Output quality was initially quite horrible, but turned out the phoneme stuff (espeak library) was not used but a brute force method. After I asked Codex to add the same library (a WASM port I think) and using that (already in the code now), the output quality should match the original exactly. The speed is not too bad on my Macbook Pro (M3) either.
Nice to see a real-world example of Codex handling a port like this. The browser first approach makes sense for TTS, being able to run it locally without a server is a big deal for privacy. Curious how the output quality compares to the original...?