On Tuesday 25 November 2003 10.39, Steve Harris wrote: > On Mon, Nov 24, 2003 at 08:21:55 +0100, David Olofson wrote: > > On Monday 24 November 2003 19.42, Frank Neumann wrote: > > [...] > > > > > I was wondering for a while when some older geek will start > > > porting/rewriting e.g. the old Amiga's narrator.device for > > > Linux - > > > > Actually, I was surfing around, looking for that a moment ago. > > Can't seem to find any source code, though. (Didn't really expect > > to.) Is it available? > > IIRC if was partly hardware - possibly just the phonomes blown onto > a chip - but you could look in one of the amiga emulator packages.
I looked pretty carefully at the docs and schematics back when I was hacking on the Amiga, and I never saw anything but the Paula chip (4 simple hardware DAC voices) when it comes to audio. I'm quite sure narrator.device used only the standard audio output driver. > > Yeah, that's another though... I guess one way would be to > > replace the synthesis stage of some current TTS system with a > > chip emulator style synth. Or how about hacking a LADSPA or JACK > > wrapper that generates control output that you can use to drive a > > modular synth? > > You can do fun things with formant filters (vowel peaks - theres a > dial that goes from A to EE) and envelope sequencers. > > If there isn't a formant filter for LADSPA allready available > someone should make one - the tables of co-efficients are available > online. I've seen some formant filter code somewhere... Can't remember if it was a LADSPA plugin, though. Anyway, formant filters might actually be a bit too sophisticated for what I want to do. I'd prefer something more similar to speech synthesis on old hybrid sound chips, like the 6581; that is, PWM, S&H noise and possibly a simple resonant filter. I've played some with *really* simple stuff, doing PWM on the PC speaker, and it's not too bad. "Colored" noise for the plosives is easy (PWM with random phase), and you can get a few vowels from just pure PWM. Adding an LPF, or alternative waveforms might do the trick. (A bit tricky to do with the PC speaker, of course, so I didn't try it back then. ;-) //David Olofson - Programmer, Composer, Open Source Advocate .- Audiality -----------------------------------------------. | Free/Open Source audio engine for games and multimedia. | | MIDI, modular synthesis, real time effects, scripting,... | `-----------------------------------> http://audiality.org -' --- http://olofson.net --- http://www.reologica.se ---
