Re: ExtAudioFile 4GB file size limitation on WAV files
Re: ExtAudioFile 4GB file size limitation on WAV files
- Subject: Re: ExtAudioFile 4GB file size limitation on WAV files
- From: Paul Davis <email@hidden>
- Date: Sat, 30 Apr 2011 08:43:46 -0400
On Sat, Apr 30, 2011 at 7:33 AM, Richard Dobson
<email@hidden> wrote:
> Sadly the anwser is simple - you can't. WAVE (and also the AIFF family) use
> 32bit numbers to hold chunk sizes in bytes, which gives you the 4GB limit
> (not even 4.3GB). Yes, there are alternatives that have been invented - RF64
> being one (endorsed by the AES and EBU despite being IMO a bad design which
> breaks all sorts of rules, but is touted as backwards compatible with WAVE),
> and w64 which is ex Sonic Foundry and is preferable as a relatively if
> under-documented clean design; but there is as far as I can tell little
> support for either of these outside the broadcast community.
w64 is well supported by libsndfile, so any software which uses it for
audio file i/o can handle this format. rf64 is pretty much as you say.
> Probably the
> big apps such as Nuendo support them.
on OS X, the obvious candidate is CAF, which is supported by
libsndfile and thus by a lot of open source software on a variety of
platforms. i'm not sure what the status of CAF support is by
proprietary non-apple applications or frameworks.
> Note that even 24bit WAVE is now beyond the original WAVE specification - it
> has to be in WAVEFORMATEXTENSIBLE format. Perhaps that is what you meant by
> "an extension"? - but it is still limited to 32bit sizes, and hence to the
> 4GB limit.
actually, there's nothing about the RIFF/WAVE spec that prevents one
from creating 24bit or even 32 bit (integer or float) WAVE files, but
for some reason microsoft decreed that such formats were not
officially conformant, even though they don't violate any aspect of
the spec. this is really annoying because quite a lot of windows
software has followed microsoft's decree and will refuse to open WAVE
files that follow the RIFF/WAVE spec but use these bit depths/sample
formats.
i find this really deeply shortsighted on microsoft's part. there's
nothing more annoying to me that hearing from another user of my
software that application foobar cannot open the WAVE+32 bit floating
point files that my software created, when the only thing that makes
this format "illegal" is a post-facto decree from MS that if the bit
depth is more than 16, you need to use WAVEFORMATEXTENSIBLE. its just
nonsense.
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