In Reply to: Asynchronous Sample Rate Conversion..... posted by Todd Krieger on May 12, 2006 at 21:31:34:
because rational fraction sample rate conversion is likely used and it is a completely synchronous process – the only “lost†information is the unavoidable bandwidth limiting lowpass filtering required to meet the Nyquist limit of the 44.1K output streamlogically you:
"upsample" and zero stuff 96K 147x
filter and decimate by 1/320 to 44.1K
but,
since you don't have to multiply out the "0" entries in the "upsampled" data in the filter and you only need to evaluate the filter for each output sample the actual fir bandlimiting/image reject filtering you need anyway doesn't cost much more except for fancy indexing
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Follow Ups
- No thats not an issue with Synchronous Rate Conversion - jcox 20:35:15 05/15/06 (3)
- Re: No thats not an issue with Synchronous Rate Conversion - Todd Krieger 01:27:01 05/16/06 (0)
- You are aware of "fast convolution" aren't you? - real_jj 12:54:26 05/25/06 (0)
- I haven't been inside any DAW code so I can't say what's used - jcox 10:23:41 05/16/06 (0)