Glame Bandpass Filter
IIR bandpass filter based using chebishev coefficients. The filter allows you to tweak the number of stages used for
filtering. Every stage adds two more poles, which leads to a steeper dropoff. More stages need more CPU power. This
filter was ported from the glame multitrack editor to ladspa.
sample_rate = s_rate;
ufc = (center + width*0.5f)/(float)sample_rate;
lfc = (center - width*0.5f)/(float)sample_rate;
combine_iir_stages(IIR_STAGE_BANDPASS, gt, first, second,
chebyshev(iirf, first, 2*CLAMP((int)stages,1,10), IIR_STAGE_LOWPASS, ufc, 0.5f),
chebyshev(iirf, second, 2*CLAMP((int)stages,1,10), IIR_STAGE_HIGHPASS, lfc, 0.5f));
iir_process_buffer_ns_5(iirf, gt, input, output, sample_count,RUN_ADDING);
ufc = (*(plugin_data->center) + *(plugin_data->width)*0.5f)/(float)sample_rate;
lfc = (*(plugin_data->center) - *(plugin_data->width)*0.5f)/(float)sample_rate;
first = init_iir_stage(IIR_STAGE_LOWPASS,10,3,2);
second = init_iir_stage(IIR_STAGE_HIGHPASS,10,3,2);
gt = init_iir_stage(IIR_STAGE_BANDPASS,20,3,2);
iirf = init_iirf_t(gt);
chebyshev(iirf, first, 2*CLAMP((int)(*(plugin_data->stages)),1,10), IIR_STAGE_LOWPASS, ufc, 0.5f);
chebyshev(iirf, second, 2*CLAMP((int)(*(plugin_data->stages)),1,10), IIR_STAGE_HIGHPASS, lfc, 0.5f);
combine_iir_stages(IIR_STAGE_BANDPASS, gt, first, second,0,0);
free_iirf_t(plugin_data->iirf, plugin_data->gt);
free_iir_stage(plugin_data->first);
free_iir_stage(plugin_data->second);
free_iir_stage(plugin_data->gt);
Center Frequency (Hz)
Bandwidth (Hz)
Stages(2 poles per stage)
Input
Output