> 1);
else
bswap_buf24(pkt->data, pkt->size);
if (!s->nb_streams) {
AVStream *st = avformat_new_stream(s, NULL);
if (!st) {
return AVERROR(ENOMEM);
}
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = codec;
st->need_parsing = AVSTREAM_PARSE_HEADERS;
}
return 0;
}
AVInputFormat ff_s337m_demuxer = {
.name = "s337m",
.long_name = NULL_IF_CONFIG_SMALL("SMPTE 337M"),
.read_probe = s337m_probe,
.read_header = s337m_read_header,
.read_packet = s337m_read_packet,
.flags = AVFMT_GENERIC_INDEX,
};
|
