Re: "Friendly" setting sample rates
Re: "Friendly" setting sample rates
- Subject: Re: "Friendly" setting sample rates
- From: "Ross Bencina" <email@hidden>
- Date: Tue, 20 Oct 2009 13:26:45 +1100
Brian Willoughby wrote:
If the above is not sufficient, then perhaps you could have a
Preference setting which is Off by default, but when manually turned
On by the user, it would allow your application to set the sample
rate. Basically, this would be a "Professional" versus "Consumer"
setting. Most consumers don't really care whether their audio runs
through SRC. They just want everything to run smoothly, and the last
thing they want is for one application to force settings which could
interfere with another.
<<<
I think it depends how you define "consumer." The interesting thing is that
GarageBand is a consumer app, and even so, apparently it is forcing a fixed
sample rate. Perhaps it would be more appropriate to talk about "sound and
music production" apps, and "consumer media consumption" apps. Even the most
primitive consumer music production user may care what sample rate they're
recording at -- they don't need to be a mastering engineer.
I'm very interested if Apple has any guidelines for this, since the whole
multi-app SRC thing seems rather messy to me (not that I have a solution
:-).
For my users, it would be:
A) bad if they had explicitly selected 96k and they weren't getting it due
to SRC to the current sample rate
B) bad if they were warned that the sample rate couldn't be changed or they
had to go through some complex process to do it (users may not be
sophisticated enough to know what that means).
C) bad if all audio on their computer glitched when they started my app.
D) bad if they couldn't devote more than 50% CPU to audio because of SRC
related buffering/callback phase issues.
E) bad if the CPU consumption / available track count on my app (apparently
randomly) varied between programs runs depending on what the global system
default sample rate was
At the moment I force the sample rate on startup and put up with (C) (and
apparently, with problems if GarageBand or Logic is running at a different
sample rate), but its a tradeoff.
The only way I can think of resolving all of the above cleanly is for there
to be no way at all for any music production app (including GarageBand and
Logic) to set the sample rate -- that way the users who cared would always
know to go to the system settings to adjust the sample rate and everything
would always interoperate cleanly.
Ross.
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