model.py

from cvae import CVAE
import torch
from typing import Sequence
import streamlit as st
from lightning import LightningModule


def format_instruments(text: str) -> str:
    stems = text.split(" ")[1:]
    stems = [stem.replace(" ", "").lower() for stem in stems]
    return "_".join(stems)


def choice_to_tensor(choice: Sequence[str]) -> torch.Tensor:
    choice = "_".join([format_instruments(i) for i in choice])
    return torch.tensor(instruments.index(choice))


@st.cache_resource
def load_model(device: str) -> LightningModule:
    return CVAE.load_from_checkpoint(
        "epoch=77-step=2819778.ckpt",
        io_channels=1,
        io_features=16000 * 4,
        latent_features=5,
        channels=[32, 64, 128, 256, 512],
        num_classes=len(instruments),
        learning_rate=1e-5,
    ).to(device)


device = "cuda" if torch.cuda.is_available() else "cpu"

instruments = [
    "bass_acoustic",
    "brass_acoustic",
    "flute_acoustic",
    "guitar_acoustic",
    "keyboard_acoustic",
    "mallet_acoustic",
    "organ_acoustic",
    "reed_acoustic",
    "string_acoustic",
    "synth_lead_acoustic",
    "vocal_acoustic",
    "bass_synthetic",
    "brass_synthetic",
    "flute_synthetic",
    "guitar_synthetic",
    "keyboard_synthetic",
    "mallet_synthetic",
    "organ_synthetic",
    "reed_synthetic",
    "string_synthetic",
    "synth_lead_synthetic",
    "vocal_synthetic",
    "bass_electronic",
    "brass_electronic",
    "flute_electronic",
    "guitar_electronic",
    "keyboard_electronic",
    "mallet_electronic",
    "organ_electronic",
    "reed_electronic",
    "string_electronic",
    "synth_lead_electronic",
    "vocal_electronic",
]


model = load_model(device)


def generate(choice: Sequence[str], params: Sequence[int] = None):
    noise = (
        torch.tensor(params).unsqueeze(0).to(device)
        if params
        else torch.randn(1, 5).to(device)
    )
    return (
        model.sample(eps=noise, c=choice_to_tensor(choice).to(device)).cpu().numpy()[0]
    )