Fixing audio sample rate conversion

Discuss SoundTrackers, shims to QTM, 32bitting and ARMv7 compatibility
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JonAbbott
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Joined: Thu Apr 11, 2013 12:13 pm
Location: Essex

Fixing audio sample rate conversion

Post by JonAbbott » Fri Aug 23, 2013 11:33 am

Seeing this thread on ROOL has reminded me that we'll need to deal with the issue of sample rate conversion at some point.

I'm guessing this wont be an issue for QTM where soundtrackers are used, unfortunately I don't have an OMAP machine to test on. For non-tracker based games we'll need to deal with it separately somehow, we can look at hijacking IRQ's and SWI's and simply double up the data to effectively half the sample rate. That does of course presume we're dealing with 22 to 44, any other odd rate conversions would probably need FFT / FHT to do it properly, but I don't think the ARM will be quick enough to do that 180+ times a second.

I coded a highly optimised FHT a few years back on the PC, so should we need it, it could be recompiled or rewritten in ARM.

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