🤖 AI Summary
This work addresses the challenges of computational scalability, temporal coherence, and narrative semantic understanding in automatic music generation for long videos. The authors propose a hierarchical generation framework that leverages emotion as a dense representation of narrative logic. Specifically, a frozen vision-language model serves as a continuous emotion sensor to extract valence-arousal trajectories. A dual-branch injection mechanism is introduced: global semantic anchors govern overall musical style, while token-level emotion adapters modulate local dynamics. This approach enables, for the first time, end-to-end, fully automatic music generation for long-form videos with minimal additional computational overhead. Experimental results demonstrate state-of-the-art performance in both musical consistency and narrative alignment.
📝 Abstract
Synthesizing coherent soundtracks for long-form videos remains a formidable challenge, currently stalled by three critical impediments: computational scalability, temporal coherence, and, most critically, a pervasive semantic blindness to evolving narrative logic. To bridge these gaps, we propose NarraScore, a hierarchical framework predicated on the core insight that emotion serves as a high-density compression of narrative logic. Uniquely, we repurpose frozen Vision-Language Models (VLMs) as continuous affective sensors, distilling high-dimensional visual streams into dense, narrative-aware Valence-Arousal trajectories. Mechanistically, NarraScore employs a Dual-Branch Injection strategy to reconcile global structure with local dynamism: a \textit{Global Semantic Anchor} ensures stylistic stability, while a surgical \textit{Token-Level Affective Adapter} modulates local tension via direct element-wise residual injection. This minimalist design bypasses the bottlenecks of dense attention and architectural cloning, effectively mitigating the overfitting risks associated with data scarcity. Experiments demonstrate that NarraScore achieves state-of-the-art consistency and narrative alignment with negligible computational overhead, establishing a fully autonomous paradigm for long-video soundtrack generation.