diff options
| author | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:55:35 +0100 |
|---|---|---|
| committer | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:55:35 +0100 |
| commit | 741fb4b9e135cfb161a749db88713229038577bb (patch) | |
| tree | 08bc9925659cbcac45162bacf31dc6336d4f60b4 /ffmpeg1/libavcodec/lpc.c | |
| parent | a2e1bf3495b7bfefdaedb8fc737e969ab06df079 (diff) | |
making act segmenter
Diffstat (limited to 'ffmpeg1/libavcodec/lpc.c')
| -rw-r--r-- | ffmpeg1/libavcodec/lpc.c | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/ffmpeg1/libavcodec/lpc.c b/ffmpeg1/libavcodec/lpc.c deleted file mode 100644 index 4149135..0000000 --- a/ffmpeg1/libavcodec/lpc.c +++ /dev/null @@ -1,287 +0,0 @@ -/* - * LPC utility code - * Copyright (c) 2006 Justin Ruggles <justin.ruggles@gmail.com> - * - * This file is part of FFmpeg. - * - * FFmpeg is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * FFmpeg is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -#include "libavutil/common.h" -#include "libavutil/lls.h" - -#define LPC_USE_DOUBLE -#include "lpc.h" -#include "libavutil/avassert.h" - - -/** - * Apply Welch window function to audio block - */ -static void lpc_apply_welch_window_c(const int32_t *data, int len, - double *w_data) -{ - int i, n2; - double w; - double c; - - /* The optimization in commit fa4ed8c does not support odd len. - * If someone wants odd len extend that change. */ - av_assert2(!(len & 1)); - - n2 = (len >> 1); - c = 2.0 / (len - 1.0); - - w_data+=n2; - data+=n2; - for(i=0; i<n2; i++) { - w = c - n2 + i; - w = 1.0 - (w * w); - w_data[-i-1] = data[-i-1] * w; - w_data[+i ] = data[+i ] * w; - } -} - -/** - * Calculate autocorrelation data from audio samples - * A Welch window function is applied before calculation. - */ -static void lpc_compute_autocorr_c(const double *data, int len, int lag, - double *autoc) -{ - int i, j; - - for(j=0; j<lag; j+=2){ - double sum0 = 1.0, sum1 = 1.0; - for(i=j; i<len; i++){ - sum0 += data[i] * data[i-j]; - sum1 += data[i] * data[i-j-1]; - } - autoc[j ] = sum0; - autoc[j+1] = sum1; - } - - if(j==lag){ - double sum = 1.0; - for(i=j-1; i<len; i+=2){ - sum += data[i ] * data[i-j ] - + data[i+1] * data[i-j+1]; - } - autoc[j] = sum; - } -} - -/** - * Quantize LPC coefficients - */ -static void quantize_lpc_coefs(double *lpc_in, int order, int precision, - int32_t *lpc_out, int *shift, int max_shift, int zero_shift) -{ - int i; - double cmax, error; - int32_t qmax; - int sh; - - /* define maximum levels */ - qmax = (1 << (precision - 1)) - 1; - - /* find maximum coefficient value */ - cmax = 0.0; - for(i=0; i<order; i++) { - cmax= FFMAX(cmax, fabs(lpc_in[i])); - } - - /* if maximum value quantizes to zero, return all zeros */ - if(cmax * (1 << max_shift) < 1.0) { - *shift = zero_shift; - memset(lpc_out, 0, sizeof(int32_t) * order); - return; - } - - /* calculate level shift which scales max coeff to available bits */ - sh = max_shift; - while((cmax * (1 << sh) > qmax) && (sh > 0)) { - sh--; - } - - /* since negative shift values are unsupported in decoder, scale down - coefficients instead */ - if(sh == 0 && cmax > qmax) { - double scale = ((double)qmax) / cmax; - for(i=0; i<order; i++) { - lpc_in[i] *= scale; - } - } - - /* output quantized coefficients and level shift */ - error=0; - for(i=0; i<order; i++) { - error -= lpc_in[i] * (1 << sh); - lpc_out[i] = av_clip(lrintf(error), -qmax, qmax); - error -= lpc_out[i]; - } - *shift = sh; -} - -static int estimate_best_order(double *ref, int min_order, int max_order) -{ - int i, est; - - est = min_order; - for(i=max_order-1; i>=min_order-1; i--) { - if(ref[i] > 0.10) { - est = i+1; - break; - } - } - return est; -} - -int ff_lpc_calc_ref_coefs(LPCContext *s, - const int32_t *samples, int order, double *ref) -{ - double autoc[MAX_LPC_ORDER + 1]; - - s->lpc_apply_welch_window(samples, s->blocksize, s->windowed_samples); - s->lpc_compute_autocorr(s->windowed_samples, s->blocksize, order, autoc); - compute_ref_coefs(autoc, order, ref, NULL); - - return order; -} - -/** - * Calculate LPC coefficients for multiple orders - * - * @param lpc_type LPC method for determining coefficients, - * see #FFLPCType for details - */ -int ff_lpc_calc_coefs(LPCContext *s, - const int32_t *samples, int blocksize, int min_order, - int max_order, int precision, - int32_t coefs[][MAX_LPC_ORDER], int *shift, - enum FFLPCType lpc_type, int lpc_passes, - int omethod, int max_shift, int zero_shift) -{ - double autoc[MAX_LPC_ORDER+1]; - double ref[MAX_LPC_ORDER]; - double lpc[MAX_LPC_ORDER][MAX_LPC_ORDER]; - int i, j, pass; - int opt_order; - - av_assert2(max_order >= MIN_LPC_ORDER && max_order <= MAX_LPC_ORDER && - lpc_type > FF_LPC_TYPE_FIXED); - - /* reinit LPC context if parameters have changed */ - if (blocksize != s->blocksize || max_order != s->max_order || - lpc_type != s->lpc_type) { - ff_lpc_end(s); - ff_lpc_init(s, blocksize, max_order, lpc_type); - } - - if (lpc_type == FF_LPC_TYPE_LEVINSON) { - s->lpc_apply_welch_window(samples, blocksize, s->windowed_samples); - - s->lpc_compute_autocorr(s->windowed_samples, blocksize, max_order, autoc); - - compute_lpc_coefs(autoc, max_order, &lpc[0][0], MAX_LPC_ORDER, 0, 1); - - for(i=0; i<max_order; i++) - ref[i] = fabs(lpc[i][i]); - } else if (lpc_type == FF_LPC_TYPE_CHOLESKY) { - LLSModel m[2]; - double var[MAX_LPC_ORDER+1], av_uninit(weight); - - if(lpc_passes <= 0) - lpc_passes = 2; - - for(pass=0; pass<lpc_passes; pass++){ - avpriv_init_lls(&m[pass&1], max_order); - - weight=0; - for(i=max_order; i<blocksize; i++){ - for(j=0; j<=max_order; j++) - var[j]= samples[i-j]; - - if(pass){ - double eval, inv, rinv; - eval= avpriv_evaluate_lls(&m[(pass-1)&1], var+1, max_order-1); - eval= (512>>pass) + fabs(eval - var[0]); - inv = 1/eval; - rinv = sqrt(inv); - for(j=0; j<=max_order; j++) - var[j] *= rinv; - weight += inv; - }else - weight++; - - avpriv_update_lls(&m[pass&1], var, 1.0); - } - avpriv_solve_lls(&m[pass&1], 0.001, 0); - } - - for(i=0; i<max_order; i++){ - for(j=0; j<max_order; j++) - lpc[i][j]=-m[(pass-1)&1].coeff[i][j]; - ref[i]= sqrt(m[(pass-1)&1].variance[i] / weight) * (blocksize - max_order) / 4000; - } - for(i=max_order-1; i>0; i--) - ref[i] = ref[i-1] - ref[i]; - } else - av_assert0(0); - opt_order = max_order; - - if(omethod == ORDER_METHOD_EST) { - opt_order = estimate_best_order(ref, min_order, max_order); - i = opt_order-1; - quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i], max_shift, zero_shift); - } else { - for(i=min_order-1; i<max_order; i++) { - quantize_lpc_coefs(lpc[i], i+1, precision, coefs[i], &shift[i], max_shift, zero_shift); - } - } - - return opt_order; -} - -av_cold int ff_lpc_init(LPCContext *s, int blocksize, int max_order, - enum FFLPCType lpc_type) -{ - s->blocksize = blocksize; - s->max_order = max_order; - s->lpc_type = lpc_type; - - if (lpc_type == FF_LPC_TYPE_LEVINSON) { - s->windowed_buffer = av_mallocz((blocksize + 2 + FFALIGN(max_order, 4)) * - sizeof(*s->windowed_samples)); - if (!s->windowed_buffer) - return AVERROR(ENOMEM); - s->windowed_samples = s->windowed_buffer + FFALIGN(max_order, 4); - } else { - s->windowed_samples = NULL; - } - - s->lpc_apply_welch_window = lpc_apply_welch_window_c; - s->lpc_compute_autocorr = lpc_compute_autocorr_c; - - if (ARCH_X86) - ff_lpc_init_x86(s); - - return 0; -} - -av_cold void ff_lpc_end(LPCContext *s) -{ - av_freep(&s->windowed_buffer); -} |
