Export With Ffmpeg (mtb)

Read the node's own description before you wire anything up: "Quite crude node, VHS is recommended now." That's melMass, the pack's author, telling you not to reach for this one first. VHS is VideoHelperSuite, and its VHS_VideoCombine node has been the community standard for turning an image batch into a video for a couple of years now - better codec support, live previews, audio muxing, the works. So why does this page exist? Because Export With Ffmpeg still ships in the pack, still shows up in older workflows, and if you've got one open you should know what it's doing.

What it actually does

It's a thin wrapper: hand it a batch of frames (or a playlist), and it shells out to ffmpeg to encode them into a video file at the frame rate you set. No preview, no fancy options - just "here are pixels, go make a video." That's the "crude" part. It gets the job done for a quick export but doesn't give you the flexibility VHS does around pixel formats, metadata, or audio tracks.

Inputs and outputs that matter

• fps (default 24) - playback frame rate for the output.
• prefix (default "export") - the filename prefix for what gets written.
• format - the container: mov, mp4, mkv, gif, or avi.
• codec - prores_ks (a ProRes intermediate, high quality, big files, pairs naturally with .mov), libx264 or libx265 (the standard H.264/H.265 you'd use for .mp4/.mkv), or gif.
• Optionally you feed it images (an IMAGE batch) or a playlist (a PLAYLIST - a pre-built list rather than a raw batch).

It outputs a single VIDEO, and it's flagged as an output node, so it writes the file as a side effect of running rather than just handing you a value to pipe further downstream.

Installing it

Get the whole MTB Nodes pack - there's no way to grab just this one node.

• ComfyUI Manager - search "MTB Nodes" (or "comfy_mtb"), install, restart.
• Manual - cd ComfyUI/custom_nodes && git clone https://github.com/melMass/comfy_mtb, then restart ComfyUI. If you cloned by hand instead of through Manager, run pip install -r requirements.txt inside the comfy_mtb folder first.

Because it shells out to ffmpeg, ffmpeg itself needs to be reachable on your system - either on PATH or bundled via a Python package the node relies on. If your ComfyUI install already runs other video nodes fine, you're set; if this is your first video-adjacent node, that's the first thing to check.

Common issues & troubleshooting

The node doesn't even load. comfy_mtb loads dozens of nodes at once, and it's normal for a handful to fail depending on your platform and what optional dependencies are present - the startup log prints something like "[comfy_mtb] STATUS -> Some nodes (N) could not be loaded" with a pointer to http://127.0.0.1:8188/mtb (your own ComfyUI address) for the specifics. Check that page before assuming your install is broken.

Output is corrupt or won't play. Mismatched codec/container pairs are the usual cause - prores_ks really wants a .mov, and a media player choking on a .mkv with an unusual codec inside isn't unusual. Try VLC before concluding the export itself failed.

It just feels limited. That's not a bug, it's the whole point of the author's own warning. If you need audio tracks, batch metadata, live preview while encoding, or more codec control, that's exactly the gap VHS was built to fill. Keep this node for quick one-off exports on old workflows; reach for VHS_VideoCombine for anything you're building fresh.