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Diffstat (limited to 'src/audacious/equalizer.c')
| -rw-r--r-- | src/audacious/equalizer.c | 214 |
1 files changed, 0 insertions, 214 deletions
diff --git a/src/audacious/equalizer.c b/src/audacious/equalizer.c deleted file mode 100644 index 1b74f31..0000000 --- a/src/audacious/equalizer.c +++ /dev/null @@ -1,214 +0,0 @@ -/* - * equalizer.c - * Copyright 2001 Anders Johansson - * Copyright 2010-2011 John Lindgren - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * 1. Redistributions of source code must retain the above copyright notice, - * this list of conditions, and the following disclaimer. - * - * 2. Redistributions in binary form must reproduce the above copyright notice, - * this list of conditions, and the following disclaimer in the documentation - * provided with the distribution. - * - * This software is provided "as is" and without any warranty, express or - * implied. In no event shall the authors be liable for any damages arising from - * the use of this software. - */ - -/* - * Anders Johansson prefers float *ptr; formatting. Please keep it that way. - * - tallica - */ - -#include <glib.h> -#include <math.h> -#include <pthread.h> -#include <string.h> - -#include <libaudcore/audstrings.h> -#include <libaudcore/hook.h> - -#include "equalizer.h" -#include "misc.h" -#include "types.h" - -#define EQ_BANDS AUD_EQUALIZER_NBANDS -#define MAX_CHANNELS 10 - -/* Q value for band-pass filters 1.2247 = (3/2)^(1/2) - * Gives 4 dB suppression at Fc*2 and Fc/2 */ -#define Q 1.2247449 - -/* Center frequencies for band-pass filters (Hz) */ -/* These are not the historical WinAmp frequencies, because the IIR filters used - * here are designed for each frequency to be twice the previous. Using WinAmp - * frequencies leads to too much gain in some bands and too little in others. */ -static const float CF[EQ_BANDS] = {31.25, 62.5, 125, 250, 500, 1000, 2000, - 4000, 8000, 16000}; - -static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; -static bool_t active; -static int channels, rate; -static float a[EQ_BANDS][2]; /* A weights */ -static float b[EQ_BANDS][2]; /* B weights */ -static float wqv[MAX_CHANNELS][EQ_BANDS][2]; /* Circular buffer for W data */ -static float gv[MAX_CHANNELS][EQ_BANDS]; /* Gain factor for each channel and band */ -static int K; /* Number of used eq bands */ - -/* 2nd order band-pass filter design */ -static void bp2 (float *a, float *b, float fc, float q) -{ - float th = 2 * M_PI * fc; - float C = (1 - tanf (th * q / 2)) / (1 + tanf (th * q / 2)); - - a[0] = (1 + C) * cosf (th); - a[1] = -C; - b[0] = (1 - C) / 2; - b[1] = -1.005; -} - -void eq_set_format (int new_channels, int new_rate) -{ - int k; - - pthread_mutex_lock (& mutex); - - channels = new_channels; - rate = new_rate; - - /* Calculate number of active filters */ - K = EQ_BANDS; - - while (CF[K - 1] > (float) rate / 2.2) - K --; - - /* Generate filter taps */ - for (k = 0; k < K; k ++) - bp2 (a[k], b[k], CF[k] / (float) rate, Q); - - /* Reset state */ - memset (wqv[0][0], 0, sizeof wqv); - - pthread_mutex_unlock (& mutex); -} - -static void eq_set_bands_real (double preamp, double *values) -{ - float adj[EQ_BANDS]; - for (int i = 0; i < EQ_BANDS; i ++) - adj[i] = preamp + values[i]; - - for (int c = 0; c < MAX_CHANNELS; c ++) - for (int i = 0; i < EQ_BANDS; i ++) - gv[c][i] = pow (10, adj[i] / 20) - 1; -} - -void eq_filter (float *data, int samples) -{ - int channel; - - pthread_mutex_lock (& mutex); - - if (! active) - { - pthread_mutex_unlock (& mutex); - return; - } - - for (channel = 0; channel < channels; channel ++) - { - float *g = gv[channel]; /* Gain factor */ - float *end = data + samples; - float *f; - - for (f = data + channel; f < end; f += channels) - { - int k; /* Frequency band index */ - float yt = *f; /* Current input sample */ - - for (k = 0; k < K; k ++) - { - /* Pointer to circular buffer wq */ - float *wq = wqv[channel][k]; - /* Calculate output from AR part of current filter */ - float w = yt * b[k][0] + wq[0] * a[k][0] + wq[1] * a[k][1]; - - /* Calculate output from MA part of current filter */ - yt += (w + wq[1] * b[k][1]) * g[k]; - - /* Update circular buffer */ - wq[1] = wq[0]; - wq[0] = w; - } - - /* Calculate output */ - *f = yt; - } - } - - pthread_mutex_unlock (& mutex); -} - -static void eq_update (void *data, void *user) -{ - pthread_mutex_lock (& mutex); - - active = get_bool (NULL, "equalizer_active"); - - double values[EQ_BANDS]; - eq_get_bands (values); - eq_set_bands_real (get_double (NULL, "equalizer_preamp"), values); - - pthread_mutex_unlock (& mutex); -} - -void eq_init (void) -{ - eq_update (NULL, NULL); - hook_associate ("set equalizer_active", eq_update, NULL); - hook_associate ("set equalizer_preamp", eq_update, NULL); - hook_associate ("set equalizer_bands", eq_update, NULL); -} - -void eq_cleanup (void) -{ - hook_dissociate ("set equalizer_active", eq_update); - hook_dissociate ("set equalizer_preamp", eq_update); - hook_dissociate ("set equalizer_bands", eq_update); -} - -void eq_set_bands (const double *values) -{ - char *string = double_array_to_str (values, EQ_BANDS); - g_return_if_fail (string); - set_str (NULL, "equalizer_bands", string); - str_unref (string); -} - -void eq_get_bands (double *values) -{ - memset (values, 0, sizeof (double) * EQ_BANDS); - char *string = get_str (NULL, "equalizer_bands"); - str_to_double_array (string, values, EQ_BANDS); - str_unref (string); -} - -void eq_set_band (int band, double value) -{ - g_return_if_fail (band >= 0 && band < EQ_BANDS); - double values[EQ_BANDS]; - eq_get_bands (values); - values[band] = value; - eq_set_bands (values); -} - -double eq_get_band (int band) -{ - g_return_val_if_fail (band >= 0 && band < EQ_BANDS, 0); - double values[EQ_BANDS]; - eq_get_bands (values); - return values[band]; -} |