MultiTrack Info Output

Most video workflows in ComfyUI start with a fixed resolution stuffed into a latent node, and then you swap the model format and everything silently breaks. MultiTrack Info Output exists to kill that class of bug. Give it the TRACKS_INFO coming out of a MultiTrack editor and it hands back the dimensions, duration, frame rate, and task count as plain numbers you can wire straight into Empty Latent, conditioning, or any node that needs them.

The five numbers

• WIDTH / HEIGHT - the timeline's resolution (INT).
• TOTAL_FRAMES - the full duration in frames (INT).
• FPS - the timeline's frame rate (FLOAT).
• TASK_COUNT - how many task segments are on the task track (INT).

That last one is the sleeper. Because workflows are meant to loop once per task segment, TASK_COUNT is what you feed a repeat-while or loop node so your graph processes every segment of the timeline automatically. Change the timeline and the loop count updates with it - no manual renumbering.

Why you'd bother

The node is trivial on its face - one input, five outputs - but it's the connective tissue that makes the MultiTrack editor useful as a driver rather than a fancy preview. A typical t2v/i2v pipeline reads: MultiTrack editor → this node (dimensions + fps + task count) → Task Output (prompts for a segment) → model conditioning → generate → next segment. When you switch the editor's format from Wan to MiniMax H3 and the resolution changes, every downstream node that reads these outputs follows along. The alternative - hardcoding 1280×720 in three different nodes - is how you get a half-cropped video at 2am.

Install and use

It ships in ComfyUI-Easy-Media, so the install is the pack install:

cd ComfyUI/custom_nodes
git clone https://github.com/yolain/ComfyUI-Easy-Media.git

then restart ComfyUI (or use ComfyUI Manager and search "Easy-Media"). Make sure FFmpeg is installed on your system - the README flags it as a hard prerequisite for the whole pack, and video nodes rely on it.

The one gotcha

TRACKS_INFO is a custom type - there's no sensible way to build it by hand, so this node is meaningless until you connect it to a real MultiTrack editor upstream. That's by design. If you see zeroes or None where you expect numbers, check the editor's format field (some formats report a default frame rate until you add a video/task segment) rather than suspecting the info node itself. It's a reader, not a calculator: garbage timeline in, garbage numbers out.