Changeset 7380327

Timestamp:

Mar 8, 2014, 9:30:49 PM (11 years ago)

Author:

Paul Brossier <piem@piem.org>

Branches:

feature/autosink, feature/cnn, feature/cnn_org, feature/constantq, feature/crepe, feature/crepe_org, feature/pitchshift, feature/pydocstrings, feature/timestretch, fix/ffmpeg5, master, pitchshift, sampler, timestretch, yinfft+

Children:

5fe5591

Parents:

1e18df6

Message:

src/mathutils.h: add fvec_quadratic_peak_mag to find the magnitude of interpolated peaks

Location:

src

Files:

• mathutils.c (modified) (2 diffs)
• mathutils.h (modified) (2 diffs)

src/mathutils.c

@@ -1 +1 @@
 /*
-  Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org>
+  Copyright (C) 2003-2014 Paul Brossier <piem@aubio.org>
 
   This file is part of aubio.
@@ -430 +430 @@
 }
 
+smpl_t fvec_quadratic_peak_mag (fvec_t *x, smpl_t pos) {
+  smpl_t x0, x1, x2;
+  uint_t index = (uint_t)(pos - .5) + 1;
+  if (pos >= x->length || pos < 0.) return 0.;
+  if ((smpl_t)index == pos) return x->data[index];
+  x0 = x->data[index - 1];
+  x1 = x->data[index];
+  x2 = x->data[index + 1];
+  return x1 - .25 * (x0 - x2) * (pos - index);
+}
+
 uint_t fvec_peakpick(fvec_t * onset, uint_t pos) {
   uint_t tmp=0;

src/mathutils.h

@@ -1 +1 @@
 /*
-  Copyright (C) 2003-2013 Paul Brossier <piem@aubio.org>
+  Copyright (C) 2003-2014 Paul Brossier <piem@aubio.org>
 
   This file is part of aubio.
@@ -235 +235 @@
 smpl_t fvec_quadratic_peak_pos (fvec_t * x, uint_t p);
 
+/** finds magnitude of peak by quadratic interpolation
+
+  See [Quadratic Interpolation of Spectral
+  Peaks](https://ccrma.stanford.edu/~jos/sasp/Quadratic_Peak_Interpolation.html),
+  by Julius O. Smith III
+
+  \param x vector to get the magnitude of the interpolated peak position from
+  \param p index of the peak in vector `x`
+  \return magnitude of interpolated peak
+
+*/
+smpl_t fvec_quadratic_peak_mag (fvec_t * x, smpl_t p);
+
 /** Quadratic interpolation using Lagrange polynomial.