🤖 AI Summary
Existing video-to-audio (V2A) methods suffer from poor temporal coherence and weak semantic alignment in generating audio for long videos (>10 seconds), particularly due to the limited capacity of UNet-based diffusion models to capture long-range cross-modal dependencies. This work formally defines and addresses, for the first time, the task of generating semantically aligned audio from long videos. We propose LoVA—a novel diffusion-based model built upon the Diffusion Transformer (DiT) architecture—integrating cross-modal conditional diffusion with long-sequence spatiotemporal feature encoding to fundamentally enhance long-horizon modeling and audio-video semantic consistency. Experiments demonstrate that LoVA matches state-of-the-art performance on the 10-second benchmark while consistently outperforming all baselines on longer-video benchmarks, achieving significant improvements in both objective metrics (e.g., FAD, KL divergence) and subjective evaluation scores.
📝 Abstract
Video-to-audio (V2A) generation is important for video editing and post-processing, enabling the creation of semantics-aligned audio for silent video. However, most existing methods focus on generating short-form audio for short video segment (less than 10 seconds), while giving little attention to the scenario of long-form video inputs. For current UNet-based diffusion V2A models, an inevitable problem when handling long-form audio generation is the inconsistencies within the final concatenated audio. In this paper, we first highlight the importance of long-form V2A problem. Besides, we propose LoVA, a novel model for Long-form Video-to-Audio generation. Based on the Diffusion Transformer (DiT) architecture, LoVA proves to be more effective at generating long-form audio compared to existing autoregressive models and UNet-based diffusion models. Extensive objective and subjective experiments demonstrate that LoVA achieves comparable performance on 10-second V2A benchmark and outperforms all other baselines on a benchmark with long-form video input.