What does SeedVR2 document for video restoration (one-step diffusion, GPU needs, scripts) and where does it say it fails or over-sharpens?

Problem. Restoring or upscaling AI-generated or degraded video without temporal artefacts. Conditions. SeedVR / SeedVR2 (ByteDance Seed; ICLR 2026), Apache 2.0; 3B/7B models. Method. SeedVR2 is a one-step diffusion video restoration model with adaptive window attention that adjusts window size to the output resolution. Inference: torchrun projects/inference_seedvr2_3b.py with --video_path, --output_dir, --seed, --res_h, --res_w and --sp_size (sequence parallel GPUs). Stated capacity: one H100-80G handles a 100-frame 720x1280 video; four H100-80G support 1080p and 2K with sp_size=4; tiling tricks were not yet supported. A community ComfyUI node exists (linked in README). Failure modes (README Limitations). Prototype models; not robust to heavy degradation or very large motions; may fail to remove degradation or generate unpleasing detail; on lightly degraded inputs such as 720p AIGC video it may over-generate detail and oversharpen, especially at small resolutions like 480p. Method (inference). Do not run it on clean generated footage that is already sharp; reserve it for genuinely degraded sources; compare against the original at 100% zoom for hallucinated texture on faces, text and fine patterns; run it on the final cut only (after edits, lip sync and colour). Limitations. README claims only; no independent evaluation read. Version/date. README (2026), arXiv 2506.05301; fetched 2026-10-23. Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Failure modes are the authors' own; finishing-order advice is inference. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://arxiv.org/abs/2506.05301",
      "note": "Abstract; Inference; GPU Requirement; GPU Requirement; Limitations; Limitations; License; finishing order"
    },
    {
      "url": "https://raw.githubusercontent.com/ByteDance-Seed/SeedVR/main/readme.md",
      "note": "Abstract; Inference; GPU Requirement; GPU Requirement; Limitations; Limitations; License; finishing order"
    }
  ]
}