1 /*
2  * AC-3 tables
3  * copyright (c) 2001 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * tables taken directly from the AC-3 spec.
25  */
26 
27 #include "libavutil/channel_layout.h"
28 
29 #include "ac3tab.h"
30 
31 /**
32  * Possible frame sizes.
33  * from ATSC A/52 Table 5.18 Frame Size Code Table.
34  */
35 const uint16_t ff_ac3_frame_size_tab[38][3] = {
36     { 64,   69,   96   },
37     { 64,   70,   96   },
38     { 80,   87,   120  },
39     { 80,   88,   120  },
40     { 96,   104,  144  },
41     { 96,   105,  144  },
42     { 112,  121,  168  },
43     { 112,  122,  168  },
44     { 128,  139,  192  },
45     { 128,  140,  192  },
46     { 160,  174,  240  },
47     { 160,  175,  240  },
48     { 192,  208,  288  },
49     { 192,  209,  288  },
50     { 224,  243,  336  },
51     { 224,  244,  336  },
52     { 256,  278,  384  },
53     { 256,  279,  384  },
54     { 320,  348,  480  },
55     { 320,  349,  480  },
56     { 384,  417,  576  },
57     { 384,  418,  576  },
58     { 448,  487,  672  },
59     { 448,  488,  672  },
60     { 512,  557,  768  },
61     { 512,  558,  768  },
62     { 640,  696,  960  },
63     { 640,  697,  960  },
64     { 768,  835,  1152 },
65     { 768,  836,  1152 },
66     { 896,  975,  1344 },
67     { 896,  976,  1344 },
68     { 1024, 1114, 1536 },
69     { 1024, 1115, 1536 },
70     { 1152, 1253, 1728 },
71     { 1152, 1254, 1728 },
72     { 1280, 1393, 1920 },
73     { 1280, 1394, 1920 },
74 };
75 
76 /**
77  * Map audio coding mode (acmod) to number of full-bandwidth channels.
78  * from ATSC A/52 Table 5.8 Audio Coding Mode
79  */
80 const uint8_t ff_ac3_channels_tab[8] = {
81     2, 1, 2, 3, 3, 4, 4, 5
82 };
83 
84 /**
85  * Table to remap channels from AC-3 order to SMPTE order.
86  * [channel_mode][lfe][ch]
87  */
88 const uint8_t ff_ac3_dec_channel_map[8][2][6] = {
89     COMMON_CHANNEL_MAP
90     { { 0, 1, 2, 3,    }, { 0, 1, 4, 2, 3,   } },
91     { { 0, 2, 1, 3, 4, }, { 0, 2, 1, 5, 3, 4 } },
92 };
93 
94 /* possible frequencies */
95 const int ff_ac3_sample_rate_tab[] = { 48000, 44100, 32000, 0 };
96 
97 /* possible bitrates */
98 const uint16_t ff_ac3_bitrate_tab[19] = {
99     32, 40, 48, 56, 64, 80, 96, 112, 128,
100     160, 192, 224, 256, 320, 384, 448, 512, 576, 640
101 };
102 
103 /**
104  * Table of bin locations for rematrixing bands
105  * reference: Section 7.5.2 Rematrixing : Frequency Band Definitions
106  */
107 const uint8_t ff_ac3_rematrix_band_tab[5] = { 13, 25, 37, 61, 253 };
108 
109 /**
110  * Table E2.16 Default Coupling Banding Structure
111  */
112 const uint8_t ff_eac3_default_cpl_band_struct[18] = {
113     0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1
114 };
115 
116 const uint8_t ff_ac3_bap_tab[64]= {
117     0, 1, 1, 1, 1, 1, 2, 2, 3, 3,
118     3, 4, 4, 5, 5, 6, 6, 6, 6, 7,
119     7, 7, 7, 8, 8, 8, 8, 9, 9, 9,
120     9, 10, 10, 10, 10, 11, 11, 11, 11, 12,
121     12, 12, 12, 13, 13, 13, 13, 14, 14, 14,
122     14, 14, 14, 14, 14, 15, 15, 15, 15, 15,
123     15, 15, 15, 15,
124 };
125 
126 const uint8_t ff_ac3_slow_decay_tab[4]={
127     0x0f, 0x11, 0x13, 0x15,
128 };
129 
130 const uint8_t ff_ac3_fast_decay_tab[4]={
131     0x3f, 0x53, 0x67, 0x7b,
132 };
133 
134 const uint16_t ff_ac3_slow_gain_tab[4]= {
135     0x540, 0x4d8, 0x478, 0x410,
136 };
137 
138 const uint16_t ff_ac3_db_per_bit_tab[4]= {
139     0x000, 0x700, 0x900, 0xb00,
140 };
141 
142 const int16_t ff_ac3_floor_tab[8]= {
143     0x2f0, 0x2b0, 0x270, 0x230, 0x1f0, 0x170, 0x0f0, 0xf800,
144 };
145 
146 const uint16_t ff_ac3_fast_gain_tab[8]= {
147     0x080, 0x100, 0x180, 0x200, 0x280, 0x300, 0x380, 0x400,
148 };
149 
150 const uint64_t ff_eac3_custom_channel_map_locations[16][2] = {
151     { 1, AV_CH_FRONT_LEFT },
152     { 1, AV_CH_FRONT_CENTER },
153     { 1, AV_CH_FRONT_RIGHT },
154     { 1, AV_CH_SIDE_LEFT },
155     { 1, AV_CH_SIDE_RIGHT },
156     { 0, AV_CH_FRONT_LEFT_OF_CENTER | AV_CH_FRONT_RIGHT_OF_CENTER },
157     { 0, AV_CH_BACK_LEFT | AV_CH_BACK_RIGHT },
158     { 0, AV_CH_BACK_CENTER },
159     { 0, AV_CH_TOP_CENTER },
160     { 0, AV_CH_SURROUND_DIRECT_LEFT | AV_CH_SURROUND_DIRECT_RIGHT },
161     { 0, AV_CH_WIDE_LEFT | AV_CH_WIDE_RIGHT },
162     { 0, AV_CH_TOP_FRONT_LEFT | AV_CH_TOP_FRONT_RIGHT},
163     { 0, AV_CH_TOP_FRONT_CENTER },
164     { 0, AV_CH_TOP_BACK_LEFT | AV_CH_TOP_BACK_RIGHT },
165     { 0, AV_CH_LOW_FREQUENCY_2 },
166     { 1, AV_CH_LOW_FREQUENCY },
167 };
168