1
0
Fork 0

Avoid compressing DC bin on larger windows

Even if the DC filter is disabled. We do want to compress this on
smaller windows as it covers the entire bass range.
This commit is contained in:
Robbert van der Helm 2022-07-24 18:39:04 +02:00
parent 2a464c478c
commit 692b1051ad

View file

@ -351,8 +351,13 @@ impl Plugin for SpectralCompressor {
// The Hann window function spreads the DC signal out slightly, so we'll clear all 0-20 Hz
// bins for this. With small window sizes you probably don't want this as it would result in
// a significant low-pass filter. When it's disabled, the DC bin will also be compressed.
let first_non_dc_bin_idx = if self.params.global.dc_filter.value {
(20.0 / ((self.buffer_config.sample_rate / 2.0) / num_bins as f32)).floor() as usize + 1
let first_non_dc_bin_idx =
(20.0 / ((self.buffer_config.sample_rate / 2.0) / num_bins as f32)).floor() as usize
+ 1;
// Never compress the first bin on larger window sizes even if the DC filter is disabled
let dont_compress_below_bin_idx = if self.params.global.dc_filter.value || window_size > 256
{
first_non_dc_bin_idx
} else {
0
};
@ -399,13 +404,14 @@ impl Plugin for SpectralCompressor {
channel_idx,
&self.params,
overlap_times,
first_non_dc_bin_idx,
dont_compress_below_bin_idx,
);
// The DC and other low frequency bins doesn't contain much semantic meaning anymore
// after all of this, so it only ends up consuming headroom. If the DC filter is
// disabled then this won't do anything.
// after all of this, so it only ends up consuming headroom.
if self.params.global.dc_filter.value {
self.complex_fft_buffer[..first_non_dc_bin_idx].fill(Complex32::default());
}
// Inverse FFT back into the scratch buffer. This will be added to a ring buffer
// which gets written back to the host at a one block delay.