Accelerating High-Fidelity Waveform Generation via Adversarial Flow Matching Optimization
Sang-Hoon Lee, Ha-Yeong Choi, Seong-Whan Lee
TL;DR
This work addresses the slow sampling and limited high-frequency fidelity of conditional flow matching (CFM) for waveform generation. It introduces PeriodWave-Turbo, which finetunes a pre-trained CFM generator into a fixed-step, few-step ODE sampler using reconstruction losses and adversarial feedback, achieving state-of-the-art objective and subjective scores with 2–4 inference steps and a 1,000-step fine-tuning regime. Key innovations include a fixed-step generator, a multi-term loss combining adversarial, reconstruction, and feature-matching objectives, and a study across model sizes (S/B/L) that scales performance while maintaining efficiency. The approach delivers substantial speedups, improves PESQ on LibriTTS to around $4.454$, and demonstrates robustness in OOD and two-stage TTS scenarios, with plans to release code and checkpoints for reproducibility and broader impact.
Abstract
This paper introduces PeriodWave-Turbo, a high-fidelity and high-efficient waveform generation model via adversarial flow matching optimization. Recently, conditional flow matching (CFM) generative models have been successfully adopted for waveform generation tasks, leveraging a single vector field estimation objective for training. Although these models can generate high-fidelity waveform signals, they require significantly more ODE steps compared to GAN-based models, which only need a single generation step. Additionally, the generated samples often lack high-frequency information due to noisy vector field estimation, which fails to ensure high-frequency reproduction. To address this limitation, we enhance pre-trained CFM-based generative models by incorporating a fixed-step generator modification. We utilized reconstruction losses and adversarial feedback to accelerate high-fidelity waveform generation. Through adversarial flow matching optimization, it only requires 1,000 steps of fine-tuning to achieve state-of-the-art performance across various objective metrics. Moreover, we significantly reduce inference speed from 16 steps to 2 or 4 steps. Additionally, by scaling up the backbone of PeriodWave from 29M to 70M parameters for improved generalization, PeriodWave-Turbo achieves unprecedented performance, with a perceptual evaluation of speech quality (PESQ) score of 4.454 on the LibriTTS dataset. Audio samples, source code and checkpoints will be available at https://github.com/sh-lee-prml/PeriodWave.
