Re: [GD-General] Audio latency

[Thatcher U. <tu...@tu...>]

On Jun 30, 2004 at 12:44 -0400, Brian Hook wrote:
> > I'm thinking DDR here (Yes, I dance, in my living room, with a
> > computer.) there is no latency in the sense that it's one stream of
> > music and done.
> 
> Right, the idea I had was beat matching but where you actually play a
> sound on the beat instead of just matching the music that's there.
> I'm concerned that real latency issues are going to prevent that from
> being possible, except with a very hand coded, single platform
> implementation.

I think you should definitely be able to work around a reasonable
amount of latency using some game/audio design.  For example, let's
say you want to play a special drum sound when the user hits the
button at the right time.  But due to output audio latency and input
processing latency, you may not find out about the button-press until
after you need to start playing the drum sound.  So one trick would be
to design your game so that there is always a "null beat" sound that
plays when the user doesn't press the button.  Now, design the null
beat and the real beat so that the first 50ms, say, sound exactly the
same.  Then you're golden, you have enough time to substitute the rest
of either the null beat or the real beat right after the initial
attack.  Maybe this makes the real beat less satisfying to the player,
maybe not; that would have to be tested.

Or maybe a longish constant latency isn't actually so bad.
E.g. electric guitarists sometimes stand pretty far from their amps.
Sound travels about 1 foot per millisecond, so 20 feet ~= 20 ms.  I
don't know any drummers that stand 20 feet from their drums though.

It would be interesting to make a latency-adjustable virtual drum kit
and see how it feels.

-- 
Thatcher Ulrich
http://tulrich.com