Forums > MaxMSP

sfplay~ sporadically unresponsive to cues?

March 8, 2008 | 1:54 am

Hi,
I’ve got a strange issue i’m dealing with — I’m using a single long audio file with lots of sound events in it, and I’m playing back those sound events with an sfplay~ via preloaded cues. This mostly works great, but occasionally the sfplay~ doesn’t respond to a cue.

In other words, if I send it "40" it will usually play cue 40, but every once in a while I send it "40" and the sfplay~ object remains stubbornly silent.

Any advice?


March 8, 2008 | 5:22 pm

It’s most likely related to the disk buffer size you are using for
sfplay~. Before playing, sfplay~ reads a tiny chunk of the sound file,
the amount is based on this number. If reading the file from the disk
can’t keep up with the playback, then playback stops. Slower hard
drives often need larger numbers, and goes doubly so if you are
playing back at speeds > 1 or using multichannel files, but I’ve
experienced this on hard drives spinning at 7200 rpm, so it just
depends. It usually happens only at the start of playback, so if you
look at the position outlet of sfplay~ when this happens, I bet you’ll
see playback start for a split second, then stop.

Look in the sfplay~ help file and search the forum for more discussion
on this. I’ve always used (what I thought) were pretty large numbers
(262144), but recently ej chimed in saying he used buffer sizes over
1,000,000. Trade off is that it eats up memory…but that’s not so
much an issue these days…memory is pretty cheap and often abundant ;)

HTH,
David

On Mar 7, 2008, at 5:54 PM, Joseph Grimm wrote:

>
> Hi,
> I’ve got a strange issue i’m dealing with — I’m using a single long
> audio file with lots of sound events in it, and I’m playing back
> those sound events with an sfplay~ via preloaded cues. This mostly
> works great, but occasionally the sfplay~ doesn’t respond to a cue.
>
> In other words, if I send it "40" it will usually play cue 40, but
> every once in a while I send it "40" and the sfplay~ object remains
> stubbornly silent.
>
> Any advice?


March 9, 2008 | 5:21 am

Thanks David — I’ll try that.


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