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
|
/*
* 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/get_bits.h"
#include "libavcodec/dca.h"
#include "avformat.h"
#include "rawdec.h"
#define DCA_MARKER_14B_BE 0x1FFFE800
#define DCA_MARKER_14B_LE 0xFF1F00E8
#define DCA_MARKER_RAW_BE 0x7FFE8001
#define DCA_MARKER_RAW_LE 0xFE7F0180
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_MARKER_RAW_BE)
marker = 0;
else if (state == DCA_MARKER_RAW_LE)
marker = 1;
/* 14 bits big-endian bitstream */
else if (state == DCA_MARKER_14B_BE &&
(bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
marker = 2;
/* 14 bits little-endian bitstream */
else if (state == DCA_MARKER_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,
};
|
