On Fri, 2006-04-07 at 14:23 -0800, Patrick Stinson wrote: > As an added note to my previous comments, I really like the app > interface that mpd uses. Writing ascii events using some spec or > another to a file descriptor (socket in mpd's case) seems to be a > terrific way to communicated with apps and libs. I run the svn > pksampler like this: > > pksampler | pkaudiod > > I could just as easily have either use a socket or some other pipe, > and this is easy to debug, script, profile, etc. On the client and > server sides, I wrap my 10-minute rpc into an interface with generic > calls. Everything having to do with input (MIDI, OSC, whatever) > happens in the app code. The interface functions resemble those of > FMODEx's interface; add sample, connect to channel, set sample attrs, > etc. > > As an interface designer, the first thing I look for on an engine's > project site is some sort of asynchronous API - I should never concern > myself with anything outside referencing the api from my app's one > windowing thread. FMOD, gstreamer, and my dead pkaudio project do this > very well. I don't ever want to worry about what thread it happens in, > what threads it will affect, or what the performance effects of > *making* the call will be (as opposed to residual effects).
although i agree that this is the right design for many classes of application design, i would like to see how you propose to tackle metering and waveform display (the two most difficult examples). ardour would be relatively easy to separate into interface+engine processes (as opposed to just a lib/lib-client separation) if it were not for these issues. moving waveform and metering data back and forth between two processes via a wire protocol is very expensive and inefficient. --p
