Support
Looper's Delight
|
Support |
|
|
Travis Hartnett wrote: > In a non-RTOS, the overall response lag > may average at 1.5ms (although I seem to recall that Windows and Mac > OS take slightly longer than this), but there are times when another > task might have precedence, and so the looping app response drops down > to something like 20ms. Yes, I get this part. This doesn't explain why these timing inaccuracies "tend to get multiplied as the loop repeats". They don't, they stay exactly the same as the loop repeats. And it doesn't explain the concern over MIDI clocks that come in at 20ms intervals anyway and are always averaged. But one thing at a time. I can't deny that it is *possible* for there to be resource contention so severe that MIDI interrupt handlers are not called quickly, and that the millisecond timer is not maintained accurately. My contention is that it is *improbable* for this situation to exist if you are following all of the common sense rules for running audio applications on a PC. It is possible for you to get into an accident every time you drive a car, yet that doesn't prevent people from driving safely. Where did this 20ms number come from, did someone measure this in a controlled scientific experiment? How often did this anomaly occur, every 10 MIDI events? Every 100? Every 10,000? Were the suggestions on musicxp.net followed? Was the anomaly measured in the interrupt callback function passed to midiInOpen, or was it measured in an application thread processing untimestamped MIDI events? It is difficult to draw conclusions without something more concrete than "it is possible, therefore it must happen frequently, and the effect must be obvious". All I can say is that I don't get 20ms of jitter in the MIDI interrupt handler. It's more like 2 or 3. And I'm not even particularly careful about what else is running. I would think that if there were a frequent 20ms delay in MIDI event processing that we would be hearing something about that from the thousands upon thousands of keyboard players and percussionists that use soft synths. Maybe I just can't hear it. Eric Johnson claims he can determine the brand of battery in his Tube Screamer by the way it sounds. Some people are gifted :-) Jeff