AV-DiT: Taming Image Diffusion Transformers for Efficient Joint Audio and Video Generation

Recent Diffusion Transformers (DiTs) have shown impressive capabilities in generating single-modality content, including images, videos, and audio. However, the potential of DiTs to enable superb multimodal content creation remains underexplored. To bridge this gap, we introduce AV-DiT, a novel and efficient audio-visual diffusion transformer designed to generate high-quality, realistic videos with synchronized audio tracks. To minimize model complexity and computational costs, our AV-DiT utilizes a modality-shared DiT backbone pre-trained on image-only data, with only newly inserted adapters being trainable. This shared backbone facilitates the generation of both audio and video. Specifically, the video branch incorporates a trainable temporal attention layer into a pre-trained DiT block for capturing the temporal consistency for video generation. In addition, a small number of trainable parameters adapt the image-based DiT block to learn the acoustic characteristics for audio generation. An extra shared self-attention block reused from the DiT block, equipped with lightweight parameters, facilitates feature interaction between audio and visual modalities for alignment. Extensive experiments on the datasets demonstrate that our AV-DiT achieves state-of-the-art performance in joint audio-visual generation with significantly fewer tunable parameters. Furthermore, our results highlight that a single shared image generative backbone with modality-specific adaptations is sufficient for constructing a joint audio-video generator.