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Duh, just use resample_factor_reciprocal

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The resample_factor_reciprocal also happens to be our
anti-alias cutoff. In this case it represents the minimum
output bandwidth needed to fully represent the input.
This commit is contained in:
JasonLG1979 2023-07-02 22:13:20 -05:00
parent 87bbd539b7
commit cb8f6c954d
1 changed files with 4 additions and 8 deletions
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12
playback/src/config.rs
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@ -26,13 +26,6 @@ const HZ88200_INTERPOLATION_OUTPUT_SIZE: usize =
const HZ96000_INTERPOLATION_OUTPUT_SIZE: usize =
(RESAMPLER_INPUT_SIZE as f64 * (1.0 / HZ96000_RESAMPLE_FACTOR_RECIPROCAL)) as usize;
// This is the bandwidth of the output.
// Even at 48kHz it still translates to 100% source bandwidth.
// This just provides a little bit of anti-alias filtering.
// There is more then likely nothing there to filter,
// but it doesn't hurt or cost us anything to make sure.
const WINDOWED_SINC_INTERPOLATION_BANDWIDTH: f64 = 0.92;
// Blackman Window coefficients
const BLACKMAN_A0: f64 = 0.42;
const BLACKMAN_A1: f64 = 0.5;
@ -99,7 +92,10 @@ impl InterpolationQuality {
let index_float = interpolation_coefficient_index as f64;
let sample_index_fractional = (index_float * resample_factor_reciprocal).fract();
let sinc_center_offset =
(index_float - sinc_center) * WINDOWED_SINC_INTERPOLATION_BANDWIDTH;
// The resample_factor_reciprocal also happens to be our
// anti-alias cutoff. In this case it represents the minimum
// output bandwidth needed to fully represent the input.
(index_float - sinc_center) * resample_factor_reciprocal;
let sample_index_fractional_sinc_weight = Self::sinc(sample_index_fractional);