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
206
207
208
209
210
211
212
213
214
215
|
/*
* Copyright (c) 2007 Ian Caulfield
*
* 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 <stdint.h>
#include "libavutil/channel_layout.h"
#include "get_bits.h"
#include "mlp_parse.h"
#include "mlp.h"
static const uint8_t mlp_quants[16] = {
16, 20, 24, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
};
static const uint8_t mlp_channels[32] = {
1, 2, 3, 4, 3, 4, 5, 3, 4, 5, 4, 5, 6, 4, 5, 4,
5, 6, 5, 5, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
};
static const uint64_t mlp_layout[32] = {
AV_CH_LAYOUT_MONO,
AV_CH_LAYOUT_STEREO,
AV_CH_LAYOUT_2_1,
AV_CH_LAYOUT_QUAD,
AV_CH_LAYOUT_STEREO|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_2_1|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_SURROUND,
AV_CH_LAYOUT_4POINT0,
AV_CH_LAYOUT_5POINT0_BACK,
AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT1_BACK,
AV_CH_LAYOUT_4POINT0,
AV_CH_LAYOUT_5POINT0_BACK,
AV_CH_LAYOUT_SURROUND|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_4POINT0|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT1_BACK,
AV_CH_LAYOUT_QUAD|AV_CH_LOW_FREQUENCY,
AV_CH_LAYOUT_5POINT0_BACK,
AV_CH_LAYOUT_5POINT1_BACK,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
static const uint8_t thd_chancount[13] = {
// LR C LFE LRs LRvh LRc LRrs Cs Ts LRsd LRw Cvh LFE2
2, 1, 1, 2, 2, 2, 2, 1, 1, 2, 2, 1, 1
};
static const uint64_t thd_layout[13] = {
AV_CH_FRONT_LEFT|AV_CH_FRONT_RIGHT, // LR
AV_CH_FRONT_CENTER, // C
AV_CH_LOW_FREQUENCY, // LFE
AV_CH_SIDE_LEFT|AV_CH_SIDE_RIGHT, // LRs
AV_CH_TOP_FRONT_LEFT|AV_CH_TOP_FRONT_RIGHT, // LRvh
AV_CH_FRONT_LEFT_OF_CENTER|AV_CH_FRONT_RIGHT_OF_CENTER, // LRc
AV_CH_BACK_LEFT|AV_CH_BACK_RIGHT, // LRrs
AV_CH_BACK_CENTER, // Cs
AV_CH_TOP_CENTER, // Ts
AV_CH_SURROUND_DIRECT_LEFT|AV_CH_SURROUND_DIRECT_RIGHT, // LRsd
AV_CH_WIDE_LEFT|AV_CH_WIDE_RIGHT, // LRw
AV_CH_TOP_FRONT_CENTER, // Cvh
AV_CH_LOW_FREQUENCY_2, // LFE2
};
static int mlp_samplerate(int in)
{
if (in == 0xF)
return 0;
return (in & 8 ? 44100 : 48000) << (in & 7) ;
}
static int truehd_channels(int chanmap)
{
int channels = 0, i;
for (i = 0; i < 13; i++)
channels += thd_chancount[i] * ((chanmap >> i) & 1);
return channels;
}
static uint64_t truehd_layout(int chanmap)
{
int i;
uint64_t layout = 0;
for (i = 0; i < 13; i++)
layout |= thd_layout[i] * ((chanmap >> i) & 1);
return layout;
}
static int mlp_get_major_sync_size(const uint8_t * buf, int bufsize)
{
int has_extension, extensions = 0;
int size = 28;
if (bufsize < 28)
return -1;
if (AV_RB32(buf) == 0xf8726fba) {
has_extension = buf[25] & 1;
if (has_extension) {
extensions = buf[26] >> 4;
size += 2 + extensions * 2;
}
}
return size;
}
/** Read a major sync info header - contains high level information about
* the stream - sample rate, channel arrangement etc. Most of this
* information is not actually necessary for decoding, only for playback.
* gb must be a freshly initialized GetBitContext with no bits read.
*/
int ff_mlp_read_major_sync(void *log, MLPHeaderInfo *mh, GetBitContext *gb)
{
int ratebits, channel_arrangement, header_size;
uint16_t checksum;
av_assert1(get_bits_count(gb) == 0);
header_size = mlp_get_major_sync_size(gb->buffer, gb->size_in_bits >> 3);
if (header_size < 0 || gb->size_in_bits < header_size << 3) {
av_log(log, AV_LOG_ERROR, "packet too short, unable to read major sync\n");
return -1;
}
checksum = ff_mlp_checksum16(gb->buffer, header_size - 2);
if (checksum != AV_RL16(gb->buffer+header_size-2)) {
av_log(log, AV_LOG_ERROR, "major sync info header checksum error\n");
return AVERROR_INVALIDDATA;
}
if (get_bits_long(gb, 24) != 0xf8726f) /* Sync words */
return AVERROR_INVALIDDATA;
mh->stream_type = get_bits(gb, 8);
mh->header_size = header_size;
if (mh->stream_type == 0xbb) {
mh->group1_bits = mlp_quants[get_bits(gb, 4)];
mh->group2_bits = mlp_quants[get_bits(gb, 4)];
ratebits = get_bits(gb, 4);
mh->group1_samplerate = mlp_samplerate(ratebits);
mh->group2_samplerate = mlp_samplerate(get_bits(gb, 4));
skip_bits(gb, 11);
mh->channel_arrangement=
channel_arrangement = get_bits(gb, 5);
mh->channels_mlp = mlp_channels[channel_arrangement];
mh->channel_layout_mlp = mlp_layout[channel_arrangement];
} else if (mh->stream_type == 0xba) {
mh->group1_bits = 24; // TODO: Is this information actually conveyed anywhere?
mh->group2_bits = 0;
ratebits = get_bits(gb, 4);
mh->group1_samplerate = mlp_samplerate(ratebits);
mh->group2_samplerate = 0;
skip_bits(gb, 4);
mh->channel_modifier_thd_stream0 = get_bits(gb, 2);
mh->channel_modifier_thd_stream1 = get_bits(gb, 2);
mh->channel_arrangement=
channel_arrangement = get_bits(gb, 5);
mh->channels_thd_stream1 = truehd_channels(channel_arrangement);
mh->channel_layout_thd_stream1 = truehd_layout(channel_arrangement);
mh->channel_modifier_thd_stream2 = get_bits(gb, 2);
channel_arrangement = get_bits(gb, 13);
mh->channels_thd_stream2 = truehd_channels(channel_arrangement);
mh->channel_layout_thd_stream2 = truehd_layout(channel_arrangement);
} else
return AVERROR_INVALIDDATA;
mh->access_unit_size = 40 << (ratebits & 7);
mh->access_unit_size_pow2 = 64 << (ratebits & 7);
skip_bits_long(gb, 48);
mh->is_vbr = get_bits1(gb);
mh->peak_bitrate = (get_bits(gb, 15) * mh->group1_samplerate + 8) >> 4;
mh->num_substreams = get_bits(gb, 4);
skip_bits_long(gb, 4 + (header_size - 17) * 8);
return 0;
}
|
