From efd1349a593ae609d44c4437c4dbb52a32269a5d Mon Sep 17 00:00:00 2001 From: Christopher Snowhill Date: Fri, 14 Jul 2023 04:10:10 -0700 Subject: [PATCH] Add an explanatory comment that got lost This comment was in the original sample decimator code, I neglected to include it in my port over to Cog. Doesn't really serve any functional change, though. It would have clarified that I needed to reduce the gain level much sooner, though. Signed-off-by: Christopher Snowhill --- Audio/Chain/ChunkList.m | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Audio/Chain/ChunkList.m b/Audio/Chain/ChunkList.m index bd3b793eb..2bfa92d48 100644 --- a/Audio/Chain/ChunkList.m +++ b/Audio/Chain/ChunkList.m @@ -28,6 +28,14 @@ * @author Sebastian Gesemann */ +/** + * This is the 2nd half of an even order symmetric FIR + * lowpass filter (to be used on a signal sampled at 44100*64 Hz) + * Passband is 0-24 kHz (ripples +/- 0.025 dB) + * Stopband starts at 176.4 kHz (rejection: 170 dB) + * The overall gain is 2.0 + */ + #define dsd2pcm_FILTER_COEFFS_COUNT 64 static const float dsd2pcm_FILTER_COEFFS[64] = { 0.09712411121659f, 0.09613438994044f, 0.09417884216316f, 0.09130441727307f,