[Feature Request] Add support for BestSource

[Selur]

Do you know if using the option cachemode=0 will affect in some way the output quality/speed of BestSource ?

With cachemode=0, more ram will be used and loading of the source will be a bit slower since the cache will only be hold in ram, not on the disk.
Processing might be a bit faster, but it should have no impact on quality unless you have ram issues.

Cu Selur