Re: [ARSCLIST] BWF RF64

[Tom Fine <tflists@xxxxxxxxxxxxxxxxxxx>]

Hi Konrad:

This 2GB problem exists in Sony Soundforge too. Soundforge will record over an hour, it seems to go 
as long as it has spool room, but it won't save more than 2GB as a single file. Like you say, that's 
about 1 hour of stereo 96/24. I manually cut long files into 45 minute blocks, keeping some extra 
potential time in each file in case I want to splice in something.

-- Tom Fine

----- Original Message ----- 
From: "Konrad Strauss" <konrad.strauss@xxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Tuesday, September 04, 2007 10:28 PM
Subject: Re: [ARSCLIST] BWF RF64


on 9/4/07 5:07 PM, Eric Jacobs at EricJ@xxxxxxxxxxxxxxxxxxx wrote:

> Is anyone using BWF RF64 (RIFF 64 chunk) for large archival BWF files
> (larger than 4GB)?

We have done quite a bit of experimentation with file sizes and formats for
our live recording archives (click on the Blog link below for some entries
about what we're doing.)

Basically, there are major compatibility problems with any files larger than
2 GB. Pro Tools, for example, will not recognize a file over 2 GB.
Cuebase/Nuendo and Adobe Audition will happily record and play back 4 GB
files, and the resulting files will open and play in Wavelab. However if a
BWF file recorded in Wavelab exceeds 2 GB it will be corrupted - I forget
the exact behavior, but I think only part of it was playable.

When we did our tests, about a year ago, RF64 was supported only by Wavelab,
Cubase, Nuendo, and Pro Tools would not recognize the file as audio. We did
not test Adobe Audition and Soundforge. This may have changed since then.

So, to ensure compatibility we keep all files under 2 GB - about an hour of
recording time at 96/24 stereo interleaved. Generally this is no problem
(the split button in the Wavelab record window makes it pretty simple to do
on the fly.) Occasionally though, files end up being larger than 2 GB.
Operas for example can be difficult to split live, so we have the RF64
option checked in Wavelab's record settings to allow longer recordings. If
the live recording exceeds 2 GB, we split the files into < 2 GB chunks after
the recording is completed.

Our files are distributed to a number of destinations and so far there have
been no compatibility problems. We will probably reassess our procedures in
the near future, but until we see near-universal support for RF64, we will
continue to create < 2GB BWF files.

--
Konrad Strauss
Director of Recording Arts, Professor of Music
Indiana University Jacobs School of Music
http://php.indiana.edu/~kstrauss
http://www.music.indiana.edu/department/audio/
Blog ­ http://munson.music.indiana.edu/audioblog/
Podcast ­ http://www.music.indiana.edu/iumusiclive/authorize/podcasts.shtml