Multichannel audio playback from disk

Jun 13, 2008 at 5:16am

Multichannel audio playback from disk

Hi,

I’d like to play back 24-channels of audio from disk with all of the channels perfectly in synch. Using 24 single-channel wav files is preferable, but I can also format the audio as a single 24-channel wav file (I’ve been using Audacity to do this). The audio is 32-bit at 48 kHz so the 24-channel file works out at about 3 GB, for the 11-minute piece I’m currently working with.

So far I’ve been trying to do this in Max 5 with sfplay~ and I have two specific questions:

(1) Is it possible to guarantee that 24 single-channel sfplay~ objects will start exactly together?

(2) I get an error when trying to load the 3GB 24-channel file into a 24-channel sfplay~ object, but I have been able to load a shorter file of around 300MB. Any ideas what the problem might be here?

And a more general one: assuming it is possible to get 24-channel playback with long files to work, can I realistically hope to get it working with 64-channels?

Thanks for any help,

Aengus.

#38383
Jun 13, 2008 at 6:43am

After trying a few more lengths of file, it looks like there might be a 2GB file size limit- anything under that seems to work. Also, it seems to be that any files that sfplay~ has problems with, also cause problems for sfinfo~, so maybe there’s some more general limit that I’m hitting. WinXP is the OS that I’m using, by the way.

Aengus.

#133822
Jun 13, 2008 at 9:10am

#133823
Jun 13, 2008 at 9:51am

64-channels I would like to hear that :-) sfplay~ has a limit of 16 tracks.

Also to go beyond the 4 GB (or 2 GB) file size limit we need Cycling to
support for the new file formats that uses 64-bit file offsets, like
Wav64, Riff64 or CAF.

I dont think there is any guarantee that multiple single channel files
will start in sync, so the groove~ method f.e mentions might be the way
to go. But question is if you have enough ram to read all the data into
buffers?

/J

jr.abstractions for MaxMSP – new version (2008-06-11)

http://www.sonicescape.net/maxmsp/

#133824
Jun 13, 2008 at 10:22am

Thanks for the replies.

According the Max 4.6 reference that I happen to have on the computer I’m sitting at, the sfplay~ limit is 28 channels. In Max 5, it only complained when I asked for > 32, so maybe the max number of channels is 32 in Max 5.

The multichannel playback is for ambisonic rendering, so synchronization between the different channels is vital.

The groove~ method is fine and there is enough RAM in this instance, but it might be necessary to deal with longer files in the future. This is why I’m investigating the options.

When I asked about 64-channels, I knew it was beyond the current capabilities of sfplay~, but are there any 3rd party objects or VST plugins which might help? For instance, there is a built-in object in AudioMulch which does multi channel playback from disk, where you can just give it the name of a mono wav file for each channel and it plays them back in synch. I’m not sure what its max number of channels is, but something like that, which can do 64-channels would be great. (maxobjects.com has not revealed anything.)

Cheers,

Aengus.

#133825
Jun 13, 2008 at 2:11pm

if i remember rightly (its been a while since i last did this), u can set the buffer size for sfplay~. This makes playing larger multi channel files less glitchy.

Also i’m pretty sure u can have sample accurate playback looping / cueing.

Take a good look at the sub patchers in the sfplay~ helpfile, it’s all in there!

#133826
Jun 13, 2008 at 2:26pm

Thanks Justin. I was following this thread with only one eye but I
had a look at the sfplay~ help file and learned a lot of things I can
use immediately. I really love this list.

Cheers
Gary Lee Nelson
TIMARA Department
Oberlin College
http://www.timara.oberlin.edu/GaryLeeNelson

On Jun 13, 2008, at 10:11 AM, justin wrote:

>
> if i remember rightly (its been a while since i last did this), u
> can set the buffer size for sfplay~. This makes playing larger
> multi channel files less glitchy.
>
> Also i’m pretty sure u can have sample accurate playback looping /
> cueing.
>
> Take a good look at the sub patchers in the sfplay~ helpfile, it’s
> all in there!

#133827
Jun 14, 2010 at 9:27pm

Hi Aengus,

Wondering if you ever got to the bottom of this…?

I’m trying to run long multi-channel files and running into the same problems.

http://cycling74.com/forums/topic.php?id=27088

Cheers,
Dave

#133828
Jan 6, 2012 at 7:31pm

hey, i have 6 audio channels, big ones, 2-3gig each (2hr recordings)
playback quality is not that important.
looking to play in sync between them.

whats my options?

#133830
Jan 7, 2012 at 11:47am

i did some more search, http://cycling74.com/forums/topic.php?id=24681
1. use soundFilesMerger from j–e http://www.e–j.com/?page_id=194
2. read into [splay~ 6]
3. hold hands

#133831
Jan 7, 2012 at 12:33pm

no. soundFilesMerger outputs a 59min file (original tracks are 2hr)
and when i try to open it in sfplay~ i get
“error opening output.aiff, err -1″
qt player plays it. but only the first hour…

#133832
Jan 7, 2012 at 2:23pm

more info:
getting separate audio feeds out of multivoice poly~ -http://www.cycling74.com/forums/topic.php?id=18546

syncing sfplay~s -http://www.cycling74.com/forums/topic.php?id=8656

#133833
Jan 8, 2012 at 3:30pm
#133834

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