LipDiffuser: Lip-to-Speech Generation with Conditional Diffusion Models
Julius Richter, Danilo de Oliveira, Tal Peer, Timo Gerkmann
TL;DR
LipDiffuser tackles lip-to-speech in scenarios where audio is missing or severely degraded by leveraging a conditional diffusion framework. It combines a magnitude-preserving diffusion model (MP-ADM) with magnitude-preserving FiLM conditioning (MP-FiLM) to fuse video-derived cues and speaker embeddings, producing mel-spectrograms that are then converted to waveform by a neural vocoder. The method, evaluated on LRS3 and the noisy LRS3-CHiME3 benchmark, achieves superior speech quality and speaker similarity among lip-to-speech baselines and remains competitive on ASR, with formal listening tests reinforcing perceptual gains. The work demonstrates the viability and robustness of diffusion-based lip-to-speech with alignment-friendly conditioning, and its results suggest strong potential for real-world media restoration and accessibility applications.
Abstract
We present LipDiffuser, a conditional diffusion model for lip-to-speech generation synthesizing natural and intelligible speech directly from silent video recordings. Our approach leverages the magnitude-preserving ablated diffusion model (MP-ADM) architecture as a denoiser model. To effectively condition the model, we incorporate visual features using magnitude-preserving feature-wise linear modulation (MP-FiLM) alongside speaker embeddings. A neural vocoder then reconstructs the speech waveform from the generated mel-spectrograms. Evaluations on LRS3 demonstrate that LipDiffuser outperforms existing lip-to-speech baselines in perceptual speech quality and speaker similarity, while remaining competitive in downstream automatic speech recognition. These findings are also supported by a formal listening experiment.
