LTX Director Crop Guides (TJ 2.5)

LTX Director Crop Guides (TJ 2.5) has three inputs, three outputs, no settings. It is the least glamorous node in the LTX 2.5 family and one of the easiest to forget, which is why clips rendered through the Director sometimes come back with a few frames of garbage stapled to the end.

The problem it solves

LTX's keyframe and retake guidance works by appending latents. Drop a guide image in at frame 40, or hand the model a base video to retake, and the guide node inserts its latent into the stream - which makes the latent longer than the clip you asked for. The sampler doesn't care. It just denoises the longer stack. Decode it without trimming and your output runs a handful of frames past the end of the shot, usually as a mush of whatever the guide was.

Those extra frames carry metadata too: keyframe_idxs and guide_attention_entries ride along on the conditioning so cross-attention knows where the guides are. Leave them on and a second stage - a refine pass, a latent upscale - will happily re-inject the same guides at the same positions on already-wrong footage.

So this node does both halves of the cleanup: it slices the trailing latent frames off, and it strips the guide keys off the positive and negative conditioning so they can't apply twice.

How it knows how much to cut

It doesn't guess. It reads a value the upstream guide node wrote into the conditioning - a count of exactly how many latent frames the guides added - and falls back to counting unique positions in keyframe_idxs if that's absent. Then it caps the cut so you can never slice the latent down past a single frame. noise_mask is trimmed in lockstep, which matters: if the mask still covers the removed frames, the region and the samples disagree and the next sampler does something unpleasant.

Outputs are the same three things you fed in - positive, negative, latent - just tidier. If there's nothing to crop, it passes them through untouched.

Wiring

positive and negative must come from the guide node's outputs, not from the Director directly. That's where the crop count lives; feed the raw Director conditioning and the node finds nothing to cut and does nothing.

Typical chain: Director → Guide → sampler (first pass, half size) → Crop Guides → latent upscale / second-pass sampler → VAEDecode. Anything that decodes or hands the latent to another stage should sit downstream of this node, not upstream of it.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/designloves2/ComfyUI-TJ_NODE_STUDIO_ONE.git

Restart, run bash install_requirements.sh (or install_requirements.bat) once, restart again. Nothing extra for this node specifically - it's pure tensor bookkeeping.

Two things worth flagging

If you're using the reference/MSR path, don't reach for this one. MSR injects its references as a prefix, and this node trims from the end, which would eat clean frames instead of reference frames. The source comment is explicit about it: use the stock LTXVCropGuides for that pipeline. On the bundled LTX 2.5 path the reference features are off anyway, so in practice you meet this node in retake mode and on timelines with heavy keyframe guidance.

Second: "my clip has four extra frames of fog" is a crop problem far more often than a sampler problem. Count the frames before you re-render.