163 lines
6.5 KiB
C#
163 lines
6.5 KiB
C#
/* Copyright (c) 2007-2008 CSIRO
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Copyright (c) 2007-2011 Xiph.Org Foundation
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Originally written by Jean-Marc Valin, Gregory Maxwell, Koen Vos,
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Timothy B. Terriberry, and the Opus open-source contributors
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Ported to C# by Logan Stromberg
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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- Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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- Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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- Neither the name of Internet Society, IETF or IETF Trust, nor the
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names of specific contributors, may be used to endorse or promote
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products derived from this software without specific prior written
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permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
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OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#if UNSAFE
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namespace Concentus.Celt
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{
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using Concentus.Celt.Enums;
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using Concentus.Celt.Structs;
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using Concentus.Common;
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using Concentus.Common.CPlusPlus;
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using System.Diagnostics;
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internal static class CeltLPC
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{
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internal static void celt_lpc(
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int[] _lpc, /* out: [0...p-1] LPC coefficients */
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int[] ac, /* in: [0...p] autocorrelation values */
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int p)
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{
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int i, j;
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int r;
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int error = ac[0];
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int[] lpc = new int[p];
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//Arrays.MemSetInt(lpc, 0, p); strictly, this is not necessary since the runtime zeroes memory for us
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if (ac[0] != 0)
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{
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for (i = 0; i < p; i++)
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{
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/* Sum up this iteration's reflection coefficient */
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int rr = 0;
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for (j = 0; j < i; j++)
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rr += Inlines.MULT32_32_Q31(lpc[j], ac[i - j]);
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rr += Inlines.SHR32(ac[i + 1], 3);
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r = 0 - Inlines.frac_div32(Inlines.SHL32(rr, 3), error);
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/* Update LPC coefficients and total error */
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lpc[i] = Inlines.SHR32(r, 3);
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for (j = 0; j < (i + 1) >> 1; j++)
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{
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int tmp1, tmp2;
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tmp1 = lpc[j];
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tmp2 = lpc[i - 1 - j];
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lpc[j] = tmp1 + Inlines.MULT32_32_Q31(r, tmp2);
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lpc[i - 1 - j] = tmp2 + Inlines.MULT32_32_Q31(r, tmp1);
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}
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error = error - Inlines.MULT32_32_Q31(Inlines.MULT32_32_Q31(r, r), error);
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/* Bail out once we get 30 dB gain */
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if (error < Inlines.SHR32(ac[0], 10))
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{
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break;
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}
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}
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}
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for (i = 0; i < p; i++)
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{
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_lpc[i] = Inlines.ROUND16((lpc[i]), 16);
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}
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}
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internal static unsafe void celt_iir(
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int[] _x,
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int _x_ptr,
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int[] den,
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int[] _y,
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int _y_ptr,
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int N,
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int ord,
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int[] mem)
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{
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int i, j;
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int[] rden = new int[ord];
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int[] y = new int[N + ord];
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Inlines.OpusAssert((ord & 3) == 0);
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fixed (int* prden = rden, py_base = y)
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{
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for (i = 0; i < ord; i++)
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rden[i] = den[ord - i - 1];
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for (i = 0; i < ord; i++)
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y[i] = (0 - mem[ord - i - 1]);
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for (; i < N + ord; i++)
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y[i] = 0;
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for (i = 0; i < N - 3; i += 4)
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{
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int* py = py_base + i;
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/* Unroll by 4 as if it were an FIR filter */
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int sum0 = _x[_x_ptr + i];
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int sum1 = _x[_x_ptr + i + 1];
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int sum2 = _x[_x_ptr + i + 2];
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int sum3 = _x[_x_ptr + i + 3];
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Kernels.xcorr_kernel(prden, py, ref sum0, ref sum1, ref sum2, ref sum3, ord);
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/* Patch up the result to compensate for the fact that this is an IIR */
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y[i + ord] = (0 - Inlines.ROUND16((sum0), CeltConstants.SIG_SHIFT));
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_y[_y_ptr + i] = sum0;
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sum1 = Inlines.MAC16_16(sum1, y[i + ord], den[0]);
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y[i + ord + 1] = (0 - Inlines.ROUND16((sum1), CeltConstants.SIG_SHIFT));
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_y[_y_ptr + i + 1] = sum1;
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sum2 = Inlines.MAC16_16(sum2, y[i + ord + 1], den[0]);
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sum2 = Inlines.MAC16_16(sum2, y[i + ord], den[1]);
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y[i + ord + 2] = (0 - Inlines.ROUND16((sum2), CeltConstants.SIG_SHIFT));
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_y[_y_ptr + i + 2] = sum2;
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sum3 = Inlines.MAC16_16(sum3, y[i + ord + 2], den[0]);
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sum3 = Inlines.MAC16_16(sum3, y[i + ord + 1], den[1]);
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sum3 = Inlines.MAC16_16(sum3, y[i + ord], den[2]);
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y[i + ord + 3] = (0 - Inlines.ROUND16((sum3), CeltConstants.SIG_SHIFT));
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_y[_y_ptr + i + 3] = sum3;
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}
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for (; i < N; i++)
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{
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int sum = _x[_x_ptr + i];
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for (j = 0; j < ord; j++)
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sum -= Inlines.MULT16_16(rden[j], y[i + j]);
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y[i + ord] = Inlines.ROUND16((sum), CeltConstants.SIG_SHIFT);
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_y[_y_ptr + i] = sum;
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}
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for (i = 0; i < ord; i++)
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mem[i] = (_y[_y_ptr + N - i - 1]);
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}
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}
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}
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}
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#endif |