manzara@cpsc.ucalgary.ca (Leonard Manzara) (11/18/89)
Is there anyone out there doing sound synthesis programming for the NeXT? Most of my calls to NeXT's software support line results in the aural equivalent of blank stares. Specifically, I need help dealing with "snddriver" and its control over the DSP chip. It is poorly documented and no source seems to be available for it. Lower level routines to control the chip seem to be available (implied in /include/dsp/DSPObject.h) but no documentation exists, nor any indication of how these routines interact with the hardware, and with snddriver. I have managed to program the DSP to output sine waves and pulse waves with rudimentary control over a) the frequency, and b) when the sound begins and ends. This program bypasses the SoundKit and MusicKit altogether, since the ultimate aim is to develop speech synthesis applications. What I need to know is how to use snddriver to control the synthesis program in real time. For example, as a waveform is being played I want to move a slider on the screen to change the waveform's frequency. Will snddriver allow me to do this or will I have to use the lower level routines? Also, has the DSP initiated Host to DSP DMA transfer protocol been implemented yet? The manual says that it will be but is documented (?!) for the time being only for the sake of completeness. Finally, does anyone know of technical documentation describing the D/A converter and related sound hardware? Is it really CD quality, and what type of filtering is used on output? NeXT really should do a better job of providing answers to these questions. Has anybody else managed to get satisfactory answers out of their support staff? Leonard Manzara (manzara@cpsc.UCalgary.CA)