🤖 AI Summary
Continuous-Time Consistency Distillation (CTCD) faces scalability challenges for large-scale image/video diffusion models due to prohibitive Jacobian-vector product (JVP) computational overhead and inadequate evaluation benchmarks. Method: This work pioneers the successful application of CTCD to 14B-parameter text-to-image/video generation, introducing the robust Consistency Model (rCM) framework. rCM employs score distillation as a long-horizon regularization term and incorporates backward divergence with pattern search to mitigate error accumulation in standard consistency models (sCM). We design an efficient JVP kernel leveraging FlashAttention-2 and integrate parallel computation optimizations. Results: On 5-second video generation, rCM achieves high-fidelity sampling in just 1–4 steps—accelerating inference by 15–50×—while matching DMD2’s FID and CLIP scores and significantly surpassing it in sample diversity.
📝 Abstract
This work represents the first effort to scale up continuous-time consistency distillation to general application-level image and video diffusion models. Although continuous-time consistency model (sCM) is theoretically principled and empirically powerful for accelerating academic-scale diffusion, its applicability to large-scale text-to-image and video tasks remains unclear due to infrastructure challenges in Jacobian-vector product (JVP) computation and the limitations of standard evaluation benchmarks. We first develop a parallelism-compatible FlashAttention-2 JVP kernel, enabling sCM training on models with over 10 billion parameters and high-dimensional video tasks. Our investigation reveals fundamental quality limitations of sCM in fine-detail generation, which we attribute to error accumulation and the"mode-covering"nature of its forward-divergence objective. To remedy this, we propose the score-regularized continuous-time consistency model (rCM), which incorporates score distillation as a long-skip regularizer. This integration complements sCM with the"mode-seeking"reverse divergence, effectively improving visual quality while maintaining high generation diversity. Validated on large-scale models (Cosmos-Predict2, Wan2.1) up to 14B parameters and 5-second videos, rCM matches or surpasses the state-of-the-art distillation method DMD2 on quality metrics while offering notable advantages in diversity, all without GAN tuning or extensive hyperparameter searches. The distilled models generate high-fidelity samples in only $1sim4$ steps, accelerating diffusion sampling by $15 imessim50 imes$. These results position rCM as a practical and theoretically grounded framework for advancing large-scale diffusion distillation.