[flac-dev] Support for ultra-high sample rates?

[Con Kolivas]

Hi.

I was wondering if there was any interest in extending the flac
container format to support sample rates above the 655k current limit.
Please note this is not for using ridiculously high sample rate
sourced audio for some imaginary audible benefit. I've been involved
in some experimentation with offline upsampling in software prior to
delivery to an external DAC as a way to bypass the DAC's internal
oversampling and found that wavpak is the only compressed container
format that supports the 705/768 sample rates but it is very poorly
supported and extremely slow during decompression, and fully
uncompressed WAV data is extremely cumbersome. Most DACs do appear to
turn off their anti-aliasing filters at sample rates above 192kHz so
384 may well be the limit of any theoretical benefit, but many DACs
now support input up to 768kHz (a very small number support even
higher.) Studio ADCs often record in the Mhz range, and although they
apparently always decimate as they sample, there may be a theoretical
use for the data as is. It would be nice if the flac container was
extensible to any arbitrary value for research purposes.

Thanks,
-ck