So I'm getting a grip on using csound, and it's going pretty well.
There's just two places I'm hung up.
I can't apply effects to an incoming signal. I'd like to (as a simple example) apply chorusing and a light reverb to my own singing, an external synth, mic'ed guitar, etc. coming into csound, preferably in realtime so I can hear myself, and I'd also like to record it. I've had plenty of success putting global effects on traditional oscillator-based instruments within csound, and I can get my line in to work with virtually no latency just by tinkering with buffers and such in the csoptions field - but I can't get the signal modified.
I set a buffer and add -iadc and -odac. That works great, for the unprocessed input.
I've tried adding "-+realtimeaudio=alsa", but it doesn't appear to make a difference. (messages when I run csound appear to indicate realtime alsa's on anyway)
I have tried the "in" opcode as that appears to be the right place to get a mono signal into csound, and I am using something like "a1" as the argument, and I have a feeling this is part of the problem.
This is on an olpc from the console, as root - not that I have any other choice.
I am at work at the moment, but I will post an example later if someone needs to see what I'm talking about in more detail.
My other question is re: outputting multiple audio files when rendering to an audio file. Previously I'd used audacity or ecasound and worked with multiple audio files (one for each instrument, or maybe a submix for drums), then used effects and edited them appropriately, then mixed them all down to a single file. I'd love to do all my audio work in csound with a similar process. Is this possible, or am I better off just going back and forth between csound and ecasound? Ecasound is great for simple recording, but I really prefer csound over bash scripting for any kind of processing or mixing.
How about 'fout'?
I can't comment on the first part of your query, because my Ubuntu machine isn't set up for convenient audio input (just a matter of cabling, but not worth the effort at the moment). I suspect though that even a fast machine mightn't be able to do much real-time processing from input to output. All those buffers have to flow smoothly through, and as Csound is single-threaded that might be difficult. [As I said, though, I can't comment... (:-)]
To output 'multiple tracks' from Csound, I'd think the 'fout' opcode could do the job. You could either use its multitrack ability to create a multichannel AIFF file, and split the channels in audacity or something afterward, or use multiple fouts to write to several files at once. Got to admit I haven't tried this either, but from the manual it ought to work.
Thinking about this, though, it might even be simpler not to bother writing multiple files at once. After all, Csound's computations should be exactly reproduced for each run, so you could just run it sequentially several times with different parameters to create your multiple files (unless you're still wanting to do this with real-time input).