Broadcast Wave (BWF) does not really have anything to do with any
limitation of WAVE files > 2 GB. Both BWF and WAV formats have the
same limitation of 4 GB. What you're probably familiar with are
certain older WAV software packages which incorrectly implement WAVE
and/or which do not properly use the underlying operating system for
accessing files with more than 2 GB - e.g. API with a signed 32-bit
value for offset cannot seek beyond 2 GB, and thus the WAVE code must
use system calls which support 4 GB seeks via unsigned 32-bit
parameters. However, many BWF implementations are newer, and thus
they typically do not make the mistake of accidently limiting the
size to 2 GB. It's not the BWF part of the support that makes this
work, but the fact that it is a newer implementation of the old WAVE
standard.
In other words, as far as I know, you should be able to create a
standard WAVE file with CoreAudio AudioFile API up to 4 GB in total
file size - i.e. slightly less than 4 GB of samples, given the
overhead of the format itself. There is no particular advantage to
BWF support in terms of file size - Broadcast Wave does not fix the 2
GB limit of certain OS calls and does not offer any advantage in file
size compared to WAVE.
Brian Willoughby
Sound Consulting
On Jan 7, 2008, at 19:36, Dominic Feira wrote:
Is there any support in Core Audio for writing WAVE files > 2GB in
length (e.g. Broadcast Wave)? If not, I guess its file component
writing time.
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
http://lists.apple.com/mailman/options/coreaudio-api/email@hidden
