JSMpeg.Decoder.MP2Audio = (function(){ "use strict"; // Based on kjmp2 by Martin J. Fiedler // http://keyj.emphy.de/kjmp2/ var MP2 = function(options) { JSMpeg.Decoder.Base.call(this, options); this.onDecodeCallback = options.onAudioDecode; var bufferSize = options.audioBufferSize || 128*1024; var bufferMode = options.streaming ? JSMpeg.BitBuffer.MODE.EVICT : JSMpeg.BitBuffer.MODE.EXPAND; this.bits = new JSMpeg.BitBuffer(bufferSize, bufferMode); this.left = new Float32Array(1152); this.right = new Float32Array(1152); this.sampleRate = 44100; this.D = new Float32Array(1024); this.D.set(MP2.SYNTHESIS_WINDOW, 0); this.D.set(MP2.SYNTHESIS_WINDOW, 512); this.V = new Float32Array(1024); this.U = new Int32Array(32); this.VPos = 0; this.allocation = [new Array(32), new Array(32)]; this.scaleFactorInfo = [new Uint8Array(32), new Uint8Array(32)]; this.scaleFactor = [new Array(32), new Array(32)]; this.sample = [new Array(32), new Array(32)]; for (var j = 0; j < 2; j++) { for (var i = 0; i < 32; i++) { this.scaleFactor[j][i] = [0, 0, 0]; this.sample[j][i] = [0, 0, 0]; } } }; MP2.prototype = Object.create(JSMpeg.Decoder.Base.prototype); MP2.prototype.constructor = MP2; MP2.prototype.decode = function() { var startTime = JSMpeg.Now(); var pos = this.bits.index >> 3; if (pos >= this.bits.byteLength) { return false; } var decoded = this.decodeFrame(this.left, this.right); this.bits.index = (pos + decoded) << 3; if (!decoded) { return false; } if (this.destination) { this.destination.play(this.sampleRate, this.left, this.right); } this.advanceDecodedTime(this.left.length / this.sampleRate); var elapsedTime = JSMpeg.Now() - startTime; if (this.onDecodeCallback) { this.onDecodeCallback(this, elapsedTime); } return true; }; MP2.prototype.getCurrentTime = function() { var enqueuedTime = this.destination ? this.destination.enqueuedTime : 0; return this.decodedTime - enqueuedTime; }; MP2.prototype.decodeFrame = function(left, right) { // Check for valid header: syncword OK, MPEG-Audio Layer 2 var sync = this.bits.read(11), version = this.bits.read(2), layer = this.bits.read(2), hasCRC = !this.bits.read(1); if ( sync !== MP2.FRAME_SYNC || version !== MP2.VERSION.MPEG_1 || layer !== MP2.LAYER.II ) { return 0; // Invalid header or unsupported version } var bitrateIndex = this.bits.read(4) - 1; if (bitrateIndex > 13) { return 0; // Invalid bit rate or 'free format' } var sampleRateIndex = this.bits.read(2); var sampleRate = MP2.SAMPLE_RATE[sampleRateIndex]; if (sampleRateIndex === 3) { return 0; // Invalid sample rate } if (version === MP2.VERSION.MPEG_2) { sampleRateIndex += 4; bitrateIndex += 14; } var padding = this.bits.read(1), privat = this.bits.read(1), mode = this.bits.read(2); // Parse the mode_extension, set up the stereo bound var bound = 0; if (mode === MP2.MODE.JOINT_STEREO) { bound = (this.bits.read(2) + 1) << 2; } else { this.bits.skip(2); bound = (mode === MP2.MODE.MONO) ? 0 : 32; } // Discard the last 4 bits of the header and the CRC value, if present this.bits.skip(4); if (hasCRC) { this.bits.skip(16); } // Compute the frame size var bitrate = MP2.BIT_RATE[bitrateIndex], sampleRate = MP2.SAMPLE_RATE[sampleRateIndex], frameSize = ((144000 * bitrate / sampleRate) + padding)|0; // Prepare the quantizer table lookups var tab3 = 0; var sblimit = 0; if (version === MP2.VERSION.MPEG_2) { // MPEG-2 (LSR) tab3 = 2; sblimit = 30; } else { // MPEG-1 var tab1 = (mode === MP2.MODE.MONO) ? 0 : 1; var tab2 = MP2.QUANT_LUT_STEP_1[tab1][bitrateIndex]; tab3 = MP2.QUANT_LUT_STEP_2[tab2][sampleRateIndex]; sblimit = tab3 & 63; tab3 >>= 6; } if (bound > sblimit) { bound = sblimit; } // Read the allocation information for (var sb = 0; sb < bound; sb++) { this.allocation[0][sb] = this.readAllocation(sb, tab3); this.allocation[1][sb] = this.readAllocation(sb, tab3); } for (var sb = bound; sb < sblimit; sb++) { this.allocation[0][sb] = this.allocation[1][sb] = this.readAllocation(sb, tab3); } // Read scale factor selector information var channels = (mode === MP2.MODE.MONO) ? 1 : 2; for (var sb = 0; sb < sblimit; sb++) { for (ch = 0; ch < channels; ch++) { if (this.allocation[ch][sb]) { this.scaleFactorInfo[ch][sb] = this.bits.read(2); } } if (mode === MP2.MODE.MONO) { this.scaleFactorInfo[1][sb] = this.scaleFactorInfo[0][sb]; } } // Read scale factors for (var sb = 0; sb < sblimit; sb++) { for (var ch = 0; ch < channels; ch++) { if (this.allocation[ch][sb]) { var sf = this.scaleFactor[ch][sb]; switch (this.scaleFactorInfo[ch][sb]) { case 0: sf[0] = this.bits.read(6); sf[1] = this.bits.read(6); sf[2] = this.bits.read(6); break; case 1: sf[0] = sf[1] = this.bits.read(6); sf[2] = this.bits.read(6); break; case 2: sf[0] = sf[1] = sf[2] = this.bits.read(6); break; case 3: sf[0] = this.bits.read(6); sf[1] = sf[2] = this.bits.read(6); break; } } } if (mode === MP2.MODE.MONO) { this.scaleFactor[1][sb][0] = this.scaleFactor[0][sb][0]; this.scaleFactor[1][sb][1] = this.scaleFactor[0][sb][1]; this.scaleFactor[1][sb][2] = this.scaleFactor[0][sb][2]; } } // Coefficient input and reconstruction var outPos = 0; for (var part = 0; part < 3; part++) { for (var granule = 0; granule < 4; granule++) { // Read the samples for (var sb = 0; sb < bound; sb++) { this.readSamples(0, sb, part); this.readSamples(1, sb, part); } for (var sb = bound; sb < sblimit; sb++) { this.readSamples(0, sb, part); this.sample[1][sb][0] = this.sample[0][sb][0]; this.sample[1][sb][1] = this.sample[0][sb][1]; this.sample[1][sb][2] = this.sample[0][sb][2]; } for (var sb = sblimit; sb < 32; sb++) { this.sample[0][sb][0] = 0; this.sample[0][sb][1] = 0; this.sample[0][sb][2] = 0; this.sample[1][sb][0] = 0; this.sample[1][sb][1] = 0; this.sample[1][sb][2] = 0; } // Synthesis loop for (var p = 0; p < 3; p++) { // Shifting step this.VPos = (this.VPos - 64) & 1023; for (var ch = 0; ch < 2; ch++) { MP2.MatrixTransform(this.sample[ch], p, this.V, this.VPos); // Build U, windowing, calculate output JSMpeg.Fill(this.U, 0); var dIndex = 512 - (this.VPos >> 1); var vIndex = (this.VPos % 128) >> 1; while (vIndex < 1024) { for (var i = 0; i < 32; ++i) { this.U[i] += this.D[dIndex++] * this.V[vIndex++]; } vIndex += 128-32; dIndex += 64-32; } vIndex = (128-32 + 1024) - vIndex; dIndex -= (512 - 32); while (vIndex < 1024) { for (var i = 0; i < 32; ++i) { this.U[i] += this.D[dIndex++] * this.V[vIndex++]; } vIndex += 128-32; dIndex += 64-32; } // Output samples var outChannel = ch === 0 ? left : right; for (var j = 0; j < 32; j++) { outChannel[outPos + j] = this.U[j] / 2147418112; } } // End of synthesis channel loop outPos += 32; } // End of synthesis sub-block loop } // Decoding of the granule finished } this.sampleRate = sampleRate; return frameSize; }; MP2.prototype.readAllocation = function(sb, tab3) { var tab4 = MP2.QUANT_LUT_STEP_3[tab3][sb]; var qtab = MP2.QUANT_LUT_STEP4[tab4 & 15][this.bits.read(tab4 >> 4)]; return qtab ? (MP2.QUANT_TAB[qtab - 1]) : 0; }; MP2.prototype.readSamples = function(ch, sb, part) { var q = this.allocation[ch][sb], sf = this.scaleFactor[ch][sb][part], sample = this.sample[ch][sb], val = 0; if (!q) { // No bits allocated for this subband sample[0] = sample[1] = sample[2] = 0; return; } // Resolve scalefactor if (sf === 63) { sf = 0; } else { var shift = (sf / 3)|0; sf = (MP2.SCALEFACTOR_BASE[sf % 3] + ((1 << shift) >> 1)) >> shift; } // Decode samples var adj = q.levels; if (q.group) { // Decode grouped samples val = this.bits.read(q.bits); sample[0] = val % adj; val = (val / adj)|0; sample[1] = val % adj; sample[2] = (val / adj)|0; } else { // Decode direct samples sample[0] = this.bits.read(q.bits); sample[1] = this.bits.read(q.bits); sample[2] = this.bits.read(q.bits); } // Postmultiply samples var scale = (65536 / (adj + 1))|0; adj = ((adj + 1) >> 1) - 1; val = (adj - sample[0]) * scale; sample[0] = (val * (sf >> 12) + ((val * (sf & 4095) + 2048) >> 12)) >> 12; val = (adj - sample[1]) * scale; sample[1] = (val * (sf >> 12) + ((val * (sf & 4095) + 2048) >> 12)) >> 12; val = (adj - sample[2]) * scale; sample[2] = (val * (sf >> 12) + ((val * (sf & 4095) + 2048) >> 12)) >> 12; }; MP2.MatrixTransform = function(s, ss, d, dp) { var t01, t02, t03, t04, t05, t06, t07, t08, t09, t10, t11, t12, t13, t14, t15, t16, t17, t18, t19, t20, t21, t22, t23, t24, t25, t26, t27, t28, t29, t30, t31, t32, t33; t01 = s[ 0][ss] + s[31][ss]; t02 = (s[ 0][ss] - s[31][ss]) * 0.500602998235; t03 = s[ 1][ss] + s[30][ss]; t04 = (s[ 1][ss] - s[30][ss]) * 0.505470959898; t05 = s[ 2][ss] + s[29][ss]; t06 = (s[ 2][ss] - s[29][ss]) * 0.515447309923; t07 = s[ 3][ss] + s[28][ss]; t08 = (s[ 3][ss] - s[28][ss]) * 0.53104259109; t09 = s[ 4][ss] + s[27][ss]; t10 = (s[ 4][ss] - s[27][ss]) * 0.553103896034; t11 = s[ 5][ss] + s[26][ss]; t12 = (s[ 5][ss] - s[26][ss]) * 0.582934968206; t13 = s[ 6][ss] + s[25][ss]; t14 = (s[ 6][ss] - s[25][ss]) * 0.622504123036; t15 = s[ 7][ss] + s[24][ss]; t16 = (s[ 7][ss] - s[24][ss]) * 0.674808341455; t17 = s[ 8][ss] + s[23][ss]; t18 = (s[ 8][ss] - s[23][ss]) * 0.744536271002; t19 = s[ 9][ss] + s[22][ss]; t20 = (s[ 9][ss] - s[22][ss]) * 0.839349645416; t21 = s[10][ss] + s[21][ss]; t22 = (s[10][ss] - s[21][ss]) * 0.972568237862; t23 = s[11][ss] + s[20][ss]; t24 = (s[11][ss] - s[20][ss]) * 1.16943993343; t25 = s[12][ss] + s[19][ss]; t26 = (s[12][ss] - s[19][ss]) * 1.48416461631; t27 = s[13][ss] + s[18][ss]; t28 = (s[13][ss] - s[18][ss]) * 2.05778100995; t29 = s[14][ss] + s[17][ss]; t30 = (s[14][ss] - s[17][ss]) * 3.40760841847; t31 = s[15][ss] + s[16][ss]; t32 = (s[15][ss] - s[16][ss]) * 10.1900081235; t33 = t01 + t31; t31 = (t01 - t31) * 0.502419286188; t01 = t03 + t29; t29 = (t03 - t29) * 0.52249861494; t03 = t05 + t27; t27 = (t05 - t27) * 0.566944034816; t05 = t07 + t25; t25 = (t07 - t25) * 0.64682178336; t07 = t09 + t23; t23 = (t09 - t23) * 0.788154623451; t09 = t11 + t21; t21 = (t11 - t21) * 1.06067768599; t11 = t13 + t19; t19 = (t13 - t19) * 1.72244709824; t13 = t15 + t17; t17 = (t15 - t17) * 5.10114861869; t15 = t33 + t13; t13 = (t33 - t13) * 0.509795579104; t33 = t01 + t11; t01 = (t01 - t11) * 0.601344886935; t11 = t03 + t09; t09 = (t03 - t09) * 0.899976223136; t03 = t05 + t07; t07 = (t05 - t07) * 2.56291544774; t05 = t15 + t03; t15 = (t15 - t03) * 0.541196100146; t03 = t33 + t11; t11 = (t33 - t11) * 1.30656296488; t33 = t05 + t03; t05 = (t05 - t03) * 0.707106781187; t03 = t15 + t11; t15 = (t15 - t11) * 0.707106781187; t03 += t15; t11 = t13 + t07; t13 = (t13 - t07) * 0.541196100146; t07 = t01 + t09; t09 = (t01 - t09) * 1.30656296488; t01 = t11 + t07; t07 = (t11 - t07) * 0.707106781187; t11 = t13 + t09; t13 = (t13 - t09) * 0.707106781187; t11 += t13; t01 += t11; t11 += t07; t07 += t13; t09 = t31 + t17; t31 = (t31 - t17) * 0.509795579104; t17 = t29 + t19; t29 = (t29 - t19) * 0.601344886935; t19 = t27 + t21; t21 = (t27 - t21) * 0.899976223136; t27 = t25 + t23; t23 = (t25 - t23) * 2.56291544774; t25 = t09 + t27; t09 = (t09 - t27) * 0.541196100146; t27 = t17 + t19; t19 = (t17 - t19) * 1.30656296488; t17 = t25 + t27; t27 = (t25 - t27) * 0.707106781187; t25 = t09 + t19; t19 = (t09 - t19) * 0.707106781187; t25 += t19; t09 = t31 + t23; t31 = (t31 - t23) * 0.541196100146; t23 = t29 + t21; t21 = (t29 - t21) * 1.30656296488; t29 = t09 + t23; t23 = (t09 - t23) * 0.707106781187; t09 = t31 + t21; t31 = (t31 - t21) * 0.707106781187; t09 += t31; t29 += t09; t09 += t23; t23 += t31; t17 += t29; t29 += t25; t25 += t09; t09 += t27; t27 += t23; t23 += t19; t19 += t31; t21 = t02 + t32; t02 = (t02 - t32) * 0.502419286188; t32 = t04 + t30; t04 = (t04 - t30) * 0.52249861494; t30 = t06 + t28; t28 = (t06 - t28) * 0.566944034816; t06 = t08 + t26; t08 = (t08 - t26) * 0.64682178336; t26 = t10 + t24; t10 = (t10 - t24) * 0.788154623451; t24 = t12 + t22; t22 = (t12 - t22) * 1.06067768599; t12 = t14 + t20; t20 = (t14 - t20) * 1.72244709824; t14 = t16 + t18; t16 = (t16 - t18) * 5.10114861869; t18 = t21 + t14; t14 = (t21 - t14) * 0.509795579104; t21 = t32 + t12; t32 = (t32 - t12) * 0.601344886935; t12 = t30 + t24; t24 = (t30 - t24) * 0.899976223136; t30 = t06 + t26; t26 = (t06 - t26) * 2.56291544774; t06 = t18 + t30; t18 = (t18 - t30) * 0.541196100146; t30 = t21 + t12; t12 = (t21 - t12) * 1.30656296488; t21 = t06 + t30; t30 = (t06 - t30) * 0.707106781187; t06 = t18 + t12; t12 = (t18 - t12) * 0.707106781187; t06 += t12; t18 = t14 + t26; t26 = (t14 - t26) * 0.541196100146; t14 = t32 + t24; t24 = (t32 - t24) * 1.30656296488; t32 = t18 + t14; t14 = (t18 - t14) * 0.707106781187; t18 = t26 + t24; t24 = (t26 - t24) * 0.707106781187; t18 += t24; t32 += t18; t18 += t14; t26 = t14 + t24; t14 = t02 + t16; t02 = (t02 - t16) * 0.509795579104; t16 = t04 + t20; t04 = (t04 - t20) * 0.601344886935; t20 = t28 + t22; t22 = (t28 - t22) * 0.899976223136; t28 = t08 + t10; t10 = (t08 - t10) * 2.56291544774; t08 = t14 + t28; t14 = (t14 - t28) * 0.541196100146; t28 = t16 + t20; t20 = (t16 - t20) * 1.30656296488; t16 = t08 + t28; t28 = (t08 - t28) * 0.707106781187; t08 = t14 + t20; t20 = (t14 - t20) * 0.707106781187; t08 += t20; t14 = t02 + t10; t02 = (t02 - t10) * 0.541196100146; t10 = t04 + t22; t22 = (t04 - t22) * 1.30656296488; t04 = t14 + t10; t10 = (t14 - t10) * 0.707106781187; t14 = t02 + t22; t02 = (t02 - t22) * 0.707106781187; t14 += t02; t04 += t14; t14 += t10; t10 += t02; t16 += t04; t04 += t08; t08 += t14; t14 += t28; t28 += t10; t10 += t20; t20 += t02; t21 += t16; t16 += t32; t32 += t04; t04 += t06; t06 += t08; t08 += t18; t18 += t14; t14 += t30; t30 += t28; t28 += t26; t26 += t10; t10 += t12; t12 += t20; t20 += t24; t24 += t02; d[dp + 48] = -t33; d[dp + 49] = d[dp + 47] = -t21; d[dp + 50] = d[dp + 46] = -t17; d[dp + 51] = d[dp + 45] = -t16; d[dp + 52] = d[dp + 44] = -t01; d[dp + 53] = d[dp + 43] = -t32; d[dp + 54] = d[dp + 42] = -t29; d[dp + 55] = d[dp + 41] = -t04; d[dp + 56] = d[dp + 40] = -t03; d[dp + 57] = d[dp + 39] = -t06; d[dp + 58] = d[dp + 38] = -t25; d[dp + 59] = d[dp + 37] = -t08; d[dp + 60] = d[dp + 36] = -t11; d[dp + 61] = d[dp + 35] = -t18; d[dp + 62] = d[dp + 34] = -t09; d[dp + 63] = d[dp + 33] = -t14; d[dp + 32] = -t05; d[dp + 0] = t05; d[dp + 31] = -t30; d[dp + 1] = t30; d[dp + 30] = -t27; d[dp + 2] = t27; d[dp + 29] = -t28; d[dp + 3] = t28; d[dp + 28] = -t07; d[dp + 4] = t07; d[dp + 27] = -t26; d[dp + 5] = t26; d[dp + 26] = -t23; d[dp + 6] = t23; d[dp + 25] = -t10; d[dp + 7] = t10; d[dp + 24] = -t15; d[dp + 8] = t15; d[dp + 23] = -t12; d[dp + 9] = t12; d[dp + 22] = -t19; d[dp + 10] = t19; d[dp + 21] = -t20; d[dp + 11] = t20; d[dp + 20] = -t13; d[dp + 12] = t13; d[dp + 19] = -t24; d[dp + 13] = t24; d[dp + 18] = -t31; d[dp + 14] = t31; d[dp + 17] = -t02; d[dp + 15] = t02; d[dp + 16] = 0.0; }; MP2.FRAME_SYNC = 0x7ff; MP2.VERSION = { MPEG_2_5: 0x0, MPEG_2: 0x2, MPEG_1: 0x3 }; MP2.LAYER = { III: 0x1, II: 0x2, I: 0x3 }; MP2.MODE = { STEREO: 0x0, JOINT_STEREO: 0x1, DUAL_CHANNEL: 0x2, MONO: 0x3 }; MP2.SAMPLE_RATE = new Uint16Array([ 44100, 48000, 32000, 0, // MPEG-1 22050, 24000, 16000, 0 // MPEG-2 ]); MP2.BIT_RATE = new Uint16Array([ 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, // MPEG-1 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 // MPEG-2 ]); MP2.SCALEFACTOR_BASE = new Uint32Array([ 0x02000000, 0x01965FEA, 0x01428A30 ]); MP2.SYNTHESIS_WINDOW = new Float32Array([ 0.0, -0.5, -0.5, -0.5, -0.5, -0.5, -0.5, -1.0, -1.0, -1.0, -1.0, -1.5, -1.5, -2.0, -2.0, -2.5, -2.5, -3.0, -3.5, -3.5, -4.0, -4.5, -5.0, -5.5, -6.5, -7.0, -8.0, -8.5, -9.5, -10.5, -12.0, -13.0, -14.5, -15.5, -17.5, -19.0, -20.5, -22.5, -24.5, -26.5, -29.0, -31.5, -34.0, -36.5, -39.5, -42.5, -45.5, -48.5, -52.0, -55.5, -58.5, -62.5, -66.0, -69.5, -73.5, -77.0, -80.5, -84.5, -88.0, -91.5, -95.0, -98.0, -101.0, -104.0, 106.5, 109.0, 111.0, 112.5, 113.5, 114.0, 114.0, 113.5, 112.0, 110.5, 107.5, 104.0, 100.0, 94.5, 88.5, 81.5, 73.0, 63.5, 53.0, 41.5, 28.5, 14.5, -1.0, -18.0, -36.0, -55.5, -76.5, -98.5, -122.0, -147.0, -173.5, -200.5, -229.5, -259.5, -290.5, -322.5, -355.5, -389.5, -424.0, -459.5, -495.5, -532.0, -568.5, -605.0, -641.5, -678.0, -714.0, -749.0, -783.5, -817.0, -849.0, -879.5, -908.5, -935.0, -959.5, -981.0, -1000.5, -1016.0, -1028.5, -1037.5, -1042.5, -1043.5, -1040.0, -1031.5, 1018.5, 1000.0, 976.0, 946.5, 911.0, 869.5, 822.0, 767.5, 707.0, 640.0, 565.5, 485.0, 397.0, 302.5, 201.0, 92.5, -22.5, -144.0, -272.5, -407.0, -547.5, -694.0, -846.0, -1003.0, -1165.0, -1331.5, -1502.0, -1675.5, -1852.5, -2031.5, -2212.5, -2394.0, -2576.5, -2758.5, -2939.5, -3118.5, -3294.5, -3467.5, -3635.5, -3798.5, -3955.0, -4104.5, -4245.5, -4377.5, -4499.0, -4609.5, -4708.0, -4792.5, -4863.5, -4919.0, -4958.0, -4979.5, -4983.0, -4967.5, -4931.5, -4875.0, -4796.0, -4694.5, -4569.5, -4420.0, -4246.0, -4046.0, -3820.0, -3567.0, 3287.0, 2979.5, 2644.0, 2280.5, 1888.0, 1467.5, 1018.5, 541.0, 35.0, -499.0, -1061.0, -1650.0, -2266.5, -2909.0, -3577.0, -4270.0, -4987.5, -5727.5, -6490.0, -7274.0, -8077.5, -8899.5, -9739.0, -10594.5, -11464.5, -12347.0, -13241.0, -14144.5, -15056.0, -15973.5, -16895.5, -17820.0, -18744.5, -19668.0, -20588.0, -21503.0, -22410.5, -23308.5, -24195.0, -25068.5, -25926.5, -26767.0, -27589.0, -28389.0, -29166.5, -29919.0, -30644.5, -31342.0, -32009.5, -32645.0, -33247.0, -33814.5, -34346.0, -34839.5, -35295.0, -35710.0, -36084.5, -36417.5, -36707.5, -36954.0, -37156.5, -37315.0, -37428.0, -37496.0, 37519.0, 37496.0, 37428.0, 37315.0, 37156.5, 36954.0, 36707.5, 36417.5, 36084.5, 35710.0, 35295.0, 34839.5, 34346.0, 33814.5, 33247.0, 32645.0, 32009.5, 31342.0, 30644.5, 29919.0, 29166.5, 28389.0, 27589.0, 26767.0, 25926.5, 25068.5, 24195.0, 23308.5, 22410.5, 21503.0, 20588.0, 19668.0, 18744.5, 17820.0, 16895.5, 15973.5, 15056.0, 14144.5, 13241.0, 12347.0, 11464.5, 10594.5, 9739.0, 8899.5, 8077.5, 7274.0, 6490.0, 5727.5, 4987.5, 4270.0, 3577.0, 2909.0, 2266.5, 1650.0, 1061.0, 499.0, -35.0, -541.0, -1018.5, -1467.5, -1888.0, -2280.5, -2644.0, -2979.5, 3287.0, 3567.0, 3820.0, 4046.0, 4246.0, 4420.0, 4569.5, 4694.5, 4796.0, 4875.0, 4931.5, 4967.5, 4983.0, 4979.5, 4958.0, 4919.0, 4863.5, 4792.5, 4708.0, 4609.5, 4499.0, 4377.5, 4245.5, 4104.5, 3955.0, 3798.5, 3635.5, 3467.5, 3294.5, 3118.5, 2939.5, 2758.5, 2576.5, 2394.0, 2212.5, 2031.5, 1852.5, 1675.5, 1502.0, 1331.5, 1165.0, 1003.0, 846.0, 694.0, 547.5, 407.0, 272.5, 144.0, 22.5, -92.5, -201.0, -302.5, -397.0, -485.0, -565.5, -640.0, -707.0, -767.5, -822.0, -869.5, -911.0, -946.5, -976.0, -1000.0, 1018.5, 1031.5, 1040.0, 1043.5, 1042.5, 1037.5, 1028.5, 1016.0, 1000.5, 981.0, 959.5, 935.0, 908.5, 879.5, 849.0, 817.0, 783.5, 749.0, 714.0, 678.0, 641.5, 605.0, 568.5, 532.0, 495.5, 459.5, 424.0, 389.5, 355.5, 322.5, 290.5, 259.5, 229.5, 200.5, 173.5, 147.0, 122.0, 98.5, 76.5, 55.5, 36.0, 18.0, 1.0, -14.5, -28.5, -41.5, -53.0, -63.5, -73.0, -81.5, -88.5, -94.5, -100.0, -104.0, -107.5, -110.5, -112.0, -113.5, -114.0, -114.0, -113.5, -112.5, -111.0, -109.0, 106.5, 104.0, 101.0, 98.0, 95.0, 91.5, 88.0, 84.5, 80.5, 77.0, 73.5, 69.5, 66.0, 62.5, 58.5, 55.5, 52.0, 48.5, 45.5, 42.5, 39.5, 36.5, 34.0, 31.5, 29.0, 26.5, 24.5, 22.5, 20.5, 19.0, 17.5, 15.5, 14.5, 13.0, 12.0, 10.5, 9.5, 8.5, 8.0, 7.0, 6.5, 5.5, 5.0, 4.5, 4.0, 3.5, 3.5, 3.0, 2.5, 2.5, 2.0, 2.0, 1.5, 1.5, 1.0, 1.0, 1.0, 1.0, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5 ]); // Quantizer lookup, step 1: bitrate classes MP2.QUANT_LUT_STEP_1 = [ // 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 <- bitrate / chan [ 0, 0, 0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 2] // stereo ]; // Quantizer lookup, step 2: bitrate class, sample rate -> B2 table idx, sblimit MP2.QUANT_TAB = { A: (27 | 64), // Table 3-B.2a: high-rate, sblimit = 27 B: (30 | 64), // Table 3-B.2b: high-rate, sblimit = 30 C: 8, // Table 3-B.2c: low-rate, sblimit = 8 D: 12 // Table 3-B.2d: low-rate, sblimit = 12 }; MP2.QUANT_LUT_STEP_2 = [ // 44.1 kHz, 48 kHz, 32 kHz [MP2.QUANT_TAB.C, MP2.QUANT_TAB.C, MP2.QUANT_TAB.D], // 32 - 48 kbit/sec/ch [MP2.QUANT_TAB.A, MP2.QUANT_TAB.A, MP2.QUANT_TAB.A], // 56 - 80 kbit/sec/ch [MP2.QUANT_TAB.B, MP2.QUANT_TAB.A, MP2.QUANT_TAB.B] // 96+ kbit/sec/ch ]; // Quantizer lookup, step 3: B2 table, subband -> nbal, row index // (upper 4 bits: nbal, lower 4 bits: row index) MP2.QUANT_LUT_STEP_3 = [ // Low-rate table (3-B.2c and 3-B.2d) [ 0x44,0x44, 0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34 ], // High-rate table (3-B.2a and 3-B.2b) [ 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 ], // MPEG-2 LSR table (B.2 in ISO 13818-3) [ 0x45,0x45,0x45,0x45, 0x34,0x34,0x34,0x34,0x34,0x34,0x34, 0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24, 0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24 ] ]; // Quantizer lookup, step 4: table row, allocation[] value -> quant table index MP2.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], [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15] ]; MP2.QUANT_TAB = [ {levels: 3, group: 1, bits: 5}, // 1 {levels: 5, group: 1, bits: 7}, // 2 {levels: 7, group: 0, bits: 3}, // 3 {levels: 9, group: 1, bits: 10}, // 4 {levels: 15, group: 0, bits: 4}, // 5 {levels: 31, group: 0, bits: 5}, // 6 {levels: 63, group: 0, bits: 6}, // 7 {levels: 127, group: 0, bits: 7}, // 8 {levels: 255, group: 0, bits: 8}, // 9 {levels: 511, group: 0, bits: 9}, // 10 {levels: 1023, group: 0, bits: 10}, // 11 {levels: 2047, group: 0, bits: 11}, // 12 {levels: 4095, group: 0, bits: 12}, // 13 {levels: 8191, group: 0, bits: 13}, // 14 {levels: 16383, group: 0, bits: 14}, // 15 {levels: 32767, group: 0, bits: 15}, // 16 {levels: 65535, group: 0, bits: 16} // 17 ]; return MP2; })();