/* * NLayer - A C# MPEG1/2/2.5 audio decoder * * Portions of this file are courtesy Fluendo, S.A. They are dual licensed as Ms-PL * and under the following license: * * Copyright <2005-2012> Fluendo S.A. * * Unless otherwise indicated, Source Code is licensed under MIT license. * See further explanation attached in License Statement (distributed in the file * LICENSE). * * Permission is hereby granted, free of charge, to any person obtaining a copy of * this software and associated documentation files (the "Software"), to deal in * the Software without restriction, including without limitation the rights to * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies * of the Software, and to permit persons to whom the Software is furnished to do * so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. * */ using System.Collections.Generic; namespace NLayer.Decoder { abstract class LayerDecoderBase { protected const int SBLIMIT = 32; const float INV_SQRT_2 = 7.071067811865474617150084668537e-01f; #region Tables static float[] DEWINDOW_TABLE = { 0.000000000f, -0.000015259f, -0.000015259f, -0.000015259f, -0.000015259f, -0.000015259f, -0.000015259f, -0.000030518f, -0.000030518f, -0.000030518f, -0.000030518f, -0.000045776f, -0.000045776f, -0.000061035f, -0.000061035f, -0.000076294f, -0.000076294f, -0.000091553f, -0.000106812f, -0.000106812f, -0.000122070f, -0.000137329f, -0.000152588f, -0.000167847f, -0.000198364f, -0.000213623f, -0.000244141f, -0.000259399f, -0.000289917f, -0.000320435f, -0.000366211f, -0.000396729f, -0.000442505f, -0.000473022f, -0.000534058f, -0.000579834f, -0.000625610f, -0.000686646f, -0.000747681f, -0.000808716f, -0.000885010f, -0.000961304f, -0.001037598f, -0.001113892f, -0.001205444f, -0.001296997f, -0.001388550f, -0.001480103f, -0.001586914f, -0.001693726f, -0.001785278f, -0.001907349f, -0.002014160f, -0.002120972f, -0.002243042f, -0.002349854f, -0.002456665f, -0.002578735f, -0.002685547f, -0.002792358f, -0.002899170f, -0.002990723f, -0.003082275f, -0.003173828f, 0.003250122f, 0.003326416f, 0.003387451f, 0.003433228f, 0.003463745f, 0.003479004f, 0.003479004f, 0.003463745f, 0.003417969f, 0.003372192f, 0.003280640f, 0.003173828f, 0.003051758f, 0.002883911f, 0.002700806f, 0.002487183f, 0.002227783f, 0.001937866f, 0.001617432f, 0.001266479f, 0.000869751f, 0.000442505f, -0.000030518f, -0.000549316f, -0.001098633f, -0.001693726f, -0.002334595f, -0.003005981f, -0.003723145f, -0.004486084f, -0.005294800f, -0.006118774f, -0.007003784f, -0.007919312f, -0.008865356f, -0.009841919f, -0.010848999f, -0.011886597f, -0.012939453f, -0.014022827f, -0.015121460f, -0.016235352f, -0.017349243f, -0.018463135f, -0.019577026f, -0.020690918f, -0.021789551f, -0.022857666f, -0.023910522f, -0.024932861f, -0.025909424f, -0.026840210f, -0.027725220f, -0.028533936f, -0.029281616f, -0.029937744f, -0.030532837f, -0.031005859f, -0.031387329f, -0.031661987f, -0.031814575f, -0.031845093f, -0.031738281f, -0.031478882f, 0.031082153f, 0.030517578f, 0.029785156f, 0.028884888f, 0.027801514f, 0.026535034f, 0.025085449f, 0.023422241f, 0.021575928f, 0.019531250f, 0.017257690f, 0.014801025f, 0.012115479f, 0.009231567f, 0.006134033f, 0.002822876f, -0.000686646f, -0.004394531f, -0.008316040f, -0.012420654f, -0.016708374f, -0.021179199f, -0.025817871f, -0.030609131f, -0.035552979f, -0.040634155f, -0.045837402f, -0.051132202f, -0.056533813f, -0.061996460f, -0.067520142f, -0.073059082f, -0.078628540f, -0.084182739f, -0.089706421f, -0.095169067f, -0.100540161f, -0.105819702f, -0.110946655f, -0.115921021f, -0.120697021f, -0.125259399f, -0.129562378f, -0.133590698f, -0.137298584f, -0.140670776f, -0.143676758f, -0.146255493f, -0.148422241f, -0.150115967f, -0.151306152f, -0.151962280f, -0.152069092f, -0.151596069f, -0.150497437f, -0.148773193f, -0.146362305f, -0.143264771f, -0.139450073f, -0.134887695f, -0.129577637f, -0.123474121f, -0.116577148f, -0.108856201f, 0.100311279f, 0.090927124f, 0.080688477f, 0.069595337f, 0.057617187f, 0.044784546f, 0.031082153f, 0.016510010f, 0.001068115f, -0.015228271f, -0.032379150f, -0.050354004f, -0.069168091f, -0.088775635f, -0.109161377f, -0.130310059f, -0.152206421f, -0.174789429f, -0.198059082f, -0.221984863f, -0.246505737f, -0.271591187f, -0.297210693f, -0.323318481f, -0.349868774f, -0.376800537f, -0.404083252f, -0.431655884f, -0.459472656f, -0.487472534f, -0.515609741f, -0.543823242f, -0.572036743f, -0.600219727f, -0.628295898f, -0.656219482f, -0.683914185f, -0.711318970f, -0.738372803f, -0.765029907f, -0.791213989f, -0.816864014f, -0.841949463f, -0.866363525f, -0.890090942f, -0.913055420f, -0.935195923f, -0.956481934f, -0.976852417f, -0.996246338f, -1.014617920f, -1.031936646f, -1.048156738f, -1.063217163f, -1.077117920f, -1.089782715f, -1.101211548f, -1.111373901f, -1.120223999f, -1.127746582f, -1.133926392f, -1.138763428f, -1.142211914f, -1.144287109f, 1.144989014f, 1.144287109f, 1.142211914f, 1.138763428f, 1.133926392f, 1.127746582f, 1.120223999f, 1.111373901f, 1.101211548f, 1.089782715f, 1.077117920f, 1.063217163f, 1.048156738f, 1.031936646f, 1.014617920f, 0.996246338f, 0.976852417f, 0.956481934f, 0.935195923f, 0.913055420f, 0.890090942f, 0.866363525f, 0.841949463f, 0.816864014f, 0.791213989f, 0.765029907f, 0.738372803f, 0.711318970f, 0.683914185f, 0.656219482f, 0.628295898f, 0.600219727f, 0.572036743f, 0.543823242f, 0.515609741f, 0.487472534f, 0.459472656f, 0.431655884f, 0.404083252f, 0.376800537f, 0.349868774f, 0.323318481f, 0.297210693f, 0.271591187f, 0.246505737f, 0.221984863f, 0.198059082f, 0.174789429f, 0.152206421f, 0.130310059f, 0.109161377f, 0.088775635f, 0.069168091f, 0.050354004f, 0.032379150f, 0.015228271f, -0.001068115f, -0.016510010f, -0.031082153f, -0.044784546f, -0.057617187f, -0.069595337f, -0.080688477f, -0.090927124f, 0.100311279f, 0.108856201f, 0.116577148f, 0.123474121f, 0.129577637f, 0.134887695f, 0.139450073f, 0.143264771f, 0.146362305f, 0.148773193f, 0.150497437f, 0.151596069f, 0.152069092f, 0.151962280f, 0.151306152f, 0.150115967f, 0.148422241f, 0.146255493f, 0.143676758f, 0.140670776f, 0.137298584f, 0.133590698f, 0.129562378f, 0.125259399f, 0.120697021f, 0.115921021f, 0.110946655f, 0.105819702f, 0.100540161f, 0.095169067f, 0.089706421f, 0.084182739f, 0.078628540f, 0.073059082f, 0.067520142f, 0.061996460f, 0.056533813f, 0.051132202f, 0.045837402f, 0.040634155f, 0.035552979f, 0.030609131f, 0.025817871f, 0.021179199f, 0.016708374f, 0.012420654f, 0.008316040f, 0.004394531f, 0.000686646f, -0.002822876f, -0.006134033f, -0.009231567f, -0.012115479f, -0.014801025f, -0.017257690f, -0.019531250f, -0.021575928f, -0.023422241f, -0.025085449f, -0.026535034f, -0.027801514f, -0.028884888f, -0.029785156f, -0.030517578f, 0.031082153f, 0.031478882f, 0.031738281f, 0.031845093f, 0.031814575f, 0.031661987f, 0.031387329f, 0.031005859f, 0.030532837f, 0.029937744f, 0.029281616f, 0.028533936f, 0.027725220f, 0.026840210f, 0.025909424f, 0.024932861f, 0.023910522f, 0.022857666f, 0.021789551f, 0.020690918f, 0.019577026f, 0.018463135f, 0.017349243f, 0.016235352f, 0.015121460f, 0.014022827f, 0.012939453f, 0.011886597f, 0.010848999f, 0.009841919f, 0.008865356f, 0.007919312f, 0.007003784f, 0.006118774f, 0.005294800f, 0.004486084f, 0.003723145f, 0.003005981f, 0.002334595f, 0.001693726f, 0.001098633f, 0.000549316f, 0.000030518f, -0.000442505f, -0.000869751f, -0.001266479f, -0.001617432f, -0.001937866f, -0.002227783f, -0.002487183f, -0.002700806f, -0.002883911f, -0.003051758f, -0.003173828f, -0.003280640f, -0.003372192f, -0.003417969f, -0.003463745f, -0.003479004f, -0.003479004f, -0.003463745f, -0.003433228f, -0.003387451f, -0.003326416f, 0.003250122f, 0.003173828f, 0.003082275f, 0.002990723f, 0.002899170f, 0.002792358f, 0.002685547f, 0.002578735f, 0.002456665f, 0.002349854f, 0.002243042f, 0.002120972f, 0.002014160f, 0.001907349f, 0.001785278f, 0.001693726f, 0.001586914f, 0.001480103f, 0.001388550f, 0.001296997f, 0.001205444f, 0.001113892f, 0.001037598f, 0.000961304f, 0.000885010f, 0.000808716f, 0.000747681f, 0.000686646f, 0.000625610f, 0.000579834f, 0.000534058f, 0.000473022f, 0.000442505f, 0.000396729f, 0.000366211f, 0.000320435f, 0.000289917f, 0.000259399f, 0.000244141f, 0.000213623f, 0.000198364f, 0.000167847f, 0.000152588f, 0.000137329f, 0.000122070f, 0.000106812f, 0.000106812f, 0.000091553f, 0.000076294f, 0.000076294f, 0.000061035f, 0.000061035f, 0.000045776f, 0.000045776f, 0.000030518f, 0.000030518f, 0.000030518f, 0.000030518f, 0.000015259f, 0.000015259f, 0.000015259f, 0.000015259f, 0.000015259f, 0.000015259f }; static float[] SYNTH_COS64_TABLE = { 5.0060299823519627260e-01f, 5.0241928618815567820e-01f, 5.0547095989754364798e-01f, 5.0979557910415917998e-01f, 5.1544730992262455249e-01f, 5.2249861493968885462e-01f, 5.3104259108978413284e-01f, 5.4119610014619701222e-01f, 5.5310389603444454210e-01f, 5.6694403481635768927e-01f, 5.8293496820613388554e-01f, 6.0134488693504528634e-01f, 6.2250412303566482475e-01f, 6.4682178335999007679e-01f, 6.7480834145500567800e-01f, 7.0710678118654746172e-01f, 7.4453627100229857749e-01f, 7.8815462345125020249e-01f, 8.3934964541552681272e-01f, 8.9997622313641556513e-01f, 9.7256823786196078263e-01f, 1.0606776859903470633e+00f, 1.1694399334328846596e+00f, 1.3065629648763763537e+00f, 1.4841646163141661852e+00f, 1.7224470982383341955e+00f, 2.0577810099534108446e+00f, 2.5629154477415054814e+00f, 3.4076084184687189804e+00f, 5.1011486186891552563e+00f, 1.0190008123548032870e+01f }; #endregion List _synBuf = new List(2); List _bufOffset = new List(2); float[] _eq; internal LayerDecoderBase() { StereoMode = StereoMode.Both; } abstract internal int DecodeFrame(IMpegFrame frame, float[] ch0, float[] ch1); internal void SetEQ(float[] eq) { if (eq == null || eq.Length == 32) { _eq = eq; } } internal StereoMode StereoMode { get; set; } virtual internal void ResetForSeek() { _synBuf.Clear(); _bufOffset.Clear(); } float[] ippuv = new float[512]; protected void InversePolyPhase(int channel, float[] data) { float[] synBuf; int k; GetBufAndOffset(channel, out synBuf, out k); if (_eq != null) { for (int i = 0; i < 32; i++) { data[i] *= _eq[i]; } } DCT32(data, synBuf, k); BuildUVec(ippuv, synBuf, k); DewindowOutput(ippuv, data); } void GetBufAndOffset(int channel, out float[] synBuf, out int k) { while (_synBuf.Count <= channel) { _synBuf.Add(new float[1024]); } while (_bufOffset.Count <= channel) { _bufOffset.Add(0); } synBuf = _synBuf[channel]; k = _bufOffset[channel]; k = (k - 32) & 511; _bufOffset[channel] = k; } float[] ei32 = new float[16], eo32 = new float[16], oi32 = new float[16], oo32 = new float[16]; void DCT32(float[] _in, float[] _out, int k) { int i; for (i = 0; i < 16; i++) { ei32[i] = _in[i] + _in[31 - i]; oi32[i] = (_in[i] - _in[31 - i]) * SYNTH_COS64_TABLE[2 * i]; } DCT16(ei32, eo32); DCT16(oi32, oo32); for (i = 0; i < 15; i++) { _out[2 * i + k] = eo32[i]; _out[2 * i + 1 + k] = oo32[i] + oo32[i + 1]; } _out[30 + k] = eo32[15]; _out[31 + k] = oo32[15]; } float[] ei16 = new float[8], eo16 = new float[8], oi16 = new float[8], oo16 = new float[8]; void DCT16(float[] _in, float[] _out) { float a, b; a = _in[0]; b = _in[15]; ei16[0] = a + b; oi16[0] = (a - b) * SYNTH_COS64_TABLE[1]; a = _in[1]; b = _in[14]; ei16[1] = a + b; oi16[1] = (a - b) * SYNTH_COS64_TABLE[5]; a = _in[2]; b = _in[13]; ei16[2] = a + b; oi16[2] = (a - b) * SYNTH_COS64_TABLE[9]; a = _in[3]; b = _in[12]; ei16[3] = a + b; oi16[3] = (a - b) * SYNTH_COS64_TABLE[13]; a = _in[4]; b = _in[11]; ei16[4] = a + b; oi16[4] = (a - b) * SYNTH_COS64_TABLE[17]; a = _in[5]; b = _in[10]; ei16[5] = a + b; oi16[5] = (a - b) * SYNTH_COS64_TABLE[21]; a = _in[6]; b = _in[9]; ei16[6] = a + b; oi16[6] = (a - b) * SYNTH_COS64_TABLE[25]; a = _in[7]; b = _in[8]; ei16[7] = a + b; oi16[7] = (a - b) * SYNTH_COS64_TABLE[29]; DCT8(ei16, eo16); DCT8(oi16, oo16); _out[0] = eo16[0]; _out[1] = oo16[0] + oo16[1]; _out[2] = eo16[1]; _out[3] = oo16[1] + oo16[2]; _out[4] = eo16[2]; _out[5] = oo16[2] + oo16[3]; _out[6] = eo16[3]; _out[7] = oo16[3] + oo16[4]; _out[8] = eo16[4]; _out[9] = oo16[4] + oo16[5]; _out[10] = eo16[5]; _out[11] = oo16[5] + oo16[6]; _out[12] = eo16[6]; _out[13] = oo16[6] + oo16[7]; _out[14] = eo16[7]; _out[15] = oo16[7]; } float[] ei8 = new float[4], tmp8 = new float[6], oi8 = new float[4], oo8 = new float[4]; void DCT8(float[] _in, float[] _out) { /* Even indices */ ei8[0] = _in[0] + _in[7]; ei8[1] = _in[3] + _in[4]; ei8[2] = _in[1] + _in[6]; ei8[3] = _in[2] + _in[5]; tmp8[0] = ei8[0] + ei8[1]; tmp8[1] = ei8[2] + ei8[3]; tmp8[2] = (ei8[0] - ei8[1]) * SYNTH_COS64_TABLE[7]; tmp8[3] = (ei8[2] - ei8[3]) * SYNTH_COS64_TABLE[23]; tmp8[4] = (float)((tmp8[2] - tmp8[3]) * INV_SQRT_2); _out[0] = tmp8[0] + tmp8[1]; _out[2] = tmp8[2] + tmp8[3] + tmp8[4]; _out[4] = (float)((tmp8[0] - tmp8[1]) * INV_SQRT_2); _out[6] = tmp8[4]; /* Odd indices */ oi8[0] = (_in[0] - _in[7]) * SYNTH_COS64_TABLE[3]; oi8[1] = (_in[1] - _in[6]) * SYNTH_COS64_TABLE[11]; oi8[2] = (_in[2] - _in[5]) * SYNTH_COS64_TABLE[19]; oi8[3] = (_in[3] - _in[4]) * SYNTH_COS64_TABLE[27]; tmp8[0] = oi8[0] + oi8[3]; tmp8[1] = oi8[1] + oi8[2]; tmp8[2] = (oi8[0] - oi8[3]) * SYNTH_COS64_TABLE[7]; tmp8[3] = (oi8[1] - oi8[2]) * SYNTH_COS64_TABLE[23]; tmp8[4] = tmp8[2] + tmp8[3]; tmp8[5] = (float)((tmp8[2] - tmp8[3]) * INV_SQRT_2); oo8[0] = tmp8[0] + tmp8[1]; oo8[1] = tmp8[4] + tmp8[5]; oo8[2] = (float)((tmp8[0] - tmp8[1]) * INV_SQRT_2); oo8[3] = tmp8[5]; _out[1] = oo8[0] + oo8[1]; _out[3] = oo8[1] + oo8[2]; _out[5] = oo8[2] + oo8[3]; _out[7] = oo8[3]; } void BuildUVec(float[] u_vec, float[] cur_synbuf, int k) { int i, j, uvp = 0; for (j = 0; j < 8; j++) { for (i = 0; i < 16; i++) { /* Copy first 32 elements */ u_vec[uvp + i] = cur_synbuf[k + i + 16]; u_vec[uvp + i + 17] = -cur_synbuf[k + 31 - i]; } /* k wraps at the synthesis buffer boundary */ k = (k + 32) & 511; for (i = 0; i < 16; i++) { /* Copy next 32 elements */ u_vec[uvp + i + 32] = -cur_synbuf[k + 16 - i]; u_vec[uvp + i + 48] = -cur_synbuf[k + i]; } u_vec[uvp + 16] = 0; /* k wraps at the synthesis buffer boundary */ k = (k + 32) & 511; uvp += 64; } } void DewindowOutput(float[] u_vec, float[] samples) { for (int i = 0; i < 512; i++) { u_vec[i] *= DEWINDOW_TABLE[i]; } for (int i = 0; i < 32; i++) { float sum = u_vec[i]; sum += u_vec[i + (1 << 5)]; sum += u_vec[i + (2 << 5)]; sum += u_vec[i + (3 << 5)]; sum += u_vec[i + (4 << 5)]; sum += u_vec[i + (5 << 5)]; sum += u_vec[i + (6 << 5)]; sum += u_vec[i + (7 << 5)]; sum += u_vec[i + (8 << 5)]; sum += u_vec[i + (9 << 5)]; sum += u_vec[i + (10 << 5)]; sum += u_vec[i + (11 << 5)]; sum += u_vec[i + (12 << 5)]; sum += u_vec[i + (13 << 5)]; sum += u_vec[i + (14 << 5)]; sum += u_vec[i + (15 << 5)]; u_vec[i] = sum; } for (int i = 0; i < 32; i++) { samples[i] = u_vec[i]; } } } }