Sonder Save Video

Sonder Save Video is the node your generation actually lands in when you're using Sonder Editor - the output half of the loop. It takes your rendered IMAGE tensor, encodes it to a project video asset in the project's exports folder, optionally muxes audio, shows a thumbnail of the first frame on the node card, and - here's the part no stock save node does - it can auto-correct accumulated VAE color drift against the render's protected context frames.

That color-drift correction is worth pausing on, because it's the feature that sounds like marketing and isn't. Anyone who's chained video segments through a VAE knows the enemy: each decode drifts a little, and by segment five your colors have walked off. Sonder's trick is that the render window carries untouched context frames from the editor - frames that weren't denoised. This node fits a correction that matches those clean frames back to the editor's pre-encode reference, applies it per save, and records the outcome in the asset metadata. It's on by default, and it auto-skips when there's no context or the correction would exceed safe bounds, so a bad fit can't wreck a good render.

Inputs and outputs that matter

Core inputs: project (saves to its exports folder), frames (the IMAGE batch), filename_prefix, fps, and mode - Video (plain save) or Take (saves and auto-places the result back on the timeline as a new lane, which is the iteration loop closing). The place_audio_on_timeline toggle exists so fixed, already-placed audio doesn't spawn a duplicate lane per take - turn it off for unchanging audio.

The save_preset dropdown is the other thing to know: Compatible MP4 (browser-safe, BT.709 tagged) for everyday work, High Quality MP4, Editing Master MP4 (4:4:4, your browser may not play it), ProRes 422 HQ for handoff to an editor, Lossless FFV1 (RGB) for archival, and Custom for expert control of codec/container/CRF/pixel format/PNG-sequence output. embed_metadata (default on) bakes the full ComfyUI workflow into the file - turn it off before sharing if your graph is private. Optional audio muxes sound in. Output: output_path.

Install and gotchas

Pack install (ComfyUI Manager search Sonder Editor, or git clone + pip install -r requirements.txt + restart), and a working ffmpeg - the bundled imageio-ffmpeg binary is a fallback, but a system ffmpeg on PATH handles the wider preset range, and the ProRes/FFV1 presets especially want it.

The failure to plan for: if ffmpeg not found errors show up on save, that's the first thing to check. And remember the security note from the README - with embed_metadata on, exported files carry your prompts, model names, and paths. The "Compatible MP4" preset is the one that plays everywhere; if a video you saved won't preview, check whether you picked an Editing Master or ProRes preset and re-save in a browser-safe format. It's the node that makes "generate, place, review, regenerate" feel like a loop instead of a chore.