vocodes_server.py - Runs as an HTTP server sidecar to the TTS jobs. It loads Tacotron and HifiGan models into memory and keeps an LRU cache. (The Rust job is responsible for managing which models are loaded into GPU memory.) Long term it would be better to quantize the models and not stand up a server to handle requests.
vocodes_model_check_tacotron.py - This checks newly uploaded models to make sure that they have the expected weights and dimensions. This will block invalid files from being uploaded (eg. video files).

To Run Tests

pytest text/

Vocodes Server Parameters

The vocodes_server.py HTTP server accepts HTTP POST requests to the /infer endpoint. The requests are JSON-encoded and have the following parameters:

inference_text - REQUIRED. The text to convert to speech.
synthesizer_checkpoint_path - REQUIRED. Where the Tacotron model lives on the filesystem.
vocoder_type - REQUIRED. Either hifigan-superres or waveglow.
waveglow_vocoder_checkpoint_path - OPTIONAL. Where the waveglow vocoder lives on the filesystem. Inference will use either Waveglow or HifiGan (preferred).
hifigan_vocoder_checkpoint_path - OPTIONAL. Where the HifiGan vocoder lives on the filesystem. Inference will use either Waveglow or HifiGan (preferred).
hifigan_superres_vocoder_checkpoint_path - OPTIONAL. Where the superres HifiGan vocoder lives on the filesystem. This can be used instead of HifiGan.
output_audio_filename - REQUIRED. The name of the output audio file. This controls where it is saved, which is important for the code that uploads it to GCP.
output_spectrogram_filename - REQUIRED. The name of the spectrogram file. This controls where it is saved, which is important for the code that uploads it to GCP.
output_metadata_filename - REQUIRED. The name of the metadata file. It contains stats such as audio duration. This controls where it is saved, which is important for the code that uploads it to GCP.
maybe_clear_synthesizer_checkpoint_path - OPTIONAL. Rust can instruct Python to remove models from memory.

This interface between Rust and Python can be changed at any time, of course.

TODO

Fix NeMo/ and nemo/ paths. These do not work on Macs as the filesystem is case-insensitive (ugh).