VSE: Disk cache for audio waveform data

Often when I edit long videos consisting of multiple shots when I move around my session, Blender somehow drops it's waveform previews for sound strips and starts to generate them from scratch. This has a big performance impact and makes me unable to continue editing often for a few minutes, until it's done.

I wish Blender would dump these waveform previews on disk, so it can easily pick them up later if they were removed from the cache, because Blender has run out of RAM. The waveform cache could be treated similarly to Proxy files.

Ardour for example has a dedicated folder and it stores all waveform data (for display) so it can access that at any time, without the need to read all audio files all over again. And it works well. I've been editing sessions with multiple hours of audio with 8 GBs of RAM and it was working. It wasn't super smooth for different reasons, but the waveform disk cache does it's job.

It doesn't make sense to throw that data away and do all the costly disk read to load hundreds of megabytes of even gigabytes of data to produce the waveform previews anew from muxed video files. Better dump the 100 MB of that into a file for later reuse.