mirror of
https://github.com/curioustorvald/tsvm.git
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873 lines
35 KiB
JavaScript
873 lines
35 KiB
JavaScript
/*
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mp2dec.js JavaScript MPEG-1 Audio Layer II decoder
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Copyright (C) 2011 Liam Wilson
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see http://www.gnu.org/licenses/.
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*/
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/* Note this is a port of kjmp2 by Martin J. Fiedler: */
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/******************************************************************************
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** kjmp2 -- a minimal MPEG-1 Audio Layer II decoder library **
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*******************************************************************************
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** Copyright (C) 2006 Martin J. Fiedler martin.fiedler@gmx.net **
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** **
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** This software is provided 'as-is', without any express or implied **
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** warranty. In no event will the authors be held liable for any damages **
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** arising from the use of this software. **
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** **
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** Permission is granted to anyone to use this software for any purpose, **
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** including commercial applications, and to alter it and redistribute it **
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** freely, subject to the following restrictions: **
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** 1. The origin of this software must not be misrepresented; you must not **
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** claim that you wrote the original software. If you use this software **
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** in a product, an acknowledgment in the product documentation would **
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** be appreciated but is not required. **
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** 2. Altered source versions must be plainly marked as such, and must not **
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** be misrepresented as being the original software. **
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** 3. This notice may not be removed or altered from any source **
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** distribution. **
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******************************************************************************/
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var frame = null; // ptr
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var STEREO=0;
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// #define JOINT_STEREO 1
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var JOINT_STEREO=1;
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// #define DUAL_CHANNEL 2
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var DUAL_CHANNEL=2;
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// #define MONO 3
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var MONO=3;
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// sample rate table
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// static const int sample_rates[4] = { 44100, 48000, 32000, 0 };
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var sample_rates= [ 44100, 48000, 32000, 0 ];
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// bitrate table
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// static const int bitrates[14] =
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// { 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384 };
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var bitrates =[ 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384 ];
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/*
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// scale factors (24-bit fixed-point)
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static const int scf_value[64] = {
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0x02000000, 0x01965FEA, 0x01428A30, 0x01000000,
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0x00CB2FF5, 0x00A14518, 0x00800000, 0x006597FB,
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0x0050A28C, 0x00400000, 0x0032CBFD, 0x00285146,
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0x00200000, 0x001965FF, 0x001428A3, 0x00100000,
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0x000CB2FF, 0x000A1451, 0x00080000, 0x00065980,
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0x00050A29, 0x00040000, 0x00032CC0, 0x00028514,
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0x00020000, 0x00019660, 0x0001428A, 0x00010000,
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0x0000CB30, 0x0000A145, 0x00008000, 0x00006598,
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0x000050A3, 0x00004000, 0x000032CC, 0x00002851,
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0x00002000, 0x00001966, 0x00001429, 0x00001000,
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0x00000CB3, 0x00000A14, 0x00000800, 0x00000659,
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0x0000050A, 0x00000400, 0x0000032D, 0x00000285,
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0x00000200, 0x00000196, 0x00000143, 0x00000100,
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0x000000CB, 0x000000A1, 0x00000080, 0x00000066,
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0x00000051, 0x00000040, 0x00000033, 0x00000028,
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0x00000020, 0x00000019, 0x00000014, 0
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};
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*/
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// scale factors (24-bit fixed-point)
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var scf_value = [
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0x02000000, 0x01965FEA, 0x01428A30, 0x01000000,
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0x00CB2FF5, 0x00A14518, 0x00800000, 0x006597FB,
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0x0050A28C, 0x00400000, 0x0032CBFD, 0x00285146,
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0x00200000, 0x001965FF, 0x001428A3, 0x00100000,
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0x000CB2FF, 0x000A1451, 0x00080000, 0x00065980,
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0x00050A29, 0x00040000, 0x00032CC0, 0x00028514,
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0x00020000, 0x00019660, 0x0001428A, 0x00010000,
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0x0000CB30, 0x0000A145, 0x00008000, 0x00006598,
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0x000050A3, 0x00004000, 0x000032CC, 0x00002851,
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0x00002000, 0x00001966, 0x00001429, 0x00001000,
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0x00000CB3, 0x00000A14, 0x00000800, 0x00000659,
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0x0000050A, 0x00000400, 0x0000032D, 0x00000285,
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0x00000200, 0x00000196, 0x00000143, 0x00000100,
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0x000000CB, 0x000000A1, 0x00000080, 0x00000066,
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0x00000051, 0x00000040, 0x00000033, 0x00000028,
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0x00000020, 0x00000019, 0x00000014, 0];
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/*
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// synthesis window
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static const int D[512] = {
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0x00000, 0x00000, 0x00000, 0x00000, 0x00000, 0x00000, 0x00000,-0x00001,
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-0x00001,-0x00001,-0x00001,-0x00002,-0x00002,-0x00003,-0x00003,-0x00004,
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-0x00004,-0x00005,-0x00006,-0x00006,-0x00007,-0x00008,-0x00009,-0x0000A,
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-0x0000C,-0x0000D,-0x0000F,-0x00010,-0x00012,-0x00014,-0x00017,-0x00019,
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-0x0001C,-0x0001E,-0x00022,-0x00025,-0x00028,-0x0002C,-0x00030,-0x00034,
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-0x00039,-0x0003E,-0x00043,-0x00048,-0x0004E,-0x00054,-0x0005A,-0x00060,
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-0x00067,-0x0006E,-0x00074,-0x0007C,-0x00083,-0x0008A,-0x00092,-0x00099,
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-0x000A0,-0x000A8,-0x000AF,-0x000B6,-0x000BD,-0x000C3,-0x000C9,-0x000CF,
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0x000D5, 0x000DA, 0x000DE, 0x000E1, 0x000E3, 0x000E4, 0x000E4, 0x000E3,
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0x000E0, 0x000DD, 0x000D7, 0x000D0, 0x000C8, 0x000BD, 0x000B1, 0x000A3,
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0x00092, 0x0007F, 0x0006A, 0x00053, 0x00039, 0x0001D,-0x00001,-0x00023,
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-0x00047,-0x0006E,-0x00098,-0x000C4,-0x000F3,-0x00125,-0x0015A,-0x00190,
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-0x001CA,-0x00206,-0x00244,-0x00284,-0x002C6,-0x0030A,-0x0034F,-0x00396,
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-0x003DE,-0x00427,-0x00470,-0x004B9,-0x00502,-0x0054B,-0x00593,-0x005D9,
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-0x0061E,-0x00661,-0x006A1,-0x006DE,-0x00718,-0x0074D,-0x0077E,-0x007A9,
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-0x007D0,-0x007EF,-0x00808,-0x0081A,-0x00824,-0x00826,-0x0081F,-0x0080E,
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0x007F5, 0x007D0, 0x007A0, 0x00765, 0x0071E, 0x006CB, 0x0066C, 0x005FF,
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0x00586, 0x00500, 0x0046B, 0x003CA, 0x0031A, 0x0025D, 0x00192, 0x000B9,
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-0x0002C,-0x0011F,-0x00220,-0x0032D,-0x00446,-0x0056B,-0x0069B,-0x007D5,
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-0x00919,-0x00A66,-0x00BBB,-0x00D16,-0x00E78,-0x00FDE,-0x01148,-0x012B3,
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-0x01420,-0x0158C,-0x016F6,-0x0185C,-0x019BC,-0x01B16,-0x01C66,-0x01DAC,
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-0x01EE5,-0x02010,-0x0212A,-0x02232,-0x02325,-0x02402,-0x024C7,-0x02570,
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-0x025FE,-0x0266D,-0x026BB,-0x026E6,-0x026ED,-0x026CE,-0x02686,-0x02615,
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-0x02577,-0x024AC,-0x023B2,-0x02287,-0x0212B,-0x01F9B,-0x01DD7,-0x01BDD,
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0x019AE, 0x01747, 0x014A8, 0x011D1, 0x00EC0, 0x00B77, 0x007F5, 0x0043A,
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0x00046,-0x003E5,-0x00849,-0x00CE3,-0x011B4,-0x016B9,-0x01BF1,-0x0215B,
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-0x026F6,-0x02CBE,-0x032B3,-0x038D3,-0x03F1A,-0x04586,-0x04C15,-0x052C4,
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-0x05990,-0x06075,-0x06771,-0x06E80,-0x0759F,-0x07CCA,-0x083FE,-0x08B37,
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-0x09270,-0x099A7,-0x0A0D7,-0x0A7FD,-0x0AF14,-0x0B618,-0x0BD05,-0x0C3D8,
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-0x0CA8C,-0x0D11D,-0x0D789,-0x0DDC9,-0x0E3DC,-0x0E9BD,-0x0EF68,-0x0F4DB,
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-0x0FA12,-0x0FF09,-0x103BD,-0x1082C,-0x10C53,-0x1102E,-0x113BD,-0x116FB,
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-0x119E8,-0x11C82,-0x11EC6,-0x120B3,-0x12248,-0x12385,-0x12467,-0x124EF,
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0x1251E, 0x124F0, 0x12468, 0x12386, 0x12249, 0x120B4, 0x11EC7, 0x11C83,
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0x119E9, 0x116FC, 0x113BE, 0x1102F, 0x10C54, 0x1082D, 0x103BE, 0x0FF0A,
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0x0FA13, 0x0F4DC, 0x0EF69, 0x0E9BE, 0x0E3DD, 0x0DDCA, 0x0D78A, 0x0D11E,
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0x0CA8D, 0x0C3D9, 0x0BD06, 0x0B619, 0x0AF15, 0x0A7FE, 0x0A0D8, 0x099A8,
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0x09271, 0x08B38, 0x083FF, 0x07CCB, 0x075A0, 0x06E81, 0x06772, 0x06076,
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0x05991, 0x052C5, 0x04C16, 0x04587, 0x03F1B, 0x038D4, 0x032B4, 0x02CBF,
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0x026F7, 0x0215C, 0x01BF2, 0x016BA, 0x011B5, 0x00CE4, 0x0084A, 0x003E6,
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-0x00045,-0x00439,-0x007F4,-0x00B76,-0x00EBF,-0x011D0,-0x014A7,-0x01746,
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0x019AE, 0x01BDE, 0x01DD8, 0x01F9C, 0x0212C, 0x02288, 0x023B3, 0x024AD,
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0x02578, 0x02616, 0x02687, 0x026CF, 0x026EE, 0x026E7, 0x026BC, 0x0266E,
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0x025FF, 0x02571, 0x024C8, 0x02403, 0x02326, 0x02233, 0x0212B, 0x02011,
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0x01EE6, 0x01DAD, 0x01C67, 0x01B17, 0x019BD, 0x0185D, 0x016F7, 0x0158D,
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0x01421, 0x012B4, 0x01149, 0x00FDF, 0x00E79, 0x00D17, 0x00BBC, 0x00A67,
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0x0091A, 0x007D6, 0x0069C, 0x0056C, 0x00447, 0x0032E, 0x00221, 0x00120,
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0x0002D,-0x000B8,-0x00191,-0x0025C,-0x00319,-0x003C9,-0x0046A,-0x004FF,
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-0x00585,-0x005FE,-0x0066B,-0x006CA,-0x0071D,-0x00764,-0x0079F,-0x007CF,
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0x007F5, 0x0080F, 0x00820, 0x00827, 0x00825, 0x0081B, 0x00809, 0x007F0,
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0x007D1, 0x007AA, 0x0077F, 0x0074E, 0x00719, 0x006DF, 0x006A2, 0x00662,
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0x0061F, 0x005DA, 0x00594, 0x0054C, 0x00503, 0x004BA, 0x00471, 0x00428,
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0x003DF, 0x00397, 0x00350, 0x0030B, 0x002C7, 0x00285, 0x00245, 0x00207,
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0x001CB, 0x00191, 0x0015B, 0x00126, 0x000F4, 0x000C5, 0x00099, 0x0006F,
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0x00048, 0x00024, 0x00002,-0x0001C,-0x00038,-0x00052,-0x00069,-0x0007E,
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-0x00091,-0x000A2,-0x000B0,-0x000BC,-0x000C7,-0x000CF,-0x000D6,-0x000DC,
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-0x000DF,-0x000E2,-0x000E3,-0x000E3,-0x000E2,-0x000E0,-0x000DD,-0x000D9,
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0x000D5, 0x000D0, 0x000CA, 0x000C4, 0x000BE, 0x000B7, 0x000B0, 0x000A9,
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0x000A1, 0x0009A, 0x00093, 0x0008B, 0x00084, 0x0007D, 0x00075, 0x0006F,
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0x00068, 0x00061, 0x0005B, 0x00055, 0x0004F, 0x00049, 0x00044, 0x0003F,
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0x0003A, 0x00035, 0x00031, 0x0002D, 0x00029, 0x00026, 0x00023, 0x0001F,
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0x0001D, 0x0001A, 0x00018, 0x00015, 0x00013, 0x00011, 0x00010, 0x0000E,
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0x0000D, 0x0000B, 0x0000A, 0x00009, 0x00008, 0x00007, 0x00007, 0x00006,
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0x00005, 0x00005, 0x00004, 0x00004, 0x00003, 0x00003, 0x00002, 0x00002,
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0x00002, 0x00002, 0x00001, 0x00001, 0x00001, 0x00001, 0x00001, 0x00001
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};
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*/
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// synthesis window
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var D= [
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0x00000, 0x00000, 0x00000, 0x00000, 0x00000, 0x00000, 0x00000,-0x00001,
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-0x00001,-0x00001,-0x00001,-0x00002,-0x00002,-0x00003,-0x00003,-0x00004,
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-0x00004,-0x00005,-0x00006,-0x00006,-0x00007,-0x00008,-0x00009,-0x0000A,
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-0x0000C,-0x0000D,-0x0000F,-0x00010,-0x00012,-0x00014,-0x00017,-0x00019,
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-0x0001C,-0x0001E,-0x00022,-0x00025,-0x00028,-0x0002C,-0x00030,-0x00034,
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-0x00039,-0x0003E,-0x00043,-0x00048,-0x0004E,-0x00054,-0x0005A,-0x00060,
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-0x00067,-0x0006E,-0x00074,-0x0007C,-0x00083,-0x0008A,-0x00092,-0x00099,
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-0x000A0,-0x000A8,-0x000AF,-0x000B6,-0x000BD,-0x000C3,-0x000C9,-0x000CF,
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0x000D5, 0x000DA, 0x000DE, 0x000E1, 0x000E3, 0x000E4, 0x000E4, 0x000E3,
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0x000E0, 0x000DD, 0x000D7, 0x000D0, 0x000C8, 0x000BD, 0x000B1, 0x000A3,
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0x00092, 0x0007F, 0x0006A, 0x00053, 0x00039, 0x0001D,-0x00001,-0x00023,
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-0x00047,-0x0006E,-0x00098,-0x000C4,-0x000F3,-0x00125,-0x0015A,-0x00190,
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-0x001CA,-0x00206,-0x00244,-0x00284,-0x002C6,-0x0030A,-0x0034F,-0x00396,
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-0x003DE,-0x00427,-0x00470,-0x004B9,-0x00502,-0x0054B,-0x00593,-0x005D9,
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-0x0061E,-0x00661,-0x006A1,-0x006DE,-0x00718,-0x0074D,-0x0077E,-0x007A9,
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-0x007D0,-0x007EF,-0x00808,-0x0081A,-0x00824,-0x00826,-0x0081F,-0x0080E,
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0x007F5, 0x007D0, 0x007A0, 0x00765, 0x0071E, 0x006CB, 0x0066C, 0x005FF,
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0x00586, 0x00500, 0x0046B, 0x003CA, 0x0031A, 0x0025D, 0x00192, 0x000B9,
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-0x0002C,-0x0011F,-0x00220,-0x0032D,-0x00446,-0x0056B,-0x0069B,-0x007D5,
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-0x00919,-0x00A66,-0x00BBB,-0x00D16,-0x00E78,-0x00FDE,-0x01148,-0x012B3,
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-0x01420,-0x0158C,-0x016F6,-0x0185C,-0x019BC,-0x01B16,-0x01C66,-0x01DAC,
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-0x01EE5,-0x02010,-0x0212A,-0x02232,-0x02325,-0x02402,-0x024C7,-0x02570,
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-0x025FE,-0x0266D,-0x026BB,-0x026E6,-0x026ED,-0x026CE,-0x02686,-0x02615,
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-0x02577,-0x024AC,-0x023B2,-0x02287,-0x0212B,-0x01F9B,-0x01DD7,-0x01BDD,
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0x019AE, 0x01747, 0x014A8, 0x011D1, 0x00EC0, 0x00B77, 0x007F5, 0x0043A,
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0x00046,-0x003E5,-0x00849,-0x00CE3,-0x011B4,-0x016B9,-0x01BF1,-0x0215B,
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-0x026F6,-0x02CBE,-0x032B3,-0x038D3,-0x03F1A,-0x04586,-0x04C15,-0x052C4,
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-0x05990,-0x06075,-0x06771,-0x06E80,-0x0759F,-0x07CCA,-0x083FE,-0x08B37,
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-0x09270,-0x099A7,-0x0A0D7,-0x0A7FD,-0x0AF14,-0x0B618,-0x0BD05,-0x0C3D8,
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-0x0CA8C,-0x0D11D,-0x0D789,-0x0DDC9,-0x0E3DC,-0x0E9BD,-0x0EF68,-0x0F4DB,
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-0x0FA12,-0x0FF09,-0x103BD,-0x1082C,-0x10C53,-0x1102E,-0x113BD,-0x116FB,
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-0x119E8,-0x11C82,-0x11EC6,-0x120B3,-0x12248,-0x12385,-0x12467,-0x124EF,
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0x1251E, 0x124F0, 0x12468, 0x12386, 0x12249, 0x120B4, 0x11EC7, 0x11C83,
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0x119E9, 0x116FC, 0x113BE, 0x1102F, 0x10C54, 0x1082D, 0x103BE, 0x0FF0A,
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0x0FA13, 0x0F4DC, 0x0EF69, 0x0E9BE, 0x0E3DD, 0x0DDCA, 0x0D78A, 0x0D11E,
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0x0CA8D, 0x0C3D9, 0x0BD06, 0x0B619, 0x0AF15, 0x0A7FE, 0x0A0D8, 0x099A8,
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0x09271, 0x08B38, 0x083FF, 0x07CCB, 0x075A0, 0x06E81, 0x06772, 0x06076,
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0x05991, 0x052C5, 0x04C16, 0x04587, 0x03F1B, 0x038D4, 0x032B4, 0x02CBF,
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0x026F7, 0x0215C, 0x01BF2, 0x016BA, 0x011B5, 0x00CE4, 0x0084A, 0x003E6,
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-0x00045,-0x00439,-0x007F4,-0x00B76,-0x00EBF,-0x011D0,-0x014A7,-0x01746,
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0x019AE, 0x01BDE, 0x01DD8, 0x01F9C, 0x0212C, 0x02288, 0x023B3, 0x024AD,
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0x02578, 0x02616, 0x02687, 0x026CF, 0x026EE, 0x026E7, 0x026BC, 0x0266E,
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0x025FF, 0x02571, 0x024C8, 0x02403, 0x02326, 0x02233, 0x0212B, 0x02011,
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0x01EE6, 0x01DAD, 0x01C67, 0x01B17, 0x019BD, 0x0185D, 0x016F7, 0x0158D,
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0x01421, 0x012B4, 0x01149, 0x00FDF, 0x00E79, 0x00D17, 0x00BBC, 0x00A67,
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0x0091A, 0x007D6, 0x0069C, 0x0056C, 0x00447, 0x0032E, 0x00221, 0x00120,
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0x0002D,-0x000B8,-0x00191,-0x0025C,-0x00319,-0x003C9,-0x0046A,-0x004FF,
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-0x00585,-0x005FE,-0x0066B,-0x006CA,-0x0071D,-0x00764,-0x0079F,-0x007CF,
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0x007F5, 0x0080F, 0x00820, 0x00827, 0x00825, 0x0081B, 0x00809, 0x007F0,
|
|
0x007D1, 0x007AA, 0x0077F, 0x0074E, 0x00719, 0x006DF, 0x006A2, 0x00662,
|
|
0x0061F, 0x005DA, 0x00594, 0x0054C, 0x00503, 0x004BA, 0x00471, 0x00428,
|
|
0x003DF, 0x00397, 0x00350, 0x0030B, 0x002C7, 0x00285, 0x00245, 0x00207,
|
|
0x001CB, 0x00191, 0x0015B, 0x00126, 0x000F4, 0x000C5, 0x00099, 0x0006F,
|
|
0x00048, 0x00024, 0x00002,-0x0001C,-0x00038,-0x00052,-0x00069,-0x0007E,
|
|
-0x00091,-0x000A2,-0x000B0,-0x000BC,-0x000C7,-0x000CF,-0x000D6,-0x000DC,
|
|
-0x000DF,-0x000E2,-0x000E3,-0x000E3,-0x000E2,-0x000E0,-0x000DD,-0x000D9,
|
|
0x000D5, 0x000D0, 0x000CA, 0x000C4, 0x000BE, 0x000B7, 0x000B0, 0x000A9,
|
|
0x000A1, 0x0009A, 0x00093, 0x0008B, 0x00084, 0x0007D, 0x00075, 0x0006F,
|
|
0x00068, 0x00061, 0x0005B, 0x00055, 0x0004F, 0x00049, 0x00044, 0x0003F,
|
|
0x0003A, 0x00035, 0x00031, 0x0002D, 0x00029, 0x00026, 0x00023, 0x0001F,
|
|
0x0001D, 0x0001A, 0x00018, 0x00015, 0x00013, 0x00011, 0x00010, 0x0000E,
|
|
0x0000D, 0x0000B, 0x0000A, 0x00009, 0x00008, 0x00007, 0x00007, 0x00006,
|
|
0x00005, 0x00005, 0x00004, 0x00004, 0x00003, 0x00003, 0x00002, 0x00002,
|
|
0x00002, 0x00002, 0x00001, 0x00001, 0x00001, 0x00001, 0x00001, 0x00001];
|
|
|
|
///////////// Table 3-B.2: Possible quantization per subband ///////////////////
|
|
|
|
// quantizer lookup, step 1: bitrate classes
|
|
/*
|
|
static const char quant_lut_step1[2][16] = {
|
|
// 32, 48, 56, 64, 80, 96,112,128,160,192,224,256,320,384 <- bitrate
|
|
{ 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2 }, // mono
|
|
// 16, 24, 28, 32, 40, 48, 56, 64, 80, 96,112,128,160,192 <- BR / chan
|
|
{ 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2 } // stereo
|
|
};
|
|
*/
|
|
var quant_lut_step1= [
|
|
[ 0, 0, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2 ],
|
|
[ 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2 ]];
|
|
/*
|
|
// quantizer lookup, step 2: bitrate class, sample rate -> B2 table idx, sblimit
|
|
#define QUANT_TAB_A (27 | 64) // Table 3-B.2a: high-rate, sblimit = 27
|
|
#define QUANT_TAB_B (30 | 64) // Table 3-B.2b: high-rate, sblimit = 30
|
|
#define QUANT_TAB_C 8 // Table 3-B.2c: low-rate, sblimit = 8
|
|
#define QUANT_TAB_D 12 // Table 3-B.2d: low-rate, sblimit = 12
|
|
*/
|
|
|
|
// quantizer lookup, step 2: bitrate class, sample rate -> B2 table idx, sblimit
|
|
var QUANT_TAB_A= (27 | 64); // Table 3-B.2a: high-rate, sblimit = 27
|
|
var QUANT_TAB_B= (30 | 64); // Table 3-B.2b: high-rate, sblimit = 30
|
|
var QUANT_TAB_C = 8; // Table 3-B.2c: low-rate, sblimit = 8
|
|
var QUANT_TAB_D = 12 ; // Table 3-B.2d: low-rate, sblimit = 12
|
|
/*
|
|
static const char quant_lut_step2[3][4] = {
|
|
// 44.1 kHz, 48 kHz, 32 kHz
|
|
{ QUANT_TAB_C, QUANT_TAB_C, QUANT_TAB_D }, // 32 - 48 kbit/sec/ch
|
|
{ QUANT_TAB_A, QUANT_TAB_A, QUANT_TAB_A }, // 56 - 80 kbit/sec/ch
|
|
{ QUANT_TAB_B, QUANT_TAB_A, QUANT_TAB_B }, // 96+ kbit/sec/ch
|
|
};
|
|
*/
|
|
var quant_lut_step2 = [
|
|
[ QUANT_TAB_C, QUANT_TAB_C, QUANT_TAB_D ],
|
|
[ QUANT_TAB_A, QUANT_TAB_A, QUANT_TAB_A ],
|
|
[ QUANT_TAB_B, QUANT_TAB_A, QUANT_TAB_B ]];
|
|
|
|
/*
|
|
// quantizer lookup, step 3: B2 table, subband -> nbal, row index
|
|
// (upper 4 bits: nbal, lower 4 bits: row index)
|
|
static const char quant_lut_step3[2][32] = {
|
|
// low-rate table (3-B.2c and 3-B.2d)
|
|
{ 0x44,0x44, // SB 0 - 1
|
|
0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34 // SB 2 - 12
|
|
},
|
|
// high-rate table (3-B.2a and 3-B.2b)
|
|
{ 0x43,0x43,0x43, // SB 0 - 2
|
|
0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42, // SB 3 - 10
|
|
0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31, // SB 11 - 22
|
|
0x20,0x20,0x20,0x20,0x20,0x20,0x20 // SB 23 - 29
|
|
}
|
|
};
|
|
*/
|
|
// quantizer lookup, step 3: B2 table, subband -> nbal, row index
|
|
// (upper 4 bits: nbal, lower 4 bits: row index)
|
|
var quant_lut_step3 = [
|
|
[ 0x44,0x44,
|
|
0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34
|
|
],
|
|
[ 0x43,0x43,0x43,
|
|
0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42,
|
|
0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,
|
|
0x20,0x20,0x20,0x20,0x20,0x20,0x20 ]];
|
|
/*
|
|
// quantizer lookup, step 4: table row, allocation[] value -> quant table index
|
|
static const char quant_lut_step4[5][16] = {
|
|
{ 0, 1, 2, 17 },
|
|
{ 0, 1, 2, 3, 4, 5, 6, 17 },
|
|
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17 },
|
|
{ 0, 1, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 },
|
|
{ 0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17 }
|
|
};
|
|
*/
|
|
// quantizer lookup, step 4: table row, allocation[] value -> quant table index
|
|
var quant_lut_step4 = [
|
|
[ 0, 1, 2, 17 ],
|
|
[ 0, 1, 2, 3, 4, 5, 6, 17 ],
|
|
[ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17 ],
|
|
[ 0, 1, 3, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 ],
|
|
[ 0, 1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17 ] ];
|
|
// quantizer specification structure
|
|
/*
|
|
struct quantizer_spec {
|
|
unsigned short nlevels;
|
|
char grouping;
|
|
char cw_bits;
|
|
unsigned short Smul, Sdiv;
|
|
};
|
|
*/
|
|
/*
|
|
Have to change to function;
|
|
// quantizer specification structure
|
|
var quantizer_spec= {
|
|
nlevels: 0,
|
|
grouping: 0,
|
|
cw_bits:0 ,
|
|
Smul: 0, Sdiv:0 };
|
|
*/
|
|
|
|
var quantizer_spec=function(nlevels, grouping, cw_bits , Smul, Sdiv){
|
|
return {
|
|
nlevels: nlevels,
|
|
grouping: grouping,
|
|
cw_bits: cw_bits,
|
|
Smul: Smul,
|
|
Sdiv: Sdiv };
|
|
};
|
|
|
|
/*
|
|
// quantizer table
|
|
static const struct quantizer_spec quantizer_table[17] = {
|
|
{ 3, 1, 5, 0x7FFF, 0xFFFF },
|
|
{ 5, 1, 7, 0x3FFF, 0x0002 },
|
|
{ 7, 0, 3, 0x2AAA, 0x0003 },
|
|
{ 9, 1, 10, 0x1FFF, 0x0002 },
|
|
{ 15, 0, 4, 0x1249, 0xFFFF },
|
|
{ 31, 0, 5, 0x0888, 0x0003 },
|
|
{ 63, 0, 6, 0x0421, 0xFFFF },
|
|
{ 127, 0, 7, 0x0208, 0x0009 },
|
|
{ 255, 0, 8, 0x0102, 0x007F },
|
|
{ 511, 0, 9, 0x0080, 0x0002 },
|
|
{ 1023, 0, 10, 0x0040, 0x0009 },
|
|
{ 2047, 0, 11, 0x0020, 0x0021 },
|
|
{ 4095, 0, 12, 0x0010, 0x0089 },
|
|
{ 8191, 0, 13, 0x0008, 0x0249 },
|
|
{ 16383, 0, 14, 0x0004, 0x0AAB },
|
|
{ 32767, 0, 15, 0x0002, 0x3FFF },
|
|
{ 65535, 0, 16, 0x0001, 0xFFFF }
|
|
};
|
|
*/
|
|
|
|
|
|
// quantizer table
|
|
var quantizer_table =[
|
|
quantizer_spec ( 3, 1, 5, 0x7FFF, 0xFFFF ),
|
|
quantizer_spec ( 5, 1, 7, 0x3FFF, 0x0002 ),
|
|
quantizer_spec ( 7, 0, 3, 0x2AAA, 0x0003 ),
|
|
quantizer_spec ( 9, 1, 10, 0x1FFF, 0x0002 ),
|
|
quantizer_spec ( 15, 0, 4, 0x1249, 0xFFFF ),
|
|
quantizer_spec ( 31, 0, 5, 0x0888, 0x0003 ),
|
|
quantizer_spec ( 63, 0, 6, 0x0421, 0xFFFF ),
|
|
quantizer_spec ( 127, 0, 7, 0x0208, 0x0009 ),
|
|
quantizer_spec ( 255, 0, 8, 0x0102, 0x007F ),
|
|
quantizer_spec ( 511, 0, 9, 0x0080, 0x0002 ),
|
|
quantizer_spec ( 1023, 0, 10, 0x0040, 0x0009 ),
|
|
quantizer_spec ( 2047, 0, 11, 0x0020, 0x0021 ),
|
|
quantizer_spec ( 4095, 0, 12, 0x0010, 0x0089 ),
|
|
quantizer_spec ( 8191, 0, 13, 0x0008, 0x0249 ),
|
|
quantizer_spec ( 16383, 0, 14, 0x0004, 0x0AAB ),
|
|
quantizer_spec ( 32767, 0, 15, 0x0002, 0x3FFF ),
|
|
quantizer_spec ( 65535, 0, 16, 0x0001, 0xFFFF )];
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// STATIC VARIABLES AND FUNCTIONS //
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
/*
|
|
#define KJMP2_MAGIC 0x32706D
|
|
|
|
static int initialized = 0;
|
|
static int bit_window;
|
|
static int bits_in_window;
|
|
static const unsigned char *frame_pos;
|
|
*/
|
|
|
|
|
|
var KJMP2_MAGIC= 0x32706D;
|
|
|
|
var initialized = 0;
|
|
var bit_window;
|
|
var bits_in_window;
|
|
var frame_pos;
|
|
/*
|
|
#define show_bits(bit_count) (bit_window >> (24 - (bit_count)))
|
|
|
|
static int FASTCALL get_bits(int bit_count) {
|
|
int result = show_bits(bit_count);
|
|
bit_window = (bit_window << bit_count) & 0xFFFFFF;
|
|
bits_in_window -= bit_count;
|
|
while (bits_in_window < 16) {
|
|
bit_window |= (*frame_pos++) << (16 - bits_in_window);
|
|
bits_in_window += 8;
|
|
}
|
|
return result;
|
|
}
|
|
*/
|
|
|
|
var show_bits=function(bit_count){return (bit_window >> (24 - (bit_count)))};
|
|
|
|
var get_bits=function(bit_count) {
|
|
var result = show_bits(bit_count);
|
|
bit_window = (bit_window << bit_count) & 0xFFFFFF;
|
|
bits_in_window -= bit_count;
|
|
while (bits_in_window < 16) {
|
|
bit_window = bit_window | (sys.peek(frame + frame_pos++) << (16 - bits_in_window));
|
|
bits_in_window += 8;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// INITIALIZATION //
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
/*
|
|
static int N[64][32]; // N[i][j] as 8-bit fixed-point
|
|
|
|
void kjmp2_init(kjmp2_context_t *mp2) {
|
|
int i, j;
|
|
// check if global initialization is required
|
|
if (!initialized) {
|
|
int *nptr = &N[0][0];
|
|
// compute N[i][j]
|
|
for (i = 0; i < 64; ++i)
|
|
for (j = 0; j < 32; ++j)
|
|
*nptr++ = (int) (256.0 * cos(((16 + i) * ((j << 1) + 1)) * 0.0490873852123405));
|
|
initialized = 1;
|
|
}
|
|
|
|
// perform local initialization: clean the context and put the magic in it
|
|
for (i = 0; i < 2; ++i)
|
|
for (j = 1023; j >= 0; --j)
|
|
mp2->V[i][j] = 0;
|
|
mp2->Voffs = 0;
|
|
mp2->id = KJMP2_MAGIC;
|
|
}
|
|
*/
|
|
|
|
|
|
var N=[];
|
|
(function(){for(var i=0;i<64;i++){N.push([])}})();
|
|
|
|
var kjmp2_init=function(mp2) {
|
|
var i, j;
|
|
// check if global initialization is required
|
|
if (!initialized) {
|
|
var nptr = N;
|
|
// compute N[i][j]
|
|
for (i = 0; i < 64; ++i){
|
|
for (j = 0; j < 32; ++j){
|
|
nptr[i][j] = Math.floor(256.0 * Math.cos(((16 + i) * ((j << 1) + 1)) * 0.0490873852123405));
|
|
}
|
|
}
|
|
initialized = 1;
|
|
}
|
|
|
|
// perform local initialization: clean the context and put the magic in it
|
|
for (i = 0; i < 2; ++i){
|
|
for (j = 1023; j >= 0; --j){
|
|
mp2.V[i][j] = 0;
|
|
};
|
|
};
|
|
mp2.Voffs = 0;
|
|
mp2.id = KJMP2_MAGIC;
|
|
};
|
|
|
|
/*
|
|
int kjmp2_get_sample_rate(const unsigned char *frame) {
|
|
if (!frame)
|
|
return 0;
|
|
if ((frame[0] != 0xFF) // no valid syncword?
|
|
|| (frame[1] != 0xFD) // no MPEG-1 Audio Layer II w/o redundancy?
|
|
|| ((frame[2] - 0x10) >= 0xE0)) // invalid bitrate?
|
|
return 0;
|
|
return sample_rates[(frame[2] >> 2) & 3];
|
|
}
|
|
*/
|
|
|
|
var kjmp2_get_sample_rate=function(frame) {
|
|
if (frame == null){
|
|
return 0;};
|
|
if ((sys.peek(frame) != 0xFF) || (sys.peek(frame +1) != 0xFD) || ((sys.peek(frame +2) - 0x10) >= 0xE0)) {
|
|
return 0;};
|
|
return sample_rates[(sys.peek(frame +2) >> 2) & 3];
|
|
};
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// DECODE HELPER FUNCTIONS //
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
/*
|
|
static const struct quantizer_spec* FASTCALL read_allocation(int sb, int b2_table) {
|
|
int table_idx = quant_lut_step3[b2_table][sb];
|
|
table_idx = quant_lut_step4[table_idx & 15][get_bits(table_idx >> 4)];
|
|
return table_idx ? (&quantizer_table[table_idx - 1]) : 0;
|
|
}
|
|
*/
|
|
|
|
var read_allocation=function(sb, b2_table) {
|
|
var table_idx = quant_lut_step3[b2_table][sb];
|
|
table_idx = quant_lut_step4[table_idx & 15][get_bits(table_idx >> 4)];
|
|
return table_idx ? (quantizer_table[table_idx - 1]) : 0;
|
|
}
|
|
|
|
/*
|
|
static void FASTCALL read_samples(const struct quantizer_spec *q, int scalefactor, int *sample) {
|
|
int idx, adj;
|
|
register int val;
|
|
if (!q) {
|
|
// no bits allocated for this subband
|
|
sample[0] = sample[1] = sample[2] = 0;
|
|
return;
|
|
}
|
|
// resolve scalefactor
|
|
scalefactor = scf_value[scalefactor];
|
|
|
|
// decode samples
|
|
adj = q->nlevels;
|
|
if (q->grouping) {
|
|
// decode grouped samples
|
|
val = get_bits(q->cw_bits);
|
|
sample[0] = val % adj;
|
|
val /= adj;
|
|
sample[1] = val % adj;
|
|
sample[2] = val / adj;
|
|
} else {
|
|
// decode direct samples
|
|
for(idx = 0; idx < 3; ++idx)
|
|
sample[idx] = get_bits(q->cw_bits);
|
|
}
|
|
|
|
// postmultiply samples
|
|
adj = ((adj + 1) >> 1) - 1;
|
|
for (idx = 0; idx < 3; ++idx) {
|
|
// step 1: renormalization to [-1..1]
|
|
val = adj - sample[idx];
|
|
val = (val * q->Smul) + (val / q->Sdiv);
|
|
// step 2: apply scalefactor
|
|
sample[idx] = ( val * (scalefactor >> 12) // upper part
|
|
+ ((val * (scalefactor & 4095) + 2048) >> 12)) // lower part
|
|
>> 12; // scale adjust
|
|
}
|
|
}
|
|
*/
|
|
|
|
|
|
var read_samples=function(q,scalefactor, sample) {
|
|
var idx, adj;
|
|
var val;
|
|
if (!q) {
|
|
// no bits allocated for this subband
|
|
sample[0] = sample[1] = sample[2] = 0;
|
|
return;
|
|
}
|
|
// resolve scalefactor
|
|
scalefactor = scf_value[scalefactor];
|
|
|
|
// decode samples
|
|
adj = q.nlevels;
|
|
if (q.grouping) {
|
|
// decode grouped samples
|
|
val = get_bits(q.cw_bits);
|
|
sample[0] = val % adj;
|
|
val = Math.floor(val/adj);
|
|
sample[1] = val % adj;
|
|
sample[2] = Math.floor(val / adj);
|
|
} else {
|
|
// decode direct samples
|
|
for(idx = 0; idx < 3; ++idx)
|
|
sample[idx] = get_bits(q.cw_bits);
|
|
}
|
|
|
|
// postmultiply samples
|
|
adj = ((adj + 1) >> 1) - 1;
|
|
for (idx = 0; idx < 3; ++idx) {
|
|
// step 1: renormalization to [-1..1]
|
|
val = adj - sample[idx];
|
|
val = (val * q.Smul) + Math.floor(val / q.Sdiv);
|
|
// step 2: apply scalefactor
|
|
sample[idx] = ( val * (scalefactor >> 12) + ((val * (scalefactor & 4095) + 2048) >> 12)) >> 12; // scale adjust
|
|
}
|
|
}
|
|
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
// FRAME DECODE FUNCTION //
|
|
////////////////////////////////////////////////////////////////////////////////
|
|
/*
|
|
static const struct quantizer_spec *allocation[2][32];
|
|
static int scfsi[2][32];
|
|
static int scalefactor[2][32][3];
|
|
static int sample[2][32][3];
|
|
static int U[512];
|
|
*/
|
|
|
|
var allocation=[[],[]];
|
|
var scfsi=[[],[]];
|
|
var scalefactor=[[],[]];
|
|
(function(){
|
|
|
|
for(var j=0;j<2;j++){
|
|
for(var i=0;i<32;i++){
|
|
scalefactor[j][i]=[[],[],[]];
|
|
}
|
|
}
|
|
})();
|
|
var sample=[[],[]];
|
|
(function(){
|
|
|
|
for(var j=0;j<2;j++){
|
|
for(var i=0;i<32;i++){
|
|
sample[j][i]=[[],[],[]];
|
|
}
|
|
}
|
|
})();
|
|
var U=[];
|
|
|
|
var kjmp2_decode_frame=function(mp2,fr,pcm,outL,outR) {
|
|
|
|
let pushSizeL = 0
|
|
let pushSizeR = 0
|
|
function pushL(sampleL) {
|
|
sys.poke(outL + pushSizeL + 0, (sampleL & 255))
|
|
sys.poke(outL + pushSizeL + 1, (sampleL >>> 8))
|
|
pushSizeL += 2
|
|
}
|
|
function pushR(sampleR) {
|
|
sys.poke(outR + pushSizeR + 0, (sampleR & 255))
|
|
sys.poke(outR + pushSizeR + 1, (sampleR >>> 8))
|
|
pushSizeR += 2
|
|
}
|
|
|
|
|
|
if (fr == null) {
|
|
throw Error("Frame is null")
|
|
}
|
|
frame=fr;
|
|
var bit_rate_index_minus1;
|
|
var sampling_frequency;
|
|
var padding_bit;
|
|
var mode;
|
|
var frame_size;
|
|
var bound, sblimit;
|
|
var sb, ch, gr, part, idx, nch, i, j, sum;
|
|
var table_idx;
|
|
// general sanity check
|
|
if (!initialized || !mp2 || (mp2.id !== KJMP2_MAGIC)){
|
|
throw Error("MP2 not initialised")
|
|
};
|
|
// check for valid header: syncword OK, MPEG-Audio Layer 2
|
|
if ((sys.peek(frame) != 0xFF) || ((sys.peek(frame +1) & 0xFE) != 0xFC)){
|
|
throw Error("Invalid header")
|
|
};
|
|
|
|
// set up the bitstream reader
|
|
bit_window = sys.peek(frame +2) << 16;
|
|
bits_in_window = 8;
|
|
frame_pos = 3;
|
|
|
|
// read the rest of the header
|
|
bit_rate_index_minus1 = get_bits(4) - 1;
|
|
if (bit_rate_index_minus1 > 13){
|
|
throw Error("Invalid bit rate") // invalid bit rate or 'free format'
|
|
};
|
|
sampling_frequency = get_bits(2);
|
|
if (sampling_frequency === 3){
|
|
throw Error("Invalid sampling frequency")
|
|
};
|
|
padding_bit = get_bits(1);
|
|
get_bits(1); // discard private_bit
|
|
mode = get_bits(2);
|
|
|
|
// parse the mode_extension, set up the stereo bound
|
|
if (mode === JOINT_STEREO) {
|
|
bound = (get_bits(2) + 1) << 2;
|
|
} else {
|
|
get_bits(2);
|
|
bound = (mode === MONO) ? 0 : 32;
|
|
}
|
|
|
|
// discard the last 4 bits of the header and the CRC value, if present
|
|
get_bits(4);
|
|
if ((sys.peek(frame +1) & 1) == 0)
|
|
get_bits(16);
|
|
|
|
// compute the frame size
|
|
frame_size = Math.floor(144000 * bitrates[bit_rate_index_minus1] / sample_rates[sampling_frequency]) + padding_bit;
|
|
if (!pcm){
|
|
return [frame_size, pushSizeL]; // no decoding
|
|
};
|
|
|
|
// prepare the quantizer table lookups
|
|
table_idx = (mode === MONO) ? 0 : 1;
|
|
table_idx = quant_lut_step1[table_idx][bit_rate_index_minus1];
|
|
table_idx = quant_lut_step2[table_idx][sampling_frequency];
|
|
sblimit = table_idx & 63;
|
|
table_idx >>= 6;
|
|
if (bound > sblimit){
|
|
bound = sblimit;
|
|
};
|
|
// read the allocation information
|
|
for (sb = 0; sb < bound; ++sb){
|
|
for (ch = 0; ch < 2; ++ch){
|
|
allocation[ch][sb] = read_allocation(sb, table_idx);
|
|
};
|
|
};
|
|
|
|
for (sb = bound; sb < sblimit; ++sb){
|
|
allocation[0][sb] = allocation[1][sb] = read_allocation(sb, table_idx);
|
|
};
|
|
|
|
// read scale factor selector information
|
|
nch = (mode === MONO) ? 1 : 2;
|
|
for (sb = 0; sb < sblimit; ++sb) {
|
|
for (ch = 0; ch < nch; ++ch){
|
|
if (allocation[ch][sb]){
|
|
scfsi[ch][sb] = get_bits(2);
|
|
};
|
|
}
|
|
if (mode === MONO){
|
|
scfsi[1][sb] = scfsi[0][sb];
|
|
};
|
|
};
|
|
// read scale factors
|
|
for (sb = 0; sb < sblimit; ++sb) {
|
|
for (ch = 0; ch < nch; ++ch)
|
|
if (allocation[ch][sb]) {
|
|
switch (scfsi[ch][sb]) {
|
|
case 0: scalefactor[ch][sb][0] = get_bits(6);
|
|
scalefactor[ch][sb][1] = get_bits(6);
|
|
scalefactor[ch][sb][2] = get_bits(6);
|
|
break;
|
|
case 1: scalefactor[ch][sb][0] =
|
|
scalefactor[ch][sb][1] = get_bits(6);
|
|
scalefactor[ch][sb][2] = get_bits(6);
|
|
break;
|
|
case 2: scalefactor[ch][sb][0] =
|
|
scalefactor[ch][sb][1] =
|
|
scalefactor[ch][sb][2] = get_bits(6);
|
|
break;
|
|
case 3: scalefactor[ch][sb][0] = get_bits(6);
|
|
scalefactor[ch][sb][1] =
|
|
scalefactor[ch][sb][2] = get_bits(6);
|
|
break;
|
|
}
|
|
}
|
|
if (mode == MONO){
|
|
for (part = 0; part < 3; ++part){
|
|
scalefactor[1][sb][part] = scalefactor[0][sb][part];
|
|
};
|
|
};
|
|
}
|
|
// let ppcm=0;
|
|
// coefficient input and reconstruction
|
|
for (part = 0; part < 3; ++part){
|
|
for (gr = 0; gr < 4; ++gr) {
|
|
|
|
// read the samples
|
|
for (sb = 0; sb < bound; ++sb){
|
|
for (ch = 0; ch < 2; ++ch){
|
|
read_samples(allocation[ch][sb], scalefactor[ch][sb][part], sample[ch][sb]);
|
|
};
|
|
};
|
|
for (sb = bound; sb < sblimit; ++sb) {
|
|
read_samples(allocation[0][sb], scalefactor[0][sb][part], sample[0][sb]);
|
|
|
|
for (idx = 0; idx < 3; ++idx){
|
|
sample[1][sb][idx] = sample[0][sb][idx];
|
|
};
|
|
};
|
|
for (ch = 0; ch < 2; ++ch){
|
|
for (sb = sblimit; sb < 32; ++sb){
|
|
for (idx = 0; idx < 3; ++idx){
|
|
sample[ch][sb][idx] = 0;
|
|
};
|
|
};
|
|
};
|
|
|
|
// synthesis loop
|
|
for (idx = 0; idx < 3; ++idx) {
|
|
// shifting step
|
|
mp2.Voffs = table_idx = (mp2.Voffs - 64) & 1023;
|
|
|
|
for (ch = 0; ch < 2; ++ch) {
|
|
// matrixing
|
|
for (i = 0; i < 64; ++i) {
|
|
sum = 0;
|
|
for (j = 0; j < 32; ++j)
|
|
sum += N[i][j] * sample[ch][j][idx]; // 8b*15b=23b
|
|
// intermediate value is 28 bit (23 + 5), clamp to 14b
|
|
mp2.V[ch][table_idx + i] = (sum + 8192) >> 14;
|
|
}
|
|
|
|
// construction of U
|
|
for (i = 0; i < 8; ++i){
|
|
for (j = 0; j < 32; ++j) {
|
|
U[(i << 6) + j] = mp2.V[ch][(table_idx + (i << 7) + j ) & 1023];
|
|
U[(i << 6) + j + 32] = mp2.V[ch][(table_idx + (i << 7) + j + 96) & 1023];
|
|
};
|
|
};
|
|
// apply window
|
|
for (i = 0; i < 512; ++i){
|
|
U[i] = (U[i] * D[i] + 32) >> 6;
|
|
};
|
|
// output samples
|
|
for (j = 0; j < 32; ++j) {
|
|
sum = 0;
|
|
for (i = 0; i < 16; ++i){
|
|
sum -= U[(i << 5) + j];
|
|
};
|
|
sum = (sum + 8) >> 4;
|
|
if (sum < -32768) {sum = -32768};
|
|
if (sum > 32767) {sum = 32767};
|
|
if (ch == 0) { pushL(sum) }
|
|
if (ch == 1) { pushR(sum) }
|
|
}
|
|
} // end of synthesis channel loop
|
|
} // end of synthesis sub-block loop
|
|
|
|
|
|
|
|
// adjust PCM output pointer: decoded 3 * 32 = 96 stereo samples
|
|
// ppcm += 192;
|
|
|
|
} // decoding of the granule finished
|
|
}
|
|
//;[pushSizeL, pushSizeR] = audio.mp2_synthesisLoop(read_samples, allocation, scalefactor, sblimit, mp2, sample, bound, outL, outR)
|
|
if (pushSizeL != pushSizeR && pushSizeR > 0) {
|
|
throw Error(`Push size mismatch -- U${pushSizeL} != R${pushSizeR}`)
|
|
}
|
|
serial.println(pushSizeL)
|
|
return [frame_size, pushSizeL];
|
|
// return [frame_size, 2304];
|
|
};
|
|
|
|
var kjmp2_make_mp2_state=function(){
|
|
return {id: null, V:[[],[]],
|
|
Voffs: null};
|
|
|
|
};
|
|
|
|
exports={kjmp2_decode_frame: kjmp2_decode_frame ,kjmp2_get_sample_rate: kjmp2_get_sample_rate,kjmp2_init: kjmp2_init, kjmp2_get_sample_rate: kjmp2_get_sample_rate, kjmp2_make_mp2_state: kjmp2_make_mp2_state };
|
|
|