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
|
/*
* RAW DTS demuxer
* Copyright (c) 2008 Benjamin Larsson
*
* 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 "libavcodec/bytestream.h"
#include "libavcodec/dca.h"
#include "libavcodec/dca_syncwords.h"
#include "libavcodec/get_bits.h"
#include "avformat.h"
#include "rawdec.h"
static int dts_probe(AVProbeData *p)
{
const uint8_t *buf, *bufp;
uint32_t state = -1;
int markers[4*16] = {0};
int sum, max, i;
int64_t diff = 0;
uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
buf = p->buf + FFMIN(4096, p->buf_size);
for(; buf < (p->buf+p->buf_size)-2; buf+=2) {
int marker, sample_blocks, sample_rate, sr_code, framesize;
int lfe;
GetBitContext gb;
bufp = buf;
state = (state << 16) | bytestream_get_be16(&bufp);
if (buf - p->buf >= 4)
diff += FFABS(((int16_t)AV_RL16(buf)) - (int16_t)AV_RL16(buf-4));
/* regular bitstream */
if (state == DCA_SYNCWORD_CORE_BE)
marker = 0;
else if (state == DCA_SYNCWORD_CORE_LE)
marker = 1;
/* 14 bits big-endian bitstream */
else if (state == DCA_SYNCWORD_CORE_14B_BE &&
(bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
marker = 2;
/* 14 bits little-endian bitstream */
else if (state == DCA_SYNCWORD_CORE_14B_LE &&
(bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007)
marker = 3;
else
continue;
if (avpriv_dca_convert_bitstream(buf-2, 12, hdr, 12) < 0)
continue;
init_get_bits(&gb, hdr, 96);
skip_bits_long(&gb, 39);
sample_blocks = get_bits(&gb, 7) + 1;
if (sample_blocks < 8)
continue;
framesize = get_bits(&gb, 14) + 1;
if (framesize < 95)
continue;
skip_bits(&gb, 6);
sr_code = get_bits(&gb, 4);
sample_rate = avpriv_dca_sample_rates[sr_code];
if (sample_rate == 0)
continue;
get_bits(&gb, 5);
if (get_bits(&gb, 1))
continue;
skip_bits_long(&gb, 9);
lfe = get_bits(&gb, 2);
if (lfe > 2)
continue;
marker += 4* sr_code;
markers[marker] ++;
}
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 && p->buf_size / markers[max] < 32*1024 &&
markers[max] * 4 > sum * 3 &&
diff / p->buf_size > 200)
return AVPROBE_SCORE_EXTENSION + 1;
return 0;
}
AVInputFormat ff_dts_demuxer = {
.name = "dts",
.long_name = NULL_IF_CONFIG_SMALL("raw DTS"),
.read_probe = dts_probe,
.read_header = ff_raw_audio_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags = AVFMT_GENERIC_INDEX,
.extensions = "dts",
.raw_codec_id = AV_CODEC_ID_DTS,
};
|
