text: /*
   * linear least squares model
   *
   * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   *
   * 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 AVUTIL_LLS_H
  #define AVUTIL_LLS_H
  
  #include "common.h"
  #include "mem.h"
  #include "version.h"
  
  #define MAX_VARS 32
  #define MAX_VARS_ALIGN FFALIGN(MAX_VARS+1,4)
  
  //FIXME avoid direct access to LLSModel2 from outside
  
  /**
   * Linear least squares model.
   */
  typedef struct LLSModel2 {
      DECLARE_ALIGNED(32, double, covariance[MAX_VARS_ALIGN][MAX_VARS_ALIGN]);
      DECLARE_ALIGNED(32, double, coeff[MAX_VARS][MAX_VARS]);
      double variance[MAX_VARS];
      int indep_count;
      /**
       * Take the outer-product of var[] with itself, and add to the covariance matrix.
       * @param m this context
       * @param var training samples, starting with the value to be predicted
       *            32-byte aligned, and any padding elements must be initialized
       *            (i.e not denormal/nan).
       */
      void (*update_lls)(struct LLSModel2 *m, double *var);
      /**
       * Inner product of var[] and the LPC coefs.
       * @param m this context
       * @param var training samples, excluding the value to be predicted. unaligned.
       * @param order lpc order
       */
      double (*evaluate_lls)(struct LLSModel2 *m, double *var, int order);
  } LLSModel2;
  
  void avpriv_init_lls2(LLSModel2 *m, int indep_count);
  void ff_init_lls_x86(LLSModel2 *m);
  void avpriv_solve_lls2(LLSModel2 *m, double threshold, unsigned short min_order);
  
  #endif /* AVUTIL_LLS_H */
  