David Olofson wrote: >> you absolutely need ppq for the tick system to properly map >> different measures (5/4 time, 6/8 time etc) as per previous >> post. > >I'm not sure if you absolutely need it (you *can* translate), but >indeed, it's *much* nicer when the "speed" of musical time depends >only on tempo, and not the whole meter.
right on. >> add seconds-per-beat for plugins that are not limited to >> audio purposes. > >How about checking the audio sample rate? (Yes, that will not map >exactly to seconds, but it *would* allow you to have the same idea of >"1 second" as your wordclock sync'ed audio devices, which seems much >more useful to me.) > >If you want to deal with *actual* wall clock time to do some I/O, >you're in the wrong thread (host audio thread) and/or asking the >wrong questions, I think. seconds_per_tick is what i actually use, and it's central to easily mapping ticks to seconds, and from there to frames. seconds-per-beat would be a little exotic actually, sorry for bringing it into play. >Anyone here ever used non-integer # of beats/bar, and/or "weird" note >lengths? non-integer is not proven to be needed i think. if you say you need 9.5 beats per measure, simple make that 19 half beats. it is a lot simpler to implement on a machine, and the denominator is just a matter of convention but not of precision. >> * time in seconds > >What time? Wall clock? If you have the current time info struct, >it'll contain that (as calculated by the timeline "driver", based on >audio latency), and then you can convert back and fort as you like >by, though musical time position/"tick". in a system where audio is the master clock, the time i mean is simply frames / sample_rate. >> a separate function. i have opted for the latter -- to keep >> things sane, b.b.f conversion is only done for ticks and >> vice versa though. > >Yeah, it's just that that would be a *lot* of calls if you want to >cover all combinations. Look at VST's VstTimeInfo, or whatever Paul's >corresponding struct in JACK is called; those cover what you need. i don't care how complicated you make it, it just has to be there. ;) besides it's ok by me to complicate life for host coders. it's the plugins that should get the better part of the deal. tim
