xGen-VideoSyn-1: High-Fidelity Text-to-Video Synthesis with Compressed Representations

We present xGen-VideoSyn-1, a text-to-video (T2V) generation model capable of producing realistic scenes from textual descriptions. We extend the latent diffusion model (LDM) architecture by introducing a video variational autoencoder (VidVAE). Our Video VAE compresses video data spatially and temporally, significantly reducing the length of visual tokens and the computational demands associated with generating long-sequence videos. To further address the computational cost, we propose a divide-and-merge strategy that maintains temporal consistency across video segments. Our Diffusion Transformer (DiT) model incorporates spatial and temporal self-attention layers, enabling robust generalization across different time frames and aspect ratios. We also designed a data collection and processing pipeline, which helped us gather over 13 million high-quality video-text pairs. The pipeline includes steps such as clipping, text detection, motion estimation, aesthetics scoring, and dense captioning based on our xGen-MM video-language model. Training the Video VAE and DiT models required approximately 40 and 642 H100 days, respectively. Our model supports over 14-second 720p video generation in an end-to-end way and demonstrates competitive performance against state-of-the-art T2V models.