Mike Brady
d043f98330
(1) to be multithreaded,
(2) to work on multichannel audio and
(3) to work on 48k and 44.1k audio.
Allow multiple impulse response (IR) files with a new setting: "convolution_ir_files"
When convolution starts, Shairport Sync will look for an IR file with a sample rate
matching the input (44.1k or 48k) and channel count.
If one can't be found, it will look for a single-channel IR file with the same rate.
It will always choose the first match in the file list supplied "convolution_ir_files".
Allow multithreading -- use the "convolution_thread_pool_size" to set the number of threads to use.
Deprecate "convolution" -- use "convolution_enabled" instead.
Deprecate "convolution_max_length" -- use "convolution_max_length_in_seconds" instead.
Deprecate "convolution_ir_file" -- use "convolution_ir_files" instead.
Update corresponding D-Bus methods and properties.
Update the loudness code to work on 48k and well as 44.1k audio and with multichannel audio.
Deprecate "loudness" -- use "loudness_enabled" instead.
Update corresponding D-Bus methods and properties.
Fix a deprecated FFmpeg warning.
Update HiFi-LoFi FFT convolver to latest available.
100 lines
3.3 KiB
C
100 lines
3.3 KiB
C
#include "loudness.h"
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#include "common.h"
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#include <math.h>
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#define MAXCHANNELS 8
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// loudness_processor_dynamic loudness_r;
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// loudness_processor_dynamic loudness_l;
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loudness_processor_dynamic loudness_filters[MAXCHANNELS];
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// if the rate or the loudness_reference_volume_db change, recalculate the
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// loudness volume parameters
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static int loudness_fix_volume_parameter = 0;
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static unsigned int loudness_rate_parameter = 0;
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static float loudness_volume_reference_parameter = 0.0;
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static loudness_processor_static lps = {0.0, 0.0, 0.0, 0.0, 0.0};
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void _loudness_set_volume(loudness_processor_static *p, float volume, unsigned int sample_rate) {
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float gain = -(volume - config.loudness_reference_volume_db) * 0.5;
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if (gain < 0) {
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gain = 0;
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}
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debug(2, "Volume: %.1f dB - Loudness gain @10Hz: %.1f dB", volume, gain);
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float Fc = 10.0;
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float Q = 0.5;
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// Formula from http://www.earlevel.com/main/2011/01/02/biquad-formulas/
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float Fs = sample_rate * 1.0;
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float K = tan(M_PI * Fc / Fs);
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float V = pow(10.0, gain / 20.0);
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float norm = 1 / (1 + 1 / Q * K + K * K);
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p->a0 = (1 + V / Q * K + K * K) * norm;
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p->a1 = 2 * (K * K - 1) * norm;
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p->a2 = (1 - V / Q * K + K * K) * norm;
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p->b1 = p->a1;
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p->b2 = (1 - 1 / Q * K + K * K) * norm;
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}
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float loudness_process(loudness_processor_dynamic *p, float i0) {
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float o0 = lps.a0 * i0 + lps.a1 * p->i1 + lps.a2 * p->i2 - lps.b1 * p->o1 - lps.b2 * p->o2;
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p->o2 = p->o1;
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p->o1 = o0;
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p->i2 = p->i1;
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p->i1 = i0;
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return o0;
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}
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void loudness_update(rtsp_conn_info *conn) {
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// first, see if loudness can be enabled
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int do_loudness = config.loudness_enabled;
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if ((config.output->parameters != NULL) && (config.output->parameters()->volume_range != NULL)) {
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do_loudness = 0; // if we are using external (usually hardware) volume controls.
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}
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if (do_loudness) {
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// check the volume parameters
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if ((conn->fix_volume != loudness_fix_volume_parameter) ||
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(conn->input_rate != loudness_rate_parameter) ||
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(config.loudness_reference_volume_db != loudness_volume_reference_parameter)) {
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debug(1, "update loudness parameters");
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float new_volume = 20 * log10((double)conn->fix_volume / 65536);
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_loudness_set_volume(&lps, new_volume, conn->input_rate);
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// _loudness_set_volume(&loudness_r, new_volume, conn->input_rate);
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loudness_fix_volume_parameter = conn->fix_volume;
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loudness_rate_parameter = conn->input_rate;
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loudness_volume_reference_parameter = config.loudness_reference_volume_db;
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}
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}
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conn->do_loudness = do_loudness;
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}
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void loudness_process_blocks(float *fbufs, unsigned int channel_length,
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unsigned int number_of_channels, float gain) {
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unsigned int channel_number, sample_index;
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float *sample_pointer = fbufs;
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for (channel_number = 0; channel_number < number_of_channels; channel_number++) {
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for (sample_index = 0; sample_index < channel_length; sample_index++) {
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*sample_pointer = loudness_process(&loudness_filters[channel_number], *sample_pointer * gain);
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sample_pointer++;
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}
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}
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}
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void loudness_reset() {
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unsigned int i;
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for (i = 0; i < MAXCHANNELS; i++) {
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loudness_filters[i].i1 = 0.0;
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loudness_filters[i].i2 = 0.0;
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loudness_filters[i].o1 = 0.0;
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loudness_filters[i].o2 = 0.0;
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}
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} |