wave playback trouble

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

hey y'all, i'm curious how this could possibly happen, it's quite strange.

my code looks like this. there's other stuff going on of course but this is really everything important.

SndBuf snd => dac;
"filename.wav" => snd.read;

while (true) {
1::second=>now;
}

now when i play some wave files it plays them back flawlessly. however, i tried playing back some .wav files that i made and it drops entire instruments out of the playback!! for example one song i wrote starts off with some violin and a drumbeat (and plays back as such in ITunes and Winamp) yet when i play it using this method, the violin cuts out entirely! i tried resaving and renaming the file, converting it to 48 KHz instead of 44.1, etc. etc. etc.

How can that even happen?

telstarmagikistferrari · Posted: Mon Nov 17, 2008 5:44 pm Post subject:

wow. in any case it sounds like a whole hell of a lot of weed was involved.
Shocked

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

well you are certainly correct about that good sir, but really...

if there is a way to strip individual instruments out of .wav files i'd like to know how!! i simply don't understand it.

EDIT i just copy-pasted the code above into a new file that does nothing but attempt to play a .wav and it still happens...

Kassen · Posted: Mon Nov 17, 2008 8:16 pm Post subject:

Ok. My bet is that this is a stereo file and these instruments are exactly 180° out of phase between the left and right channels, then canceling.

Could you try what happens if you use a mono version? If that turns out to be it we can then move on to making stereo work for you but I'd like to try this first.

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

huh.
i had a similar thought and try panning it all left or right and got no results.

but mono works fine... what am i doing wrong? i'm quite a noob at chuck and was just fooling around...

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

so does anybody know how to play a stereo file in chuck or am i stuck in mono?

Kassen · Posted: Fri Nov 21, 2008 2:31 pm Post subject:

I'm fairly sure this should work but I don't quickly have a stereo test file on this computer. Anyway, try this and see how far it gets you;

Kassen · Posted: Fri Nov 21, 2008 2:46 pm Post subject:

After giving it some more thought I now feel you were right to expect a automatic stereo connection. After all; Pan2 has a stereo output and that UGen automatically connects to the dac in stereo if chucked to it.

[edit]
After yet more thought I take that back :¬)
Unlike Pan2 SndBuf has no pre-determined number of channels; it may load a multi-channel wave files *after* it has been connected to the dac, so that would lead to issues.

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

thanks
but no dice. i get a null pointer from that code, maybe some minor error or oversight? i did try several other, similar methods to no avail tho.

EDIT

buf.chan(1) => dac.right;

causes the null pointer which is odd because if you read the number of channels in buf it gives back 2.

Kassen · Posted: Fri Nov 21, 2008 7:12 pm Post subject:

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

yeah i used exactly your code except changed the file name of course.

also i put in

buf.channels() =>int ch;
<<<ch>>>;

and it would say 2 channels on every test but when trying to access buf.chan(1) gives an error... weird.

Kassen · Posted: Fri Nov 21, 2008 8:11 pm Post subject:

Hmmmm, likely a bug but I just noticed that the docs on SndBuf don't actually mention .chan(). I suppose it could be that SndBuf is only meant to play a single channel but that you can pick which one you'd like to play from multi-channel files (creating the need to use two buf's for stereo). That sounds quite inconvenient though.

I suggest you report the issue to the mailing-list to make sure it's a bug but at the very least *something* is wrong here.

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

after a whole bunch of experimentation and a little bit of consulting the manual, here's how to play a stereo wave file in chuck -

SndBuf sndl;
"sound.wav" => sndl.read;
sndl.channel(0);
sndl=>dac.left;

SndBuf sndr;
"sound.wav" => sndr.read;
sndr.channel(1);
sndr=>dac.right;

hour => now;

probably i'll design a class for this tonight to be contained as one piece! thanks for your help kassen

telstarmagikistferrari · Posted: Mon Nov 24, 2008 5:33 pm Post subject:

this is great. well done. economical code! this will be endlessly useful.

Kassen · Posted: Mon Nov 24, 2008 7:42 pm Post subject:

A small suggestion;

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

hmmm.... strange i did try something like that and i kept getting this error, like "sndbuf[] has no element 'read()'" but now it's working fine with your code.. wonder what i did wrong. anyway, thanks!

Kassen · Posted: Tue Nov 25, 2008 11:41 am Post subject:

salamanderanagram · Joined: Apr 08, 2007 Posts: 20 Location: VT

nah i've been programming for 12 years, i understand usually all of this stuff... i must have been doing some esoteric error or stupid syntax mistake of some kind... thanks for the help!!