[Flac-dev] Re: More than 8 channels possible?

Brian Willoughby brianw at sounds.wa.com
Thu Mar 31 17:16:57 PST 2005


Are there any recording applications which create files with more than 8  
channels?  For that matter, are there any recording applications which create  
files with more than 2 channels?

I do a great deal of live multi-track recording.  Every tool I use creates  
mono recordings.  At most, I combine microphone pairs or stereo electronics  
channels into stereo files after recording.  Then, when backing up, I use FLAC  
to compress the mono and stereo files.  My recording software already organizes  
the files for one session into a directory, so the FLAC files live in that  
directory, too.

One way to save space is to use the "--no-padding" option.  Apart from  
padding, there is very little overhead in a FLAC file.  A theoretical  
16-channel FLAC file would not take any more space that 16 or fewer mono/stereo  
FLAC files, at least not if you combine related channels into stereo files.

How do you know what the storage requirements would be reduced?  The most  
savings comes from inter-channel correlation.  I doubt you'll really ever have  
more than four channels that actually have real correction in the audio.

NOTE: Adding support for more than 8 channels would increase the FLAC overhead  
by increasing the size of the header!

Brian Willoughby
Sound Consulting


Begin forwarded message:

Hello,

1. Would it be possible for FLAC to support more than 8 channels?
2. If (1) is not desirable because it would break compatibility or some
   such, then is it possible to build a local copy supporting more
   channels by simply increasing FLAC__MAX_CHANNELS in
   include/FLAC/format.h?

Either of these would greatly help in reducing the storage
requirements for recording sessions.

Thanks again.

Pascal.


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