IAMCCS Cine Shotboard Tail Trim Policy

This is a small utility with a thankless job, and you'll only miss it when it's gone. IAMCCS Cine Shotboard Tail Trim Policy exists because of a quirk of LTX-style video models: frame counts get rounded up to an 8n+1 length, which pads your clip with a few extra frames at the tail. The Shotboard backend generates to the padded length and then needs to know how many of those frames to trim off so your final video matches the duration you actually asked for. This node is the memo that says "trim this many."

It doesn't generate anything, it doesn't touch a latent. It takes the cine_linx from your planner, attaches the trim policy to its metadata, and hands the same cine_linx back out. Downstream nodes (the duration-crop step, the V4 backend) read that metadata and act on it.

The inputs are basically a sentence: mode (enabled or disabled, default enabled), and tail_trim_frames (default 1, 0–24). That's it. When mode is enabled, the node writes the trim count into the cine_linx metadata (shotboard_tail_trim_frames / cine_tail_trim_frames); when disabled, it writes 0. Outputs are the modified cine_linx and a report string that spells out exactly what got set - handy for confirming the policy landed where you expect.

Where it fits. Planner (V4 or earlier) → Tail Trim Policy → backend. You can drop it anywhere along the cine_linx chain since it just re-tags the dict; it doesn't care what else the plan contains. The report output is genuinely useful the first few times, because it also records the node's own rule of thumb: "Shotboard owns final generated-tail cleanup. Manual video-editor trim remains separate." That's a real distinction - this node trims the generated tail before save/collector/editor, it doesn't touch a manual trim you did on an imported clip in the editor.

Install. It's part of the IAMCCS-nodes pack: ComfyUI Manager (search "IAMCCS"), or git clone https://github.com/IAMCCS/IAMCCS-nodes into custom_nodes, then restart. No dependencies beyond the pack itself, no models.

The honest take. You can usually leave the default (enabled, 1 frame) and never think about it again. Where people get confused is expecting this to be a general "cut the last N frames of my video" node - it's not. It's metadata for the shotboard pipeline. If you connect it to a cine_linx that never flows into a shotboard backend, it does nothing but add a field and print a report. And if your generated clips keep coming back one frame longer than requested even with this enabled, check that the downstream crop node is actually present in the graph - the policy is only a note until something acts on it.