SyncVid: World-Equivariant Diffusion for Synchronized Video Generation
Organizations: Qualcomm AI Research is an initiative of Qualcomm Technologies, Inc.
Abstract
Generating multiple videos of a dynamic scene from a single reference video requires synthesizing both observed and unobserved content consistently across viewpoints. Existing camera-control methods for video diffusion typically rely on architectural mechanisms, including camera embeddings, cross-view attention, and geometric conditioning. Although effective for static scene content, these approaches often struggle with the fine-grained, dynamic geometry that must remain coherent across views and over time. We synchronize the diffusion process itself by sampling the Gaussian noise prior in a canonical 3D space derived from the source video and rasterizing it into target cameras, rather than sampling independently in each 2D image plane. Our method, SyncVid, lifts a monocular video into a canonical 4D representation, associates noise with scene geometry and unseen space, and rasterizes the resulting structured noise into arbitrary views. Because rendering can introduce local correlations, we further propose a cross-view-consistent whitening procedure that decorrelates neighboring pixels while preserving correspondence across views. The structured noise serves as the diffusion prior for a LoRA-adapted pretrained video diffusion model, requiring no architectural modifications. By enforcing spatiotemporal and cross-view coherence at the source of stochasticity, SyncVid generates synchronized videos and improves both perceptual quality and cross-view consistency in our experiments. Project page: https://qualcomm-ai-research.github.io/SyncVid-Webpage.
Figures & tables
| View Synchronization | Temporal Consistency | Camera Accuracy | ||||||
| Method | Generation Length | Mat. Pix. | FVD-V | CLIP-V | CLIP-F | RotErr | TransErr | |
| Dynamic | Static | |||||||
| DaS [ 22 ] | 49 | 494 | 1251 | 315.69 | 86.01 | 97.40 | 0.1549 | 0.2164 |
| Go-with-the-Flow [ 11 ] | 49 | 687 | 1277 | 296.30 | 87.44 | 96.78 | 0.1225 | 0.1109 |
| ReCamMaster [ 4 ] | 75 | 1073 | 1428 | 233.70 | 88.06 | 97.39 | 0.1665 | 0.1778 |
| ArtiFixer-14B [ 14 ] | 75 | 1128 | 1937 | 195.55 | 88.99 | 97.55 | 0.0780 | 0.0529 |
| Variant | View Synchronization | Temporal Consistency | |||
|---|---|---|---|---|---|
| Mat. Pix. | FVD-V | CLIP-V | CLIP-F | ||
| Noise | standard | 222 | 518.77 | 88.76 | 97.34 |
| w/o whitening | 208 | 468.39 | 88.53 | 96.92 | |
| w/ whitening | 267 | 461.44 | 91.05 | 97.61 | |
| Conditioning | +none (I2V) | 224 | 830.00 | 87.53 | 97.80 |
| +render view | 231 | 574.50 | 89.34 | 97.59 | |
Appendix figures & tables9 assets
Supplementary material from the paper’s appendix.
Appendix
| Field | Range | Requirement or meaning |
| Gates (all must be true) | ||
| is_single_continuous_shot | bool | No cuts or transitions. |
| is_real_time_playback | bool | No time-lapse, hyper-lapse, or slow motion. |
| is_physically_plausible | bool | No VFX blends, text overlays, or screen-in-screen. |
| is_motion_blur_acceptable | bool | No motion blur severe enough to destroy structure. |
| is_focal_blur_acceptable | bool | Not excessively out of focus. |
| # | Stage | Surviving | Removed |
| Stage-1 judgements available | 7,561 | ||
| 1 | Gate pass (all six gates true) | 6,617 | 944 gate failures |
| 2 | Landscape (width height) | 5,973 | 644 portrait or square |
| 3 | De-duplication (unique clips) | 4,541 | 1,432 copies of 1,197 clips |
| 4 | Moving camera body | 2,231 | 2,310 static-source |
| 5 | Optical-effect removal | 2,227 | 4 optical-effect |
| Standard | Complex | |
| Composition bucket | simple | complex |
| Candidates in pool | 404 | 1,823 |
| Selection | top 100 by | balance to 1,000, then top 100 by |
| range | 24.0–64.0 | 64.0–100.0 |
| mean | 30.9 | 71.2 |
| median | 32.0 | 64.0 |
| 4D representation (NoPo4D) | Noise rasterization | Whitening | Video generation (WAN2.2-14B) | |||
|---|---|---|---|---|---|---|
| DiT | VAE decoder | Total | ||||
| Compute time (sec.) | 4.18 | 6.44 | 0.53 | 23.97 / step | 4.60 | 1203.1 |
Multi-View Video Generation
Multi-view video generation creates synchronized, viewpoint-consistent videos for controllable scene synthesis, reconstruction, and simulation.
See all 57 papers