Thanks for the answer! On Wed, Apr 6, 2016 at 1:39 PM, Tanu Kaskinen <tanuk at iki.fi> wrote: > On Tue, 2016-04-05 at 15:13 +0200, Lode Cools wrote: >> Hi, >> >> This topic has been touched before, but I did not find a conclusion: >> >> How does one create an end-user solution where it is possible to mix >> (select & combine) multiple sink-inputs into multiple sinks and then change >> this 'mix' selection dynamically (preferably glitch-free)? The changes >> would be performed using the D-Bus API (or any other API if that is >> required). > > Only the C API is "supported". The D-Bus API can be used too, but if > you have problems with it, you're on your own. The D-Bus API doesn't > have any stability guarantees, but in practice it's pretty stable, like > dead things tend to be. Yes. So far it has worked fine. > >> A simple example is: I am playing sink-input SI1 on combine-sink C1 which >> uses physical sink S1 as its slave. Now I also want to play sink-input SI1 >> on physical sink S2. >> >> For the moment, I know 2 ways to accomplish this dynamically: >> >> 1) 'create new combines' - approach >> * I create a new combine-sink C2 which uses both sink S1 and sink S2 as >> its slaves. Then I move the sink input SI1 from old combine-sink C1 to new >> combine-sink C2. Afterwards, I delete the old combine-sink C1. >> * Disadvantages: >> ** not glitch-free (especially for listeners of sink S1 who do not >> care about S2) >> >> 2) 'mute the unused links' - approach >> * I create from the beginning a 'full mesh': C1 uses both sink S1 and >> sink S2 as its slaves. 'playing a sink-input on a sink' then just >> translates to 'unmuting the sink-input from the combine-sink on the actual >> sink' >> * Disadvantages: >> ** when dealing with a lot of sink-inputs and sinks, the amount of >> 'links' is huge. If a muted input is also increasing the resample load >> (Can anyone confirm this statement?), this might be a resource-consuming >> solution. > > Yes, muted streams are resampled too. > >> ** all sinks need to be known upfront >> >> >> Ideally, there would be a solution where you could change the slaves of a >> combine-sink dynamically. But, afaik, this does not exist and is not >> planned either. > > It may not be planned, but patches implementing dynamic combine sink > slave management would definitely be welcome. > > module-combine-sink already supports dynamic slave changes internally, > because it has a mode where it plays to all sinks in the system, and > that requires automatically adding and removing outputs as sinks come > and go. OK. Understood. If it starts to become relevant for my intended application, I will implement this. How would the API look like? Is it enough to just catch changes on the sinks property list? > >> So the question is: Are solution 1 and 2 really the only solutions for my >> problem? > > I don't have any other solutions, apart from adding an API for the > combine sink slave management. > >> Which one of the solutions would you favor over the other? > > They have different tradeoffs, so which one is better depends on the > situation. > > -- > Tanu > _______________________________________________ > pulseaudio-discuss mailing list > pulseaudio-discuss at lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
