Are there any free/open-source TTS options out there that are on the same level as Google Cloud's? I tried a lot of free ones, but they are absolutely awful and still sound like my Amiga did 30 years ago. With LLMs being available as open source, I am hoping there's also a good TTS offering I just haven't found yet.
Festival – not cutting edge – will definitely be better than your Amiga, and can handle long text. Last time I set it up, IIRC I wanted some voices generated by Tokyo University or something, which took some setting up. It'll probably be packaged in your Linux distro.
You can listen to a demo here.
https://www.cstr.ed.ac.uk/projects/festival/onlinedemo.html
It's not LLM-based.
For short snippets, offline, one can use Tortoise TTS – which is LLM based. But it's slow and can only generate clips of a limited length. Whether it's reasonable for you will depend a lot on your application. It will let one clone – or make a voice sounding more-or-less similar – a voice using some sound samples from them speaking.
https://github.com/neonbjb/tortoise-tts
Examples at:
https://nonint.com/static/tortoise_v2_examples.html
I haven't used Google's, but I'd assume, given that Google is paying people to work on it full time, that whatever they've done probably sounds nicer. But, then not open source, so…shrugs
Ah, I looked at Tortoise, but I do not have an nVidia GPU, so I couldn't try it. Festival I tried and the results were bad. Not so much for the voice, but for intonation and pronunciation.
I use it on an AMD GPU.
EDIT: Wait, let me make sure. I was using an Nvidia GPU for a while and switched to AMD.
EDIT2: Oh, yeah, it uses transformers, and that doesn't work on rocm presently, IIRC.