Wednesday, October 06, 2004

lab 10 - delay


lab 10 - delay line


I am continuing to add signal modules to signalfs copying the implementations from stk. Today I'm working on the delay line, and whatever else I can implement in two hours.

The delay line does not fit the model of signals I have created so far. From the STK it looks like it is used more as a utilitly class than a standalone filter. Its used by the echo class which actually does the mix of the current input with the delayed input. I could of course do the same thing and have delay as functions with the dsp module. Trying to use the delay, or echo, brings up a number of issues.

How am I going to stack multiple filters ontop one another and still be able to ctrl each one independently? To access to each ctl file I'd need to know the conversation number. This might be tricky to find out if I have multiple instruments each being built from many modules.

I want to alter the effect during playback independently of the instrument being played. But I'm not sure how to fit it in with a simple instrument. Where in the stack should it go? And how will I control it if it's placed under the instrument?

This goes back to the problem of needing some kind of patch bay. Given a particular instrument we need to now all the effects tied in to it. Then we want to write to the ctl file of any of them, not via the instrument but directly, and alter the effect. We need to remove the exclusive access condition on the ctl, although we could place it on data instead.

If I didn't do this I'd need a naming convention within the ctl file that was at the end of the filter pipeline. But that is ridiculous because what else am I using a fs for.

Therefore, If I put the, say, echo filter in front of the instrument, I still send note events to the instrument, but read sound back from the echo data file.

Is the sequencer going to be able to manage all this? The skini language may have to include naming of instruments using filenames. That is, events are sent directed to specified ctl files (filters, instruments) but audio data is read from only one, the one at the end of the pipeline (is pipeline the right term here? filter chain, patch? sink?).

I need to specify the sequencer language and a means for retrieving all the conversation directories for a pipeline before going further.


delay.b delayl.b

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