ComfyUI-RotoTools

ComfyUI-RotoTools

Small, focused nodes for roto / alpha-matte workflows in ComfyUI (built around LTX alpha-gen, but they work with any IMAGE batch).

Nodes

Save Image Sequence (TGA, RGBA) — image/save

Saves an IMAGE batch as numbered TGA frames, keeping a real alpha channel when the batch is RGBA (feed it from Join Image with Alpha).

• One zip instead of thousands of loose files (save_as_zip, on by default).
• Zip named after the source video: connect the Load Video node to source_video and clip.mp4 becomes clip.zip. Without it, filename_prefix is used.
• One folder for every zip: type or paste output_folder once; every run drops its zip there.
• Never overwrites an earlier result unless you turn overwrite on (_v2, _v3 ...). If the old zip is open in Explorer / 7-Zip, the new one is saved under a new name instead of failing.
• Zip is written to *.zip.part and renamed when complete, so a crash never leaves a half-written zip that looks finished.
• Lossless RLE compression option, start number, zero padding, and a transparent preview of a few frames on the node.
• Optional zip_name input: an exact zip name from another node (wins over source_video).
• Turn save_as_zip off to get loose .tga files.

Spec Readout (size / frames / fps) — image/monitor

Drop it at any stage of a workflow to see W x H | frames | fps | seconds printed on the node itself while the graph runs. Optional padding check (width/height multiple of 32, frames = 8n+1) and an optional compare_to input that shows MATCHES / MISMATCH against another batch (for example the original clip).

Load Video Batch (Folders) — image/video

Built for hundreds of clips in one go. Give it one or more folders; every video in their sub-folders is found automatically (natural sort, so shot2 comes before shot10) and one video per run is sent on as a VIDEO.

batch_folder  = x\ep93, x\ep94          output_folder = D:\rotos
x\ep93\shot1\shot1.mp4   ->  D:\rotos\ep93\shot1.zip
x\ep94\shot1\shot1.mp4   ->  D:\rotos\ep94\shot1.zip
y\ep93\shot1\shot1.mp4   ->  D:\rotos\ep93 (y)\shot1.zip   (another folder named ep93)

Adding folders (any mix of drives):

• + Add folders… on the preview opens the normal Windows folder dialog (macOS / Linux: the system one). Ctrl / Shift click to pick several. Open it again to add more from another drive; folders already in the list are not added twice.
• ✕ remove on a folder's header takes it out of the batch; Clear empties the list (nothing is deleted on disk).
• Or type / paste into batch_folder: one folder per line or comma separated. Explorer's Copy as path (select the folders, Ctrl+Shift+C) can be pasted as is.
• The dialog opens on the computer running ComfyUI. Dragging folders onto the node is not possible: browsers never give a web page the full path of a dropped folder.

Single videos (no folder needed), mixed freely with folders:

• Drop video files onto the node. Like the normal Load Video, each dropped video is copied once into ComfyUI\input\rototools_drops and that copy is used. The same video dropped again reuses its copy.
• Or list video files in batch_folder like folders (no copy is made).
• Their zips go straight into the save folder: SAVE FOLDER\clip_a.zip. Two videos with the same name from different places become clip_a and clip_a (misc) (misc = the folder the second one sits in), and each keeps its zip name from run to run.
• The big ✕ in the middle of a single video's tile (hover) takes it out of the batch; ✕ remove all on the Single videos header removes them all.

batch_folder  = D:\clips\clip_a.mp4          output_folder = D:\rotos
                x\ep93
D:\clips\clip_a.mp4      ->  D:\rotos\clip_a.zip
x\ep93\shot1\shot1.mp4   ->  D:\rotos\ep93\shot1.zip

1. Replace Load Video with this node and connect video where Load Video went.
2. Connect zip_name to the saver's zip_name input and zip_folder to the saver's output_folder. Each input folder gets its own folder inside output_folder, named after it; zips are named after the video file. Another input folder with the same name gets its location added: y\ep93 becomes ep93 (y). Each output folder remembers its input folder (a hidden .rototools_source file), so a folder keeps the same output folder from run to run, whether it is batched with the other ep93 or on its own. The preview shows the full path of each. Two videos with the same name inside one folder become take, take_2.
3. Set Run's batch count to the number "to do" on the preview bar (more is fine: extra runs are skipped in a moment). With skip_if_zip_exists on (default), every run takes the next video that has no zip yet, so a cancelled queue, a crash or a restart never skips videos: just press Run again. A slim "Last run: n / total …" line shows where the batch is.
4. A video whose run left no zip (failed or cancelled) is tried once more; after a second try it is passed over until ComfyUI restarts or you press Clear, so one broken video cannot use up the queue. Every decision is printed as [LoadVideoBatchFolders] … in ComfyUI's console.
5. Leave shots out: the big ✕ in the middle of a tile (hover) greys it out and it is not queued; ↺ undo puts it back. This is saved with the workflow. Clear empties the node completely (list, left-out shots, last-run line).
6. index only matters with skip_if_zip_exists off: then the video at index is processed even if its zip exists (to redo one).

Preview grid: the node shows a thumbnail of every detected video, grouped per input folder (with its full path and output folder). Hover a tile to play it, click it for a full view in the node (✕ to go back to the grid). Resize the node or use the slider to change the tile size. ✓ = zip already exists; the yellow frame is the video of the last run. Videos the browser cannot play (some .mov/.mkv/.avi codecs) still get a thumbnail.

Outputs: video, zip_name, video_path, index, total, zip_folder, shot_label (where the shot comes from + its zip name, e.g. ep93 / shot6 or single / shot6: unique even for same-named shots; connect it to Roto Review's name).

Roto Review (A/B) — image/video

A preview-only review player for checking roto work, based on ComfyUI-KM-VideoReview by Kasun Malinda (MIT). Connect the original frames to images_a and the RGBA roto frames to images_b (optionally Load Video Batch's shot_label to name, so same-named shots from different folders stay apart in the history and downloads). Nothing is written to ComfyUI's output folder: preview frames live in the temp folder.

• Everything of the original player: wipe (drag the line), side by side, difference, A/B flip, frame stepping and scrubbing, loop / bounce, fullscreen, exposure / gamma.
• B shows the roto over a background of your choice (red, green, blue, black, white, grey, checkerboard), as the alpha matte, or as is.
• Light preview by default (¼ resolution, low jpeg/webp quality): it is only for looking; the TGA zip is the full-quality master. Raise Playback resolution / quality on the node if you want a sharper preview.
• Layout: the video fits exactly at the node's width (no black bars); the rest of the node's height is the history. The node keeps the size you give it.
• History: every shot reviewed in this ComfyUI session as a grid of thumbnails with a count (scrolls when full); click one to review it again. Only if the drive gets low (under 10 GB free) are the oldest dropped. ComfyUI empties the temp folder on restart, so the strip starts fresh then.
• ⤓ Alpha matte: downloads the shot's matte (white = subject on black, mp4) at full resolution, made from lossless full-size alpha frames, whatever the preview settings. Saved by your browser; nothing goes to ComfyUI's output folder. The background colour is only for viewing in the player.

Install

Comfy Registry / ComfyUI-Manager (once published): search for RotoTools in ComfyUI-Manager, or run comfy node install rototools.

Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/dipto8103/ComfyUI-RotoTools

Restart ComfyUI. No extra dependencies (uses Pillow and NumPy, which ComfyUI already ships).

Notes on alpha

TGA stores straight (non-premultiplied) alpha. Make sure the alpha you feed into Join Image with Alpha has the direction your matte uses (ComfyUI's node treats its input as an inverted mask, so pass an inverted mask if your matte is white = subject).

Development

pip install -r requirements-dev.txt
pytest

The tests stub folder_paths, so ComfyUI itself is not needed.

Versions

Semantic Versioning. See CHANGELOG.md; maintainers see RELEASING.md.

License

MIT, see LICENSE.

The Roto Review player (review.py, web/js/roto_review*.js) is based on ComfyUI-KM-VideoReview, Copyright (c) 2026 Kasun Malinda, MIT License; its notice is kept in those files and in LICENSE-KM-VideoReview.