chirptest/chirp.h

   1 /********************************************************************
   2  *                                                                  *
   3  * THIS FILE IS PART OF THE OggGhost SOFTWARE CODEC SOURCE CODE.    *
   4  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
   5  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
   6  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
   7  *                                                                  *
   8  * THE OggGhost SOURCE CODE IS (C) COPYRIGHT 2007-2011              *
   9  * by the Xiph.Org Foundation http://www.xiph.org/                  *
  10  *                                                                  *
  11  ********************************************************************
  12
  13  function: research-grade chirp extraction code
  14  last mod: $Id$
  15
  16  ********************************************************************/
  17
  18 typedef struct {
  19   float A;  /* center amplitude (linear) */
  20   float W;  /* frequency (radians per sample, not cycles per block) */
  21   float P;  /* phase (radians) */
  22   float dA; /* amplitude modulation (linear change per sample) */
  23   float dW; /* frequency modulation (radians per sample^2) */
  24   float ddA; /* amplitude modulation (linear change per sample^2) */
  25   int label; /* used for tracking by outside code */
  26 } chirp;
  27
  28 extern int
  29 estimate_chirps(const float *x, /* unwindowed input to fit */
  30                 const float *window, /* window to apply to input/bases */
  31                 int len,        /* block length */
  32                 chirp *c,       /* list of chirp estimates/outputs */
  33                 int n,          /* number of chirps */
  34                 float fit_limit,/* minimum basis movement to continue iteration */
  35                 int iter_limit, /* maximum number of iterations */
  36                 int fit_gs,     /* Use Gauss-Seidel partial updates */
  37
  38                 int fitW,       /* fit the W parameter */
  39                 int fitdA,      /* fit the dA parameter */
  40                 int fitdW,      /* fit the dW parameter */
  41                 int fitddA,     /* fit the ddA parameter */
  42                 int nonlinear,  /* perform a linear fit (0),
  43                                    nonlinear fit recentering W only (1)
  44                                    nonlinear fit recentering W and dW (2) */
  45                 float fit_W_alpha, /* W alpha multiplier for nonlinear fit */
  46                 float fit_dW_alpha,/* dW alpha multiplier for nonlinear fit */
  47                 int symm_norm,     /* Use symmetric normalization optimization */
  48                 int bound_zero);   /* prevent W or dW from fitting to negative or
  49                                       greater-then-Nyquist frequencies */
  50
  51 extern void advance_chirps(chirp *c, int n, int len);
  52