FL ProRes Video

If your AI video is going into a real edit - Premiere, Resolve, Final Cut - an MP4 is the wrong master. It's compressed, it's 8-bit, it has no alpha, and it degrades the moment you start color-grading it. FL_ProResVideo exports your frame batch as ProRes 4444, the format editors actually want: 10-bit, near-lossless, and it carries an alpha channel. This is the node you use when the output isn't the final deliverable, it's the source clip for the next stage of post.

ProRes 4444 is an editing codec, not a delivery one. The "4444" means full color plus an alpha channel, and it's built to survive being re-encoded and graded over and over without visibly falling apart. The tradeoff is size: these files are big, sometimes an order of magnitude larger than the equivalent MP4. That's the deal you're making - fidelity and edit-friendliness in exchange for disk space. For a master that's exactly the right deal.

The inputs and output

• images (IMAGE) - the frame batch to encode.
• fps (1–120, default 30) - frame rate of the output. Match this to your source; if you generated at 16fps and interpolated up, set the number that gives the right playback speed.
• filename (default prores_output) - the output file name.
• save_directory - where to write it. Leave it blank to use the default output location; set an absolute path to drop it somewhere specific (handy on a remote box where you're syncing a particular folder).

Output is a STRING - the path to the file it wrote - so you can chain it into something that acts on the finished video.

Installing it

It's part of ComfyUI_Fill-Nodes. ComfyUI Manager: search Fill-Nodes, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/filliptm/ComfyUI_Fill-Nodes

then restart ComfyUI.

The dependency that matters: ProRes encoding runs through FFmpeg. The node shells out to it, so you need a working FFmpeg on the machine (with ProRes support, which the standard builds have). On a normal ComfyUI desktop install this is usually already present or trivially installable; on a bare cloud box, ffmpeg may not be there and you'll get an encode error until you install it. That's the single most common reason this node fails.

Worth knowing

Two things beyond FFmpeg. First, the files are large - don't be surprised when a few seconds of 1080p ProRes is hundreds of megabytes; that's normal, it's a master format. If you just want something to post, this is the wrong node - use a WebM/MP4 saver for delivery and keep ProRes for the edit. Second, the alpha only means something if your frames actually have transparency; a fully opaque render exports fine, it just won't have a useful matte to key against in your editor. Set the fps to match your real timeline, point save_directory at the folder your NLE watches, and this becomes the clean handoff from "generated in ComfyUI" to "finished in post."