mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-27 01:42:20 +00:00
7f3a7b5c40
Channel coupling is an optional AC-3 feature that increases quality by combining high frequency information from multiple channels into a single channel. The per-channel high frequency information is sent with less accuracy in both the frequency and time domains. This allows more bits to be used for lower frequencies while preserving enough information to reconstruct the high frequencies.
315 lines
9.8 KiB
C
315 lines
9.8 KiB
C
/*
|
|
* AC-3 tables
|
|
* copyright (c) 2001 Fabrice Bellard
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav 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.
|
|
*
|
|
* Libav 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 Libav; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* tables taken directly from the AC-3 spec.
|
|
*/
|
|
|
|
#include "libavutil/audioconvert.h"
|
|
#include "avcodec.h"
|
|
#include "ac3tab.h"
|
|
|
|
/**
|
|
* Possible frame sizes.
|
|
* from ATSC A/52 Table 5.18 Frame Size Code Table.
|
|
*/
|
|
const uint16_t ff_ac3_frame_size_tab[38][3] = {
|
|
{ 64, 69, 96 },
|
|
{ 64, 70, 96 },
|
|
{ 80, 87, 120 },
|
|
{ 80, 88, 120 },
|
|
{ 96, 104, 144 },
|
|
{ 96, 105, 144 },
|
|
{ 112, 121, 168 },
|
|
{ 112, 122, 168 },
|
|
{ 128, 139, 192 },
|
|
{ 128, 140, 192 },
|
|
{ 160, 174, 240 },
|
|
{ 160, 175, 240 },
|
|
{ 192, 208, 288 },
|
|
{ 192, 209, 288 },
|
|
{ 224, 243, 336 },
|
|
{ 224, 244, 336 },
|
|
{ 256, 278, 384 },
|
|
{ 256, 279, 384 },
|
|
{ 320, 348, 480 },
|
|
{ 320, 349, 480 },
|
|
{ 384, 417, 576 },
|
|
{ 384, 418, 576 },
|
|
{ 448, 487, 672 },
|
|
{ 448, 488, 672 },
|
|
{ 512, 557, 768 },
|
|
{ 512, 558, 768 },
|
|
{ 640, 696, 960 },
|
|
{ 640, 697, 960 },
|
|
{ 768, 835, 1152 },
|
|
{ 768, 836, 1152 },
|
|
{ 896, 975, 1344 },
|
|
{ 896, 976, 1344 },
|
|
{ 1024, 1114, 1536 },
|
|
{ 1024, 1115, 1536 },
|
|
{ 1152, 1253, 1728 },
|
|
{ 1152, 1254, 1728 },
|
|
{ 1280, 1393, 1920 },
|
|
{ 1280, 1394, 1920 },
|
|
};
|
|
|
|
/**
|
|
* Map audio coding mode (acmod) to number of full-bandwidth channels.
|
|
* from ATSC A/52 Table 5.8 Audio Coding Mode
|
|
*/
|
|
const uint8_t ff_ac3_channels_tab[8] = {
|
|
2, 1, 2, 3, 3, 4, 4, 5
|
|
};
|
|
|
|
/**
|
|
* Map audio coding mode (acmod) to channel layout mask.
|
|
*/
|
|
const uint16_t ff_ac3_channel_layout_tab[8] = {
|
|
AV_CH_LAYOUT_STEREO,
|
|
AV_CH_LAYOUT_MONO,
|
|
AV_CH_LAYOUT_STEREO,
|
|
AV_CH_LAYOUT_SURROUND,
|
|
AV_CH_LAYOUT_2_1,
|
|
AV_CH_LAYOUT_4POINT0,
|
|
AV_CH_LAYOUT_2_2,
|
|
AV_CH_LAYOUT_5POINT0
|
|
};
|
|
|
|
#define COMMON_CHANNEL_MAP \
|
|
{ { 0, 1, }, { 0, 1, 2, } },\
|
|
{ { 0, }, { 0, 1, } },\
|
|
{ { 0, 1, }, { 0, 1, 2, } },\
|
|
{ { 0, 2, 1, }, { 0, 2, 1, 3, } },\
|
|
{ { 0, 1, 2, }, { 0, 1, 3, 2, } },\
|
|
{ { 0, 2, 1, 3, }, { 0, 2, 1, 4, 3, } },
|
|
|
|
/**
|
|
* Table to remap channels from SMPTE order to AC-3 order.
|
|
* [channel_mode][lfe][ch]
|
|
*/
|
|
const uint8_t ff_ac3_enc_channel_map[8][2][6] = {
|
|
COMMON_CHANNEL_MAP
|
|
{ { 0, 1, 2, 3, }, { 0, 1, 3, 4, 2, } },
|
|
{ { 0, 2, 1, 3, 4, }, { 0, 2, 1, 4, 5, 3 } },
|
|
};
|
|
|
|
/**
|
|
* Table to remap channels from from AC-3 order to SMPTE order.
|
|
* [channel_mode][lfe][ch]
|
|
*/
|
|
const uint8_t ff_ac3_dec_channel_map[8][2][6] = {
|
|
COMMON_CHANNEL_MAP
|
|
{ { 0, 1, 2, 3, }, { 0, 1, 4, 2, 3, } },
|
|
{ { 0, 2, 1, 3, 4, }, { 0, 2, 1, 5, 3, 4 } },
|
|
};
|
|
|
|
/* possible frequencies */
|
|
const uint16_t ff_ac3_sample_rate_tab[3] = { 48000, 44100, 32000 };
|
|
|
|
/* possible bitrates */
|
|
const uint16_t ff_ac3_bitrate_tab[19] = {
|
|
32, 40, 48, 56, 64, 80, 96, 112, 128,
|
|
160, 192, 224, 256, 320, 384, 448, 512, 576, 640
|
|
};
|
|
|
|
/**
|
|
* Table of bin locations for rematrixing bands
|
|
* reference: Section 7.5.2 Rematrixing : Frequency Band Definitions
|
|
*/
|
|
const uint8_t ff_ac3_rematrix_band_tab[5] = { 13, 25, 37, 61, 253 };
|
|
|
|
/**
|
|
* Table E2.16 Default Coupling Banding Structure
|
|
*/
|
|
const uint8_t ff_eac3_default_cpl_band_struct[18] = {
|
|
0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1
|
|
};
|
|
|
|
/* AC-3 MDCT window */
|
|
|
|
/* MDCT window */
|
|
DECLARE_ALIGNED(16, const int16_t, ff_ac3_window)[AC3_WINDOW_SIZE/2] = {
|
|
4, 7, 12, 16, 21, 28, 34, 42,
|
|
51, 61, 72, 84, 97, 111, 127, 145,
|
|
164, 184, 207, 231, 257, 285, 315, 347,
|
|
382, 419, 458, 500, 544, 591, 641, 694,
|
|
750, 810, 872, 937, 1007, 1079, 1155, 1235,
|
|
1318, 1406, 1497, 1593, 1692, 1796, 1903, 2016,
|
|
2132, 2253, 2379, 2509, 2644, 2783, 2927, 3076,
|
|
3230, 3389, 3552, 3721, 3894, 4072, 4255, 4444,
|
|
4637, 4835, 5038, 5246, 5459, 5677, 5899, 6127,
|
|
6359, 6596, 6837, 7083, 7334, 7589, 7848, 8112,
|
|
8380, 8652, 8927, 9207, 9491, 9778,10069,10363,
|
|
10660,10960,11264,11570,11879,12190,12504,12820,
|
|
13138,13458,13780,14103,14427,14753,15079,15407,
|
|
15735,16063,16392,16720,17049,17377,17705,18032,
|
|
18358,18683,19007,19330,19651,19970,20287,20602,
|
|
20914,21225,21532,21837,22139,22438,22733,23025,
|
|
23314,23599,23880,24157,24430,24699,24964,25225,
|
|
25481,25732,25979,26221,26459,26691,26919,27142,
|
|
27359,27572,27780,27983,28180,28373,28560,28742,
|
|
28919,29091,29258,29420,29577,29729,29876,30018,
|
|
30155,30288,30415,30538,30657,30771,30880,30985,
|
|
31086,31182,31274,31363,31447,31528,31605,31678,
|
|
31747,31814,31877,31936,31993,32046,32097,32145,
|
|
32190,32232,32272,32310,32345,32378,32409,32438,
|
|
32465,32490,32513,32535,32556,32574,32592,32608,
|
|
32623,32636,32649,32661,32671,32681,32690,32698,
|
|
32705,32712,32718,32724,32729,32733,32737,32741,
|
|
32744,32747,32750,32752,32754,32756,32757,32759,
|
|
32760,32761,32762,32763,32764,32764,32765,32765,
|
|
32766,32766,32766,32766,32767,32767,32767,32767,
|
|
32767,32767,32767,32767,32767,32767,32767,32767,
|
|
32767,32767,32767,32767,32767,32767,32767,32767,
|
|
};
|
|
|
|
const uint8_t ff_ac3_log_add_tab[260]= {
|
|
0x40,0x3f,0x3e,0x3d,0x3c,0x3b,0x3a,0x39,0x38,0x37,
|
|
0x36,0x35,0x34,0x34,0x33,0x32,0x31,0x30,0x2f,0x2f,
|
|
0x2e,0x2d,0x2c,0x2c,0x2b,0x2a,0x29,0x29,0x28,0x27,
|
|
0x26,0x26,0x25,0x24,0x24,0x23,0x23,0x22,0x21,0x21,
|
|
0x20,0x20,0x1f,0x1e,0x1e,0x1d,0x1d,0x1c,0x1c,0x1b,
|
|
0x1b,0x1a,0x1a,0x19,0x19,0x18,0x18,0x17,0x17,0x16,
|
|
0x16,0x15,0x15,0x15,0x14,0x14,0x13,0x13,0x13,0x12,
|
|
0x12,0x12,0x11,0x11,0x11,0x10,0x10,0x10,0x0f,0x0f,
|
|
0x0f,0x0e,0x0e,0x0e,0x0d,0x0d,0x0d,0x0d,0x0c,0x0c,
|
|
0x0c,0x0c,0x0b,0x0b,0x0b,0x0b,0x0a,0x0a,0x0a,0x0a,
|
|
0x0a,0x09,0x09,0x09,0x09,0x09,0x08,0x08,0x08,0x08,
|
|
0x08,0x08,0x07,0x07,0x07,0x07,0x07,0x07,0x06,0x06,
|
|
0x06,0x06,0x06,0x06,0x06,0x06,0x05,0x05,0x05,0x05,
|
|
0x05,0x05,0x05,0x05,0x04,0x04,0x04,0x04,0x04,0x04,
|
|
0x04,0x04,0x04,0x04,0x04,0x03,0x03,0x03,0x03,0x03,
|
|
0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x03,0x02,
|
|
0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,
|
|
0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x02,0x01,0x01,
|
|
0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
|
|
0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
|
|
0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,
|
|
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
|
|
};
|
|
|
|
const uint16_t ff_ac3_hearing_threshold_tab[AC3_CRITICAL_BANDS][3]= {
|
|
{ 0x04d0,0x04f0,0x0580 },
|
|
{ 0x04d0,0x04f0,0x0580 },
|
|
{ 0x0440,0x0460,0x04b0 },
|
|
{ 0x0400,0x0410,0x0450 },
|
|
{ 0x03e0,0x03e0,0x0420 },
|
|
{ 0x03c0,0x03d0,0x03f0 },
|
|
{ 0x03b0,0x03c0,0x03e0 },
|
|
{ 0x03b0,0x03b0,0x03d0 },
|
|
{ 0x03a0,0x03b0,0x03c0 },
|
|
{ 0x03a0,0x03a0,0x03b0 },
|
|
{ 0x03a0,0x03a0,0x03b0 },
|
|
{ 0x03a0,0x03a0,0x03b0 },
|
|
{ 0x03a0,0x03a0,0x03a0 },
|
|
{ 0x0390,0x03a0,0x03a0 },
|
|
{ 0x0390,0x0390,0x03a0 },
|
|
{ 0x0390,0x0390,0x03a0 },
|
|
{ 0x0380,0x0390,0x03a0 },
|
|
{ 0x0380,0x0380,0x03a0 },
|
|
{ 0x0370,0x0380,0x03a0 },
|
|
{ 0x0370,0x0380,0x03a0 },
|
|
{ 0x0360,0x0370,0x0390 },
|
|
{ 0x0360,0x0370,0x0390 },
|
|
{ 0x0350,0x0360,0x0390 },
|
|
{ 0x0350,0x0360,0x0390 },
|
|
{ 0x0340,0x0350,0x0380 },
|
|
{ 0x0340,0x0350,0x0380 },
|
|
{ 0x0330,0x0340,0x0380 },
|
|
{ 0x0320,0x0340,0x0370 },
|
|
{ 0x0310,0x0320,0x0360 },
|
|
{ 0x0300,0x0310,0x0350 },
|
|
{ 0x02f0,0x0300,0x0340 },
|
|
{ 0x02f0,0x02f0,0x0330 },
|
|
{ 0x02f0,0x02f0,0x0320 },
|
|
{ 0x02f0,0x02f0,0x0310 },
|
|
{ 0x0300,0x02f0,0x0300 },
|
|
{ 0x0310,0x0300,0x02f0 },
|
|
{ 0x0340,0x0320,0x02f0 },
|
|
{ 0x0390,0x0350,0x02f0 },
|
|
{ 0x03e0,0x0390,0x0300 },
|
|
{ 0x0420,0x03e0,0x0310 },
|
|
{ 0x0460,0x0420,0x0330 },
|
|
{ 0x0490,0x0450,0x0350 },
|
|
{ 0x04a0,0x04a0,0x03c0 },
|
|
{ 0x0460,0x0490,0x0410 },
|
|
{ 0x0440,0x0460,0x0470 },
|
|
{ 0x0440,0x0440,0x04a0 },
|
|
{ 0x0520,0x0480,0x0460 },
|
|
{ 0x0800,0x0630,0x0440 },
|
|
{ 0x0840,0x0840,0x0450 },
|
|
{ 0x0840,0x0840,0x04e0 },
|
|
};
|
|
|
|
const uint8_t ff_ac3_bap_tab[64]= {
|
|
0, 1, 1, 1, 1, 1, 2, 2, 3, 3,
|
|
3, 4, 4, 5, 5, 6, 6, 6, 6, 7,
|
|
7, 7, 7, 8, 8, 8, 8, 9, 9, 9,
|
|
9, 10, 10, 10, 10, 11, 11, 11, 11, 12,
|
|
12, 12, 12, 13, 13, 13, 13, 14, 14, 14,
|
|
14, 14, 14, 14, 14, 15, 15, 15, 15, 15,
|
|
15, 15, 15, 15,
|
|
};
|
|
|
|
const uint8_t ff_ac3_slow_decay_tab[4]={
|
|
0x0f, 0x11, 0x13, 0x15,
|
|
};
|
|
|
|
const uint8_t ff_ac3_fast_decay_tab[4]={
|
|
0x3f, 0x53, 0x67, 0x7b,
|
|
};
|
|
|
|
const uint16_t ff_ac3_slow_gain_tab[4]= {
|
|
0x540, 0x4d8, 0x478, 0x410,
|
|
};
|
|
|
|
const uint16_t ff_ac3_db_per_bit_tab[4]= {
|
|
0x000, 0x700, 0x900, 0xb00,
|
|
};
|
|
|
|
const int16_t ff_ac3_floor_tab[8]= {
|
|
0x2f0, 0x2b0, 0x270, 0x230, 0x1f0, 0x170, 0x0f0, 0xf800,
|
|
};
|
|
|
|
const uint16_t ff_ac3_fast_gain_tab[8]= {
|
|
0x080, 0x100, 0x180, 0x200, 0x280, 0x300, 0x380, 0x400,
|
|
};
|
|
|
|
/**
|
|
* Default channel map for a dependent substream defined by acmod
|
|
*/
|
|
const uint16_t ff_eac3_default_chmap[8] = {
|
|
AC3_CHMAP_L | AC3_CHMAP_R, // FIXME Ch1+Ch2
|
|
AC3_CHMAP_C,
|
|
AC3_CHMAP_L | AC3_CHMAP_R,
|
|
AC3_CHMAP_L | AC3_CHMAP_C | AC3_CHMAP_R,
|
|
AC3_CHMAP_L | AC3_CHMAP_R | AC3_CHMAP_C_SUR,
|
|
AC3_CHMAP_L | AC3_CHMAP_C | AC3_CHMAP_R | AC3_CHMAP_C_SUR,
|
|
AC3_CHMAP_L | AC3_CHMAP_R | AC3_CHMAP_L_SUR | AC3_CHMAP_R_SUR,
|
|
AC3_CHMAP_L | AC3_CHMAP_C | AC3_CHMAP_R | AC3_CHMAP_L_SUR | AC3_CHMAP_R_SUR
|
|
};
|