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Diffstat (limited to 'ffmpeg/libavcodec/lpc.h')
| -rw-r--r-- | ffmpeg/libavcodec/lpc.h | 197 |
1 files changed, 0 insertions, 197 deletions
diff --git a/ffmpeg/libavcodec/lpc.h b/ffmpeg/libavcodec/lpc.h deleted file mode 100644 index c323230..0000000 --- a/ffmpeg/libavcodec/lpc.h +++ /dev/null @@ -1,197 +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 - */ - -#ifndef AVCODEC_LPC_H -#define AVCODEC_LPC_H - -#include <stdint.h> -#include "libavutil/avassert.h" - -#define ORDER_METHOD_EST 0 -#define ORDER_METHOD_2LEVEL 1 -#define ORDER_METHOD_4LEVEL 2 -#define ORDER_METHOD_8LEVEL 3 -#define ORDER_METHOD_SEARCH 4 -#define ORDER_METHOD_LOG 5 - -#define MIN_LPC_ORDER 1 -#define MAX_LPC_ORDER 32 - -/** - * LPC analysis type - */ -enum FFLPCType { - FF_LPC_TYPE_DEFAULT = -1, ///< use the codec default LPC type - FF_LPC_TYPE_NONE = 0, ///< do not use LPC prediction or use all zero coefficients - FF_LPC_TYPE_FIXED = 1, ///< fixed LPC coefficients - FF_LPC_TYPE_LEVINSON = 2, ///< Levinson-Durbin recursion - FF_LPC_TYPE_CHOLESKY = 3, ///< Cholesky factorization - FF_LPC_TYPE_NB , ///< Not part of ABI -}; - -typedef struct LPCContext { - int blocksize; - int max_order; - enum FFLPCType lpc_type; - double *windowed_buffer; - double *windowed_samples; - - /** - * Apply a Welch window to an array of input samples. - * The output samples have the same scale as the input, but are in double - * sample format. - * @param data input samples - * @param len number of input samples - * @param w_data output samples - */ - void (*lpc_apply_welch_window)(const int32_t *data, int len, - double *w_data); - /** - * Perform autocorrelation on input samples with delay of 0 to lag. - * @param data input samples. - * constraints: no alignment needed, but must have at - * least lag*sizeof(double) valid bytes preceding it, and - * size must be at least (len+1)*sizeof(double) if data is - * 16-byte aligned or (len+2)*sizeof(double) if data is - * unaligned. - * @param len number of input samples to process - * @param lag maximum delay to calculate - * @param autoc output autocorrelation coefficients. - * constraints: array size must be at least lag+1. - */ - void (*lpc_compute_autocorr)(const double *data, int len, int lag, - double *autoc); -} LPCContext; - - -/** - * Calculate LPC coefficients for multiple orders - */ -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); - -int ff_lpc_calc_ref_coefs(LPCContext *s, - const int32_t *samples, int order, double *ref); - -/** - * Initialize LPCContext. - */ -int ff_lpc_init(LPCContext *s, int blocksize, int max_order, - enum FFLPCType lpc_type); -void ff_lpc_init_x86(LPCContext *s); - -/** - * Uninitialize LPCContext. - */ -void ff_lpc_end(LPCContext *s); - -#ifdef LPC_USE_DOUBLE -#define LPC_TYPE double -#else -#define LPC_TYPE float -#endif - -/** - * Schur recursion. - * Produces reflection coefficients from autocorrelation data. - */ -static inline void compute_ref_coefs(const LPC_TYPE *autoc, int max_order, - LPC_TYPE *ref, LPC_TYPE *error) -{ - int i, j; - LPC_TYPE err; - LPC_TYPE gen0[MAX_LPC_ORDER], gen1[MAX_LPC_ORDER]; - - for (i = 0; i < max_order; i++) - gen0[i] = gen1[i] = autoc[i + 1]; - - err = autoc[0]; - ref[0] = -gen1[0] / err; - err += gen1[0] * ref[0]; - if (error) - error[0] = err; - for (i = 1; i < max_order; i++) { - for (j = 0; j < max_order - i; j++) { - gen1[j] = gen1[j + 1] + ref[i - 1] * gen0[j]; - gen0[j] = gen1[j + 1] * ref[i - 1] + gen0[j]; - } - ref[i] = -gen1[0] / err; - err += gen1[0] * ref[i]; - if (error) - error[i] = err; - } -} - -/** - * Levinson-Durbin recursion. - * Produce LPC coefficients from autocorrelation data. - */ -static inline int compute_lpc_coefs(const LPC_TYPE *autoc, int max_order, - LPC_TYPE *lpc, int lpc_stride, int fail, - int normalize) -{ - int i, j; - LPC_TYPE err; - LPC_TYPE *lpc_last = lpc; - - av_assert2(normalize || !fail); - - if (normalize) - err = *autoc++; - - if (fail && (autoc[max_order - 1] == 0 || err <= 0)) - return -1; - - for(i=0; i<max_order; i++) { - LPC_TYPE r = -autoc[i]; - - if (normalize) { - for(j=0; j<i; j++) - r -= lpc_last[j] * autoc[i-j-1]; - - r /= err; - err *= 1.0 - (r * r); - } - - lpc[i] = r; - - for(j=0; j < (i+1)>>1; j++) { - LPC_TYPE f = lpc_last[ j]; - LPC_TYPE b = lpc_last[i-1-j]; - lpc[ j] = f + r * b; - lpc[i-1-j] = b + r * f; - } - - if (fail && err < 0) - return -1; - - lpc_last = lpc; - lpc += lpc_stride; - } - - return 0; -} - -#endif /* AVCODEC_LPC_H */ |