🌱 Seedance 2.0 Save Video

If you use this pack for more than a day, you will hit the wall this node exists to knock down: every video URL BytePlus hands you expires in about 24 hours. Render a clip, close ComfyUI, come back tomorrow, and the link is a corpse. Seedance 2.0 Save Video is the insurance: it downloads the mp4 from a video_url to your ComfyUI output folder, where it lives forever, and - if you want - decodes it into a ComfyUI IMAGE batch you can keep working with. The README's advice is unambiguous: "Use Save Video for anything you need to keep." This is the node that makes the pack usable instead of a very expensive screensaver.

The inputs

• video_url - the output of any generation node, Retrieve Task Result, Task History Browser, or Batch Result Browser.
• save_subfolder - subfolder under your output dir, default seedance2.
• filename_prefix - default seedance2; files save as <prefix>_00001.mp4, auto-incrementing.
• load_frames - default false. When on, the node decodes the saved video into an IMAGE batch. The tooltip is your friend: "Off is safer for 1080p/4k videos." Loading frames of a long 4K clip into RAM is exactly how you OOM a machine.
• frame_load_cap - when load_frames is on: 0 loads all frames, anything else caps the count. Default 1 - i.e., just the first frame for a cheap preview.
• skip_first_frames and select_every_nth - trim the start and thin the frame rate of the batch you decode.

Outputs

frames (IMAGE batch, meaningful only with load_frames on), filepath (the STRING path of the saved file), and frame_count (INT - number of frames decoded, or 0 with load_frames off).

How it works

It streams the URL to disk in chunks, auto-incrementing the filename so nothing is overwritten, then embeds ComfyUI workflow metadata into the mp4 (a genuinely nice touch - the metadata survives in the file). With load_frames on it decodes via OpenCV with your skip/cap/nth settings. If the URL is dead, you get an "Invalid URL" error in the node rather than a silent fail.

The workflow habit worth forming

Generator video_url → Save Video video_url

Wire it in before you queue the render, not after. The cost is one extra download while the task is fresh; the alternative is re-paying for a render you can't retrieve. And if you want frames to keep feeding into local ComfyUI processing - upscaling, frame interpolation, whatever you'd do to a local video - flip load_frames on with a frame_load_cap you can afford.

The honest tradeoff: Save Video is strictly more useful than Preview Video URL, but it's heavier - full download plus optional frame decode versus a quick glance. Use the preview node to decide, the saver to keep. This is the one node I'd call mandatory in any workflow where the output matters.

Install: ComfyUI Manager → Install via Git URL → https://github.com/nnnnkatsu/seedance2-comfyui-byteplus, restart. Frame loading needs OpenCV, which the pack's requirements.txt installs.