summaryrefslogtreecommitdiff
path: root/libavcodec/mlp.h
blob: 8a3e4566a3c75dcf9b32e190b492670c50c1a790 (plain)
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
/*
 * MLP codec common header file
 * Copyright (c) 2007-2008 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
 */

#ifndef AVCODEC_MLP_H
#define AVCODEC_MLP_H

#include <stdint.h>

#include "libavutil/channel_layout.h"

#define SYNC_MLP        0xbb
#define SYNC_TRUEHD     0xba

/** Last possible matrix channel for each codec */
#define MAX_MATRIX_CHANNEL_MLP      5
#define MAX_MATRIX_CHANNEL_TRUEHD   7
/** Maximum number of channels in a valid stream.
 *  MLP   : 5.1 + 2 noise channels -> 8 channels
 *  TrueHD: 7.1                    -> 8 channels
 */
#define MAX_CHANNELS                8

/** Maximum number of matrices used in decoding; most streams have one matrix
 *  per output channel, but some rematrix a channel (usually 0) more than once.
 */
#define MAX_MATRICES_MLP            6
#define MAX_MATRICES_TRUEHD         8
#define MAX_MATRICES                8

/** Maximum number of substreams that can be decoded.
 *  MLP's limit is 2. TrueHD supports at least up to 3.
 */
#define MAX_SUBSTREAMS      4

/** which multiple of 48000 the maximum sample rate is */
#define MAX_RATEFACTOR      4
/** maximum sample frequency seen in files */
#define MAX_SAMPLERATE      (MAX_RATEFACTOR * 48000)

/** maximum number of audio samples within one access unit */
#define MAX_BLOCKSIZE       (40 * MAX_RATEFACTOR)
/** next power of two greater than MAX_BLOCKSIZE */
#define MAX_BLOCKSIZE_POW2  (64 * MAX_RATEFACTOR)

/** number of allowed filters */
#define NUM_FILTERS         2

/** The maximum number of taps in IIR and FIR filters. */
#define MAX_FIR_ORDER       8
#define MAX_IIR_ORDER       4

/** Code that signals end of a stream. */
#define END_OF_STREAM       0xd234d234

#define FIR 0
#define IIR 1

/** filter data */
typedef struct FilterParams {
    uint8_t     order; ///< number of taps in filter
    uint8_t     shift; ///< Right shift to apply to output of filter.

    int32_t     state[MAX_FIR_ORDER];

    int coeff_bits;
    int coeff_shift;
} FilterParams;

/** sample data coding information */
typedef struct ChannelParams {
    FilterParams filter_params[NUM_FILTERS];
    int32_t     coeff[NUM_FILTERS][MAX_FIR_ORDER];

    int16_t     huff_offset;      ///< Offset to apply to residual values.
    int32_t     sign_huff_offset; ///< sign/rounding-corrected version of huff_offset
    uint8_t     codebook;         ///< Which VLC codebook to use to read residuals.
    uint8_t     huff_lsbs;        ///< Size of residual suffix not encoded using VLC.
} ChannelParams;

/** Tables defining the Huffman codes.
 *  There are three entropy coding methods used in MLP (four if you count
 *  "none" as a method). These use the same sequences for codes starting with
 *  00 or 01, but have different codes starting with 1.
 */
extern const uint8_t ff_mlp_huffman_tables[3][18][2];

typedef struct {
    uint8_t channel_occupancy;
    uint8_t group1_channels;
    uint8_t group2_channels;
    uint8_t summary_info;
} ChannelInformation;

/** Tables defining channel information.
 *
 *  Possible channel arrangements are:
 *
 *  (Group 1)   C
 *  (Group 1)   L,  R
 *  (Group 1)   Lf, Rf          /  (Group 2)   S
 *  (Group 1)   Lf, Rf          /  (Group 2)   Ls, Rs
 *  (Group 1)   Lf, Rf          /  (Group 2)   LFE
 *  (Group 1)   Lf, Rf          /  (Group 2)   LFE, S
 *  (Group 1)   Lf, Rf          /  (Group 2)   LFE, Ls, Rs
 *  (Group 1)   Lf, Rf          /  (Group 2)   C
 *  (Group 1)   Lf, Rf          /  (Group 2)   C, S
 *  (Group 1)   Lf, Rf          /  (Group 2)   C, Ls, Rs
 *  (Group 1)   Lf, Rf          /  (Group 2)   C, LFE
 *  (Group 1)   Lf, Rf          /  (Group 2)   C, LFE, S
 *  (Group 1)   Lf, Rf          /  (Group 2)   C, LFE, Ls,  Rs
 *  (Group 1)   Lf, Rf  C       /  (Group 2)   S
 *  (Group 1)   Lf, Rf  C       /  (Group 2)   Ls, Rs
 *  (Group 1)   Lf, Rf  C       /  (Group 2)   LFE
 *  (Group 1)   Lf, Rf  C       /  (Group 2)   LFE, S
 *  (Group 1)   Lf, Rf  C       /  (Group 2)   LFE, Ls, Rs
 *  (Group 1)   Lf, Rf  Ls  Rs  /  (Group 2)   LFE
 *  (Group 1)   Lf, Rf  Ls  Rs  /  (Group 2)   C
 *  (Group 1)   Lf, Rf, Ls, Rs  /  (Group 2)   C, LFE
 */
extern const ChannelInformation ff_mlp_ch_info[21];

#if FF_API_OLD_CHANNEL_LAYOUT
extern const uint64_t ff_mlp_channel_layouts[12];
#endif
extern const AVChannelLayout ff_mlp_ch_layouts[12];

/** MLP uses checksums that seem to be based on the standard CRC algorithm, but
 *  are not (in implementation terms, the table lookup and XOR are reversed).
 *  We can implement this behavior using a standard av_crc on all but the
 *  last element, then XOR that with the last element.
 */
uint8_t  ff_mlp_checksum8 (const uint8_t *buf, unsigned int buf_size);
uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size);

/** Calculate an 8-bit checksum over a restart header -- a non-multiple-of-8
 *  number of bits, starting two bits into the first byte of buf.
 */
uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size);

/** XOR together all the bytes of a buffer.
 *  Does this belong in dspcontext?
 */
uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size);

void ff_mlp_init_crc(void);

/** XOR four bytes into one. */
static inline uint8_t xor_32_to_8(uint32_t value)
{
    value ^= value >> 16;
    value ^= value >>  8;
    return value;
}

typedef enum THDChannelModifier {
    THD_CH_MODIFIER_NOTINDICATED  = 0x0,
    THD_CH_MODIFIER_STEREO        = 0x0, // Stereo (not Dolby Surround)
    THD_CH_MODIFIER_LTRT          = 0x1, // Dolby Surround
    THD_CH_MODIFIER_LBINRBIN      = 0x2, // Dolby Headphone
    THD_CH_MODIFIER_MONO          = 0x3, // Mono or Dual Mono
    THD_CH_MODIFIER_NOTSURROUNDEX = 0x1, // Not Dolby Digital EX
    THD_CH_MODIFIER_SURROUNDEX    = 0x2, // Dolby Digital EX
} THDChannelModifier;

#endif /* AVCODEC_MLP_H */