From 22e28216336da876e1fd17f380ce42eaf1446769 Mon Sep 17 00:00:00 2001
From: Tim Redfern <tim@eclectronics.org>
Date: Mon, 17 Feb 2014 13:36:38 +0000
Subject: chasing indexing error

---
 ffmpeg/libavcodec/lpc.c | 293 ------------------------------------------------
 1 file changed, 293 deletions(-)
 delete mode 100644 ffmpeg/libavcodec/lpc.c

(limited to 'ffmpeg/libavcodec/lpc.c')

diff --git a/ffmpeg/libavcodec/lpc.c b/ffmpeg/libavcodec/lpc.c
deleted file mode 100644
index a6f2377..0000000
--- a/ffmpeg/libavcodec/lpc.c
+++ /dev/null
@@ -1,293 +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/lls2.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 = 0;
-    int opt_order;
-
-    av_assert2(max_order >= MIN_LPC_ORDER && max_order <= MAX_LPC_ORDER &&
-           lpc_type > FF_LPC_TYPE_FIXED);
-    av_assert0(lpc_type == FF_LPC_TYPE_CHOLESKY || lpc_type == FF_LPC_TYPE_LEVINSON);
-
-    /* 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_passes <= 0)
-        lpc_passes = 2;
-
-    if (lpc_type == FF_LPC_TYPE_LEVINSON || (lpc_type == FF_LPC_TYPE_CHOLESKY && lpc_passes > 1)) {
-        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]);
-
-        pass++;
-    }
-
-    if (lpc_type == FF_LPC_TYPE_CHOLESKY) {
-        LLSModel2 m[2];
-        LOCAL_ALIGNED(32, double, var, [FFALIGN(MAX_LPC_ORDER+1,4)]);
-        double av_uninit(weight);
-        memset(var, 0, FFALIGN(MAX_LPC_ORDER+1,4)*sizeof(*var));
-
-        for(j=0; j<max_order; j++)
-            m[0].coeff[max_order-1][j] = -lpc[max_order-1][j];
-
-        for(; pass<lpc_passes; pass++){
-            avpriv_init_lls2(&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= m[pass&1].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++;
-
-                m[pass&1].update_lls(&m[pass&1], var);
-            }
-            avpriv_solve_lls2(&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];
-    }
-
-    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;
-
-    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);
-
-    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);
-}
-- 
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