I’ve recently been doing some work with offline upsampling software that I modified to push the boundaries of upsampling and create highres flac files to play with Roon (using a sinc resampler with up to 1 billion taps). My DAC, along with many newer DACs, supports sample rates up to 768/24 but I soon realised that the flac container had a limit of 655kHz for its sample rate. I recently created a patch for the libflac code to support sample rates up to 1MHz which would not alter the flac container format at all. Hopefully it will be included in some form in the mainline flac code:
The best part of it is that the existing reference decoder library works seamlessly with it already. That means that my Roon supports these new flacs out of the box. It has allowed me to push the boundaries of my digital installation, and I’ve since moved all my DSP into Roon since it supports native sample rate convolution files, and I created one for every multiple of 44/48 up to 768, and made it far more complex than was achievable with a separate hardware solution. Here’s a screenshot of it in action, along with the insane convolution I use.
Thanks Roon for providing just the right tool for my insane setup. This runs on a separate roon server and I use a roon bridge locally to talk to my DAC and there is a continuous 50Mbit stream coming over the lan to use it without any issues.