Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 1 | /* Copyright (c) 2009-2010 Xiph.Org Foundation |
| 2 | Written by Jean-Marc Valin */ |
| 3 | /* |
| 4 | Redistribution and use in source and binary forms, with or without |
| 5 | modification, are permitted provided that the following conditions |
| 6 | are met: |
| 7 | |
| 8 | - Redistributions of source code must retain the above copyright |
| 9 | notice, this list of conditions and the following disclaimer. |
| 10 | |
| 11 | - Redistributions in binary form must reproduce the above copyright |
| 12 | notice, this list of conditions and the following disclaimer in the |
| 13 | documentation and/or other materials provided with the distribution. |
| 14 | |
| 15 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 16 | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 17 | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 18 | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER |
| 19 | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| 20 | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| 21 | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| 22 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 23 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 24 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 25 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | */ |
| 27 | |
| 28 | #ifdef HAVE_CONFIG_H |
| 29 | #include "config.h" |
| 30 | #endif |
| 31 | |
| 32 | #include "celt_lpc.h" |
| 33 | #include "stack_alloc.h" |
| 34 | #include "mathops.h" |
| 35 | |
| 36 | void _celt_lpc( |
| 37 | opus_val16 *_lpc, /* out: [0...p-1] LPC coefficients */ |
| 38 | const opus_val32 *ac, /* in: [0...p] autocorrelation values */ |
| 39 | int p |
| 40 | ) |
| 41 | { |
| 42 | int i, j; |
| 43 | opus_val32 r; |
| 44 | opus_val32 error = ac[0]; |
| 45 | #ifdef FIXED_POINT |
| 46 | opus_val32 lpc[LPC_ORDER]; |
| 47 | #else |
| 48 | float *lpc = _lpc; |
| 49 | #endif |
| 50 | |
| 51 | for (i = 0; i < p; i++) |
| 52 | lpc[i] = 0; |
| 53 | if (ac[0] != 0) |
| 54 | { |
| 55 | for (i = 0; i < p; i++) { |
| 56 | /* Sum up this iteration's reflection coefficient */ |
| 57 | opus_val32 rr = 0; |
| 58 | for (j = 0; j < i; j++) |
| 59 | rr += MULT32_32_Q31(lpc[j],ac[i - j]); |
| 60 | rr += SHR32(ac[i + 1],3); |
| 61 | r = -frac_div32(SHL32(rr,3), error); |
| 62 | /* Update LPC coefficients and total error */ |
| 63 | lpc[i] = SHR32(r,3); |
| 64 | for (j = 0; j < (i+1)>>1; j++) |
| 65 | { |
| 66 | opus_val32 tmp1, tmp2; |
| 67 | tmp1 = lpc[j]; |
| 68 | tmp2 = lpc[i-1-j]; |
| 69 | lpc[j] = tmp1 + MULT32_32_Q31(r,tmp2); |
| 70 | lpc[i-1-j] = tmp2 + MULT32_32_Q31(r,tmp1); |
| 71 | } |
| 72 | |
| 73 | error = error - MULT32_32_Q31(MULT32_32_Q31(r,r),error); |
| 74 | /* Bail out once we get 30 dB gain */ |
| 75 | #ifdef FIXED_POINT |
| 76 | if (error<SHR32(ac[0],10)) |
| 77 | break; |
| 78 | #else |
| 79 | if (error<.001f*ac[0]) |
| 80 | break; |
| 81 | #endif |
| 82 | } |
| 83 | } |
| 84 | #ifdef FIXED_POINT |
| 85 | for (i=0;i<p;i++) |
| 86 | _lpc[i] = ROUND16(lpc[i],16); |
| 87 | #endif |
| 88 | } |
| 89 | |
| 90 | void celt_fir(const opus_val16 *x, |
| 91 | const opus_val16 *num, |
| 92 | opus_val16 *y, |
| 93 | int N, |
| 94 | int ord, |
| 95 | opus_val16 *mem) |
| 96 | { |
| 97 | int i,j; |
| 98 | |
| 99 | for (i=0;i<N;i++) |
| 100 | { |
| 101 | opus_val32 sum = SHL32(EXTEND32(x[i]), SIG_SHIFT); |
| 102 | for (j=0;j<ord;j++) |
| 103 | { |
| 104 | sum += MULT16_16(num[j],mem[j]); |
| 105 | } |
| 106 | for (j=ord-1;j>=1;j--) |
| 107 | { |
| 108 | mem[j]=mem[j-1]; |
| 109 | } |
| 110 | mem[0] = x[i]; |
| 111 | y[i] = ROUND16(sum, SIG_SHIFT); |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | void celt_iir(const opus_val32 *x, |
| 116 | const opus_val16 *den, |
| 117 | opus_val32 *y, |
| 118 | int N, |
| 119 | int ord, |
| 120 | opus_val16 *mem) |
| 121 | { |
| 122 | int i,j; |
| 123 | for (i=0;i<N;i++) |
| 124 | { |
| 125 | opus_val32 sum = x[i]; |
| 126 | for (j=0;j<ord;j++) |
| 127 | { |
| 128 | sum -= MULT16_16(den[j],mem[j]); |
| 129 | } |
| 130 | for (j=ord-1;j>=1;j--) |
| 131 | { |
| 132 | mem[j]=mem[j-1]; |
| 133 | } |
| 134 | mem[0] = ROUND16(sum,SIG_SHIFT); |
| 135 | y[i] = sum; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | void _celt_autocorr( |
| 140 | const opus_val16 *x, /* in: [0...n-1] samples x */ |
| 141 | opus_val32 *ac, /* out: [0...lag-1] ac values */ |
| 142 | const opus_val16 *window, |
| 143 | int overlap, |
| 144 | int lag, |
| 145 | int n |
| 146 | ) |
| 147 | { |
| 148 | opus_val32 d; |
| 149 | int i; |
| 150 | VARDECL(opus_val16, xx); |
| 151 | SAVE_STACK; |
| 152 | ALLOC(xx, n, opus_val16); |
| 153 | celt_assert(n>0); |
| 154 | celt_assert(overlap>=0); |
| 155 | for (i=0;i<n;i++) |
| 156 | xx[i] = x[i]; |
| 157 | for (i=0;i<overlap;i++) |
| 158 | { |
| 159 | xx[i] = MULT16_16_Q15(x[i],window[i]); |
| 160 | xx[n-i-1] = MULT16_16_Q15(x[n-i-1],window[i]); |
| 161 | } |
| 162 | #ifdef FIXED_POINT |
| 163 | { |
| 164 | opus_val32 ac0=0; |
| 165 | int shift; |
| 166 | for(i=0;i<n;i++) |
| 167 | ac0 += SHR32(MULT16_16(xx[i],xx[i]),9); |
| 168 | ac0 += 1+n; |
| 169 | |
| 170 | shift = celt_ilog2(ac0)-30+10; |
| 171 | shift = (shift+1)/2; |
| 172 | for(i=0;i<n;i++) |
| 173 | xx[i] = VSHR32(xx[i], shift); |
| 174 | } |
| 175 | #endif |
| 176 | while (lag>=0) |
| 177 | { |
| 178 | for (i = lag, d = 0; i < n; i++) |
| 179 | d += xx[i] * xx[i-lag]; |
| 180 | ac[lag] = d; |
| 181 | /*printf ("%f ", ac[lag]);*/ |
| 182 | lag--; |
| 183 | } |
| 184 | /*printf ("\n");*/ |
| 185 | ac[0] += 10; |
| 186 | |
| 187 | RESTORE_STACK; |
| 188 | } |