Forums > MaxMSP

two sfreocrd~ – duration of one file longer than other

Mar 24 2009 | 10:26 pm

Hi all,
Having a slight problem with sfrecord~ (included patch) when recording to two audio files. I’ve noticed that the duration of one of the output wave files is longer than the other. However, during recording, both show that they are the same length until you press stop (toggle the start/stop) and then there is a slight pause (i’m guessing this pause is maxmsp closing the file(s)?) and then the durations change.

Is this a bug or have i done something wrong? Or is it possible that one file is stopped (and closed) before the other? As i’ve tried a mixture of IDE and SATA drives (old and new) and it doesn’t seem to make a difference.

Cheers for any help!

(p.s – I’m using 5.0.6 or XP64)

— Pasted Max Patch, click to expand. —
Mar 24 2009 | 10:37 pm

Not sure about what’s causing the problem (how big is the difference? is it always the same amount, or does it vary?)

Could you record your audio to a single multi-channel file (sfrecord allows up to 8 or 16 channels, not sure, but I know it can do 4) and then split it later?

Mar 25 2009 | 1:31 am

The difference isn’t consistent, it varies from roughly half a second to a second and a half. So im assuming maxmsp stops one sfrecord and waits until the files closes before stopping the other, even when the stop/start ‘bang’ toggle has been sent to both.

I did try a multi-channel wave file (using ‘sfrecord~ 4’), but it only seems to store 2 channels – have tried it in Audacity, Audition and Cubase LE and i’m sure one of those supports multi-channel waves.

It’s not a problem as i’m dealing with mono channels whilst doing some checking on phasing issues, but i found it a little odd that it happened.

Mar 29 2009 | 7:52 am

I guess its a bug. Stop recording (writing samples to disc) and closing the file should be two different things with different priorities. I have seen this as well, not with multiple sfrecord~, but a single one would record longer than it is supposed to…
The starting points are correct though, that’s why it never bothered me…

I hope that the support is monitoring the forum in the same way as the list, for them it must be harder with the forum as well…
(hint: a reply to this post would proof it…Wink


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Forums > MaxMSP