02.10.2014 14:28, Tanu Kaskinen wrote: >>>>> Hmm... Now I see one weak point in this proposal: adding the new >>>>> attributes to ports, sinks and sources is perhaps not a very good idea, >>>>> because we might actually end up with a policy that uses some other >>>>> information for choosing the remixer than just the device, in which case >>>>> the new attributes would be meaningless or at least insufficient. For >>>>> example, whether or not to enable the virtual surround remixer depends >>>>> also on the stream channel map. >>>> >>>> I guess it is not a big problem if the remixers are allowed to say "I am >>>> not applicable" to this stream and output combination, in which case a >>>> fallback happens to the simple remixer. >>> >>> That would prevent the user from configuring the fallback parameters on >>> per-device basis. For example, if the user enables virtual surround on >>> some port, s/he wouldn't have control over what happens when playing a >>> stream where the virtual surround implementation doesn't apply. >> >> Then we are talking about a chain of fallbacks, or a list of effects to >> try. What if the configured fallback doesn't apply, too? > > Yes, we could have a list of remixers for each device, and fall back to > the simple remixer with settings from daemon.conf if none of the > remixers in the list work. > > However, the "try the listed remixers until one works" approach isn't > good if there are two remixers that both can be used, but one or the > other is preferred on some other criteria than just the device. For this > reason I'd prefer an approach where we have a policy module that allows > configuration with an extensible set of criteria. I don't have concrete > use cases for this, however, so if your taste says that it's better to > store the remixer preferences in the core device objects, because we'll > probably never need anything more flexible, then I don't have very > strong argument. My argument for the "list of things to try" is not strong either. So I think the best strategy is to continue the discussion later, when someone actually tries to implement some policy. -- Alexander E. Patrakov
