Plaits custom LPC with BlueWizard

I recently used BlueWizard to generate code for new LPC words in Plaits. Took me a bit of trial and error, but I got it working.

However, I noticed that certain phrases don’t end properly, meaning the last tone continues to play endlessly. Was wondering if anyone had details on this, as I am new to the TI/LPC speech synthesis.

I told BlueWizard to add the 0x to the output codes, and put in specific end of word frames. (The latter being something that stumped me for a while!). I also changed the BlueWizard code to output the number of bytes, so it makes updating the array lengths in Plaits a bit easier (that also stumped me, cause there are two places with the array length)

I also tried a bunch of different random things like using different voices on the OSX wav generator. But when I use certain phrases, the final tone continues endlessly. Other phrases work fine!

Anyway, just curious if others have been hacking on the LPC words in Plaits, would love to hear about your results.


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Maybe the array length sometimes doesn’t include the stop frame, so Plaits stops reading the LPC data before it reaches that point. Just a thought…

Yeah I thought the same, but I have modified the BlueWizard code to output the number of frames, and can see it go up when I click the ‘end of word’ frame checkbox. So I think it is including it properly. Also, I noticed that when the end frame is wrong, the whole module kinda freaks out. For example, when you switch to the speech model, it pauses, outputs a high pitched tone, or you can’t switch out of the speech model. (Makes sense if there was an array length issue). When I have the lengths correct, the model switching works right.

I noticed in BlueWizard, for the phrases that have this issue, the waveform on the right (the LPC one) is not zero at the end. I tried crazy things like just putting some zeroes at the end, but alas, no luck. Prob just me not understanding the speech synthesis algorithm…

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