Fwd: render inNumberFrames vs. pre/postRender inNumberFrames
Fwd: render inNumberFrames vs. pre/postRender inNumberFrames
- Subject: Fwd: render inNumberFrames vs. pre/postRender inNumberFrames
- From: Evan Olcott <email@hidden>
- Date: Mon, 26 Jun 2006 19:05:56 -0500
I think this might count as a bug report, but I thought I'd check
here first:
---
I have an AUFormatter with it's render callback set to a routine in
my app, gathering data to render.
The same AUFormatter has a pre/post render notify callback attached
to it as well, assigning automation (in the pre-render, technically).
When I render a file who's sample rate is different than the
hardware's rate, I change the sample rate of the AUFormatter's
input stream, which gathers data accordingly:
- if the machine is running at 44.1kHz and the source file is
96kHz, the render call gets asked for the appropriate number of
samples (if the machine has a 512 sample buffer, the render call
gets asked for 1114+ samples at a time, which is fine)
However, the pre- and post- render callbacks always reference a 512
sample buffer! This makes me calculate the sample range
incorrectly, thus my ramped automation is off - I'm getting the
wrong length to work with.
Shouldn't the pre- render calls represent the number of samples
it's about to ask for, instead of the system's buffer size?
Would I be forced to do some "length math" to get the proper number
of samples about to be asked for so I can preRender my automation
properly?
Further reading shows that the *preRender* and *postRender* calls are
always in reference to the *output* of the audio unit to which they
are attached. That explains why I'm getting buffer size & info based
on the AUFomatter's output buffer size, not on what the AU is "about
to grab". Moderately inconvenient, but that's the way it is.
Just writing it out so it goes into the mailing list DB in case
someone searches for this.
-ev
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden