From 9b64e5e0db2a778313bb873bb38f481ce40efe31 Mon Sep 17 00:00:00 2001 From: Chris Robinson Date: Thu, 26 Sep 2019 19:24:29 -0700 Subject: Implement a "fast" bsinc path This takes advantage of the fact than when increment <= 1 (when not down- sampling), the scale factor is always 0. As a result, the scale and scale-phase deltas never contribute to the filtered output. Removing those multiply+add operations cuts half of the work done by the inner loop. Sounds that do need to down-sample (when played with a high pitch, or is 48khz on 44.1khz output, for example), still go through the normal bsinc process. --- alc/converter.cpp | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'alc/converter.cpp') diff --git a/alc/converter.cpp b/alc/converter.cpp index 6622a997..b0efb839 100644 --- a/alc/converter.cpp +++ b/alc/converter.cpp @@ -171,7 +171,7 @@ SampleConverterPtr CreateSampleConverter(DevFmtType srcType, DevFmtType dstType, BsincPrepare(converter->mIncrement, &converter->mState.bsinc, &bsinc24); else if(resampler == Resampler::BSinc12) BsincPrepare(converter->mIncrement, &converter->mState.bsinc, &bsinc12); - converter->mResample = SelectResampler(resampler); + converter->mResample = SelectResampler(resampler, converter->mIncrement); } return converter; -- cgit v1.2.3