Ovi: Twin Backbone Cross-Modal Fusion for Audio-Video Generation (Sep 2025)

Title: Ovi: Twin Backbone Cross-Modal Fusion for Audio-Video Generation (Sep 2025)
Link: http://arxiv.org/abs/2510.01284v1
Date: September 2025

Summary:
OVI introduces a unified, one-pass audio-video generation paradigm using twin-DiT modules with blockwise cross-modal fusion, eliminating the need for separate pipelines or post-hoc alignment. The model trains identical video and audio towers, initialized with a strong pretrained video model architecture, from scratch on vast audio and video data. Fusion is achieved through blockwise exchange of timing via scaled-ROPE embeddings and semantics via bidirectional cross-attention. OVI generates realistic sound effects and speech, enabling cinematic storytelling with natural synchronization and context-matched audio.

Key Topics:
Audio-Video Generation
Cross-Modal Fusion
Diffusion Transformers (DiT)
Generative Models
Temporal Synchronization
Rotary Positional Embeddings (RoPE)
Speech Synthesis
Sound Effects Generation

Chapters:
00:00 - Introducing OVI Research
00:40 - OVI's Core Unified Approach
02:05 - Challenges in AV Generation
03:10 - OVI's Five Key Contributions
04:11 - Symmetric Twin Backbone
05:27 - Unified Prompt Input
06:19 - Achieving Temporal Alignment
07:32 - Data Pipeline Overview
08:09 - Strict Data Synchronization
09:18 - Detailed Multimodal Captions
09:58 - Two-Stage Training Strategy
11:38 - Weighted Loss Function
12:28 - Performance & Human Evaluation
14:04 - Prompt Effectiveness & Visual Proof
15:23 - OVI Limitations & Future Work
16:48 - Impact & Real-time Potential

Stock video credits:
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