From 4e0fbe6077cafee9c6ff3fc1530544625b279de1 Mon Sep 17 00:00:00 2001 From: Paul Brossier Date: Thu, 17 Sep 2009 04:21:40 +0200 Subject: [PATCH] src/spectral/filterbank_mel.c: shorten counter variable names, improve comments, run through indent --- src/spectral/filterbank_mel.c | 103 +++++++++++++++++----------------- 1 file changed, 51 insertions(+), 52 deletions(-) diff --git a/src/spectral/filterbank_mel.c b/src/spectral/filterbank_mel.c index 5a6ef166..697e900b 100644 --- a/src/spectral/filterbank_mel.c +++ b/src/spectral/filterbank_mel.c @@ -33,7 +33,7 @@ aubio_filterbank_set_mel_coeffs (aubio_filterbank_t * fb, smpl_t samplerate, fvec_t *filters = aubio_filterbank_get_coeffs (fb); uint_t n_filters = filters->channels, win_s = filters->length; - //slaney params + /* Malcolm Slaney parameters */ smpl_t lowestFrequency = 133.3333; smpl_t linearSpacing = 66.66666666; smpl_t logSpacing = 1.0711703; @@ -42,101 +42,100 @@ aubio_filterbank_set_mel_coeffs (aubio_filterbank_t * fb, smpl_t samplerate, uint_t logFilters = 27; uint_t allFilters = linearFilters + logFilters; + /* throw a warning if filterbank object fb is too short */ if (allFilters > n_filters) { - AUBIO_WRN("not enough Mel filters, got %d but %d needed\n", + AUBIO_WRN ("not enough Mel filters, got %d but %d needed\n", n_filters, allFilters); } - //buffers for computing filter frequencies + /* buffers for computing filter frequencies */ fvec_t *freqs = new_fvec (allFilters + 2, 1); + /* convenience reference to lower/center/upper frequency for each triangle */ fvec_t *lower_freqs = new_fvec (allFilters, 1); fvec_t *upper_freqs = new_fvec (allFilters, 1); fvec_t *center_freqs = new_fvec (allFilters, 1); + /* height of each triangle */ fvec_t *triangle_heights = new_fvec (allFilters, 1); - //lookup table of each bin frequency in hz + + /* lookup table of each bin frequency in hz */ fvec_t *fft_freqs = new_fvec (win_s, 1); - uint_t filter_cnt, bin_cnt; + uint_t fn; /* filter counter */ + uint_t bin; /* bin counter */ - //first step: filling all the linear filter frequencies - for (filter_cnt = 0; filter_cnt < linearFilters; filter_cnt++) { - freqs->data[0][filter_cnt] = lowestFrequency + filter_cnt * linearSpacing; + /* first step: filling all the linear filter frequencies */ + for (fn = 0; fn < linearFilters; fn++) { + freqs->data[0][fn] = lowestFrequency + fn * linearSpacing; } - smpl_t lastlinearCF = freqs->data[0][filter_cnt - 1]; + smpl_t lastlinearCF = freqs->data[0][fn - 1]; - //second step: filling all the log filter frequencies - for (filter_cnt = 0; filter_cnt < logFilters + 2; filter_cnt++) { - freqs->data[0][filter_cnt + linearFilters] = - lastlinearCF * (POW(logSpacing, filter_cnt + 1)); + /* second step: filling all the log filter frequencies */ + for (fn = 0; fn < logFilters + 2; fn++) { + freqs->data[0][fn + linearFilters] = + lastlinearCF * (POW (logSpacing, fn + 1)); } - //Option 1. copying interesting values to lower_freqs, center_freqs and upper freqs arrays - //TODO: would be nicer to have a reference to freqs->data, anyway we do not care in this init step - - for (filter_cnt = 0; filter_cnt < allFilters; filter_cnt++) { - lower_freqs->data[0][filter_cnt] = freqs->data[0][filter_cnt]; - center_freqs->data[0][filter_cnt] = freqs->data[0][filter_cnt + 1]; - upper_freqs->data[0][filter_cnt] = freqs->data[0][filter_cnt + 2]; + /* fill up the lower/center/upper */ + for (fn = 0; fn < allFilters; fn++) { + lower_freqs->data[0][fn] = freqs->data[0][fn]; + center_freqs->data[0][fn] = freqs->data[0][fn + 1]; + upper_freqs->data[0][fn] = freqs->data[0][fn + 2]; } - //computing triangle heights so that each triangle has unit area - for (filter_cnt = 0; filter_cnt < allFilters; filter_cnt++) { - triangle_heights->data[0][filter_cnt] = - 2. / (upper_freqs->data[0][filter_cnt] - - lower_freqs->data[0][filter_cnt]); + /* compute triangle heights so that each triangle has unit area */ + for (fn = 0; fn < allFilters; fn++) { + triangle_heights->data[0][fn] = + 2. / (upper_freqs->data[0][fn] - lower_freqs->data[0][fn]); } - //filling the fft_freqs lookup table, which assigns the frequency in hz to each bin - for (bin_cnt = 0; bin_cnt < win_s; bin_cnt++) { - fft_freqs->data[0][bin_cnt] = aubio_bintofreq (bin_cnt, samplerate, win_s); + /* fill fft_freqs lookup table, which assigns the frequency in hz to each bin */ + for (bin = 0; bin < win_s; bin++) { + fft_freqs->data[0][bin] = aubio_bintofreq (bin, samplerate, win_s); } - - /* zeroing begining of filter */ - fvec_zeros(filters); + /* zeroing of all filters */ + fvec_zeros (filters); /* building each filter table */ - for (filter_cnt = 0; filter_cnt < n_filters; filter_cnt++) { + for (fn = 0; fn < n_filters; fn++) { /* skip first elements */ - for (bin_cnt = 0; bin_cnt < win_s - 1; bin_cnt++) { - if (fft_freqs->data[0][bin_cnt] <= lower_freqs->data[0][filter_cnt] && - fft_freqs->data[0][bin_cnt + 1] > lower_freqs->data[0][filter_cnt]) { + for (bin = 0; bin < win_s - 1; bin++) { + if (fft_freqs->data[0][bin] <= lower_freqs->data[0][fn] && + fft_freqs->data[0][bin + 1] > lower_freqs->data[0][fn]) { break; } } - bin_cnt++; + bin++; /* compute positive slope step size */ smpl_t riseInc = - triangle_heights->data[0][filter_cnt] / - (center_freqs->data[0][filter_cnt] - lower_freqs->data[0][filter_cnt]); + triangle_heights->data[0][fn] / + (center_freqs->data[0][fn] - lower_freqs->data[0][fn]); /* compute coefficients in positive slope */ - for (; bin_cnt < win_s - 1; bin_cnt++) { - filters->data[filter_cnt][bin_cnt] = - (fft_freqs->data[0][bin_cnt] - - lower_freqs->data[0][filter_cnt]) * riseInc; - - if (fft_freqs->data[0][bin_cnt + 1] > center_freqs->data[0][filter_cnt]) + for (; bin < win_s - 1; bin++) { + filters->data[fn][bin] = + (fft_freqs->data[0][bin] - lower_freqs->data[0][fn]) * riseInc; + + if (fft_freqs->data[0][bin + 1] > center_freqs->data[0][fn]) break; } - bin_cnt++; + bin++; /* compute negative slope step size */ smpl_t downInc = - triangle_heights->data[0][filter_cnt] / - (upper_freqs->data[0][filter_cnt] - center_freqs->data[0][filter_cnt]); + triangle_heights->data[0][fn] / + (upper_freqs->data[0][fn] - center_freqs->data[0][fn]); /* compute coefficents in negative slope */ - for (; bin_cnt < win_s - 1; bin_cnt++) { - filters->data[filter_cnt][bin_cnt] += - (upper_freqs->data[0][filter_cnt] - - fft_freqs->data[0][bin_cnt]) * downInc; + for (; bin < win_s - 1; bin++) { + filters->data[fn][bin] += + (upper_freqs->data[0][fn] - fft_freqs->data[0][bin]) * downInc; - if (fft_freqs->data[0][bin_cnt + 1] > upper_freqs->data[0][filter_cnt]) + if (fft_freqs->data[0][bin + 1] > upper_freqs->data[0][fn]) break; } /* nothing else to do */ -- 2.26.2