OmniFusion: Simultaneous Multilingual Multimodal Translations via Modular Fusion

TL;DR

OmniFusion is an end-to-end multimodal translation model that combines pretrained multimodal foundation models with translation LLMs, enabling simultaneous multilingual multimodal translation with reduced latency and improved quality.

Contribution

It introduces a novel fusion strategy connecting multimodal foundation models with translation LLMs for end-to-end training in multilingual multimodal translation.

Findings

Reduces 1-second latency in simultaneous speech translation.

Effectively leverages audio and visual inputs for translation.

Improves overall translation quality.

Abstract

There has been significant progress in open-source text-only translation large language models (LLMs) with better language coverage and quality. However, these models can be only used in cascaded pipelines for speech translation (ST), performing automatic speech recognition first followed by translation. This introduces additional latency, which is particularly critical in simultaneous ST (SimulST), and prevents the model from exploiting multimodal context, such as images, which can aid disambiguation. Pretrained multimodal foundation models (MMFMs) already possess strong perception and reasoning capabilities across multiple modalities, but generally lack the multilingual coverage and specialized translation performance of dedicated translation LLMs. To build an effective multimodal translation system, we propose an end-to-end approach that fuses MMFMs with translation LLMs. We introduce a novel fusion strategy that connects hidden states from multiple layers of a pretrained MMFM to a translation LLM, enabling joint end-to-end training. The resulting model, OmniFusion, built on Omni 2.5-7B as the MMFM and SeedX PPO-7B as the translation LLM, can perform speech-to-text, speech-and-image-to-text, and text-and-image-to-text translation. Experiments demonstrate that OmniFusion effectively leverages both audio and visual inputs, achieves a 1-second latency reduction in SimulST compared to cascaded pipelines and also improves the overall translation quality\footnote{Code is available at https://github.com/saikoneru/OmniFusion}.