FoleyCrafter: Bring Silent Videos to Life with Lifelike and Synchronized Sounds (2407.01494v1)

Abstract: We study Neural Foley, the automatic generation of high-quality sound effects synchronizing with videos, enabling an immersive audio-visual experience. Despite its wide range of applications, existing approaches encounter limitations when it comes to simultaneously synthesizing high-quality and video-aligned (i.e.,, semantic relevant and temporal synchronized) sounds. To overcome these limitations, we propose FoleyCrafter, a novel framework that leverages a pre-trained text-to-audio model to ensure high-quality audio generation. FoleyCrafter comprises two key components: the semantic adapter for semantic alignment and the temporal controller for precise audio-video synchronization. The semantic adapter utilizes parallel cross-attention layers to condition audio generation on video features, producing realistic sound effects that are semantically relevant to the visual content. Meanwhile, the temporal controller incorporates an onset detector and a timestampbased adapter to achieve precise audio-video alignment. One notable advantage of FoleyCrafter is its compatibility with text prompts, enabling the use of text descriptions to achieve controllable and diverse video-to-audio generation according to user intents. We conduct extensive quantitative and qualitative experiments on standard benchmarks to verify the effectiveness of FoleyCrafter. Models and codes are available at https://github.com/open-mmlab/FoleyCrafter.

FoleyCrafter: Bring Silent Videos to Life with Lifelike and Synchronized Sounds

The paper "FoleyCrafter" presents a novel framework addressing the important problem of automatic Foley generation, focusing on creating lifelike and synchronized sound effects for silent videos. This research tackles existing challenges of achieving high-quality, semantically relevant, and temporally synchronized audio, leveraging advancements in neural models and high-quality large-scale datasets.

Semantic and Temporal Alignment in Foley Generation

FoleyCrafter builds upon state-of-the-art text-to-audio (T2A) models to ensure high-quality audio synthesis while introducing specific modules to integrate and align with visual content. The system comprises:

1. Semantic Adapter: This module enhances semantic alignment by integrating visual features directly into the audio generation process. The visual encoder extracts features from video frames employing the CLIP model, while parallel cross-attention layers condition the T2A model on these video features. This novel approach effectively maintains the T2A model's performance while mapping visual inputs to appropriate audio outputs without a reliance on external text.
2. Temporal Controller: To achieve precise temporal synchronization, this component incorporates a timestamp detector to predict sound events and a timestamp-based adapter to fine-tune the alignment of generated audio with visual content. The timestamp detector processes video data to identify sound and silent intervals, employing these predictions to guide the generation process within the UNet architecture of the T2A model.

Experimental Evaluation

The paper presents an extensive set of experiments validating the efficacy of FoleyCrafter across various metrics and benchmarks. When evaluated on the VGGSound and AVSync15 datasets, FoleyCrafter demonstrates superior performance compared to existing techniques like SpecVQGAN and Diff-Foley, achieving state-of-the-art results on measures such as Mean KL Divergence (MKL), CLIP similarity, and Frechet Distance (FID). Specifically, it achieves significantly better scores indicating both high-fidelity and closely aligned audio-visual pairs.

In terms of temporal synchronization, FoleyCrafter shows marked improvement in onset detection accuracy (Onset ACC) and average precision (Onset AP), underscoring the effectiveness of the temporal controller. The qualitative analyses further showcase the framework’s ability to generate coherent and well-synchronized audio, which is a critical advancement for applications requiring precise audiovisual synchrony.

Implications and Future Directions

The implications of FoleyCrafter are significant for various domains including film post-production, immersive gaming, and automated content creation. By providing a reliable and flexible tool for Foley generation, it reduces dependence on manual processes, thus saving time and resources while enhancing the overall audiovisual experience.

From a theoretical standpoint, FoleyCrafter exemplifies the effective integration of multimodal inputs to enhance generative models, paving the way for future research in more complex synchronization tasks across other modalities. The use of parallel cross-attention layers could be explored further in broader contexts, potentially improving generalization for other text, audio, and visual integration tasks.

Limitations and Ethical Considerations

The primary limitations identified include the dependency on the timestamp detector's accuracy for effective temporal synchronization and the requirement of strong, high-quality datasets for optimal performance. The broader impact of such technology also necessitates ethical considerations concerning the misuse of generated audio for deceptive purposes, calling for responsible use and stringent guidelines.

Conclusion

FoleyCrafter represents a significant advancement in the field of automated Foley generation, integrating sophisticated methods for semantic and temporal alignment to produce high-quality, synchronized audio for silent videos. Its robust framework, validated by extensive experimentation, not only achieves superior performance compared to existing methods but also provides new avenues for research and practical applications in audiovisual content creation.