I’m looking for open-source text-to-speech (TTS) engines written purely in Java. That is no native calls or similar — pure Java only. Ideally with high-quality voices (see quality definition below), but also lower quality alternatives are okay as long as the source is available.
Does such an open source project exist?
By “high-quality” I mean “human sounding”, “non-robotic” and with end results roughly on par with these two English language examples: Example 1, Example 2
The only open source java TTS engine I am aware of is MARY which came out of research labs and universities. It has not been active for a while and I have not heard the quality of the output.