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Re: Format mismatch
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Re: Format mismatch


  • Subject: Re: Format mismatch
  • From: kelly jacklin <email@hidden>
  • Date: Mon, 4 Oct 2004 09:12:49 -0700

On Oct 4, 2004, at 8:54 AM, Mark's Studio wrote:

My problem is that my processing is altivec unrolled by 8 so im skipping samples,is there a smart way to buffer the data and only call my altivec function when there is enough frames ?

As for the SRC at the end, im not sure it's the best solution since the processing can't compensate for the artifacts introduced by the SRC.

The point is arguable, but regardless as an AU, you cannot control where the host does SRC, so you must be prepared for this situation in real host apps.


Furthermore there are devices that actually have non-altivec-grained buffer frame counts (for example certain video/audio muxed devices, which have a 160{1,2} cadence samples per frame, and pull one buffer per frame). You need to be able to handle non-altivec-grained buffers...

The way this is typically handled is for the altivec code to run through loops for the altivec-grained (or even greater, if your processing is unrolled) part of the buffer, and then run through a scalar version for the remaining samples. Buffering the data would involve artificially introducing latency into your AU (which you must report correctly, for hosts to be able to compensate properly for the latency you are imposing)...

Assuming you will always be presented with altivec-grained buffers will fail with shipping hosts and drivers today.

kelly

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  • Follow-Ups:
    • Re: Format mismatch
      • From: kelly jacklin <email@hidden>
References: 
 >Format mismatch (From: "Mark's Studio" <email@hidden>)
 >Re: Format mismatch (From: kelly jacklin <email@hidden>)
 >Re: Format mismatch (From: "Mark's Studio" <email@hidden>)

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