IAMCCS Audio Duration Probe

Sometimes a node is just one good idea done cleanly. IAMCCS_CineAudioDurationProbe measures an AUDIO clip and reports everything about its length: audio_seconds, audio_frames, samples, sample_rate, and delta_vs_target_s (how far it is from a target panel length you supply). That's the whole job, and it's surprisingly easy to underestimate how often you need it.

Why you'd reach for it: video generation is frame-counted, and audio isn't - a 3.7-second clip doesn't come out to a round frame count, and the LTX-2 chunk lattice (8n+1 frames) makes the rounding messier. When you're syncing dialogue audio to a generated video, you need the audio's frame length as a number you can wire into a sampler, not as something you eyeball in a preview. This node gives you audio_frames (fps-aware, rounded up) and audio_seconds as first-class outputs you can feed straight into duration planning. The delta_vs_target_s output is the quiet star: set target_panel_seconds to your intended shot length and the node tells you at a glance whether your dialogue is too long (positive delta) or too short for the panel.

It fits naturally in the IAMCCS Cine dialogue flow - pair it with IAMCCS_CineAudioInfo or the timing reconciler to keep a shot's audio and video durations honest before you commit to generation. But it's also perfectly good standalone: any graph that needs "how many frames is this audio, at this fps."

Mechanically it's trivial under the hood - divide sample count by sample rate, multiply by fps - which is exactly why it's trustworthy. No models, no cleverness, no failure modes beyond feeding it an empty AUDIO.

Installing: part of IAMCCS/IAMCCS-nodes - ComfyUI Manager → search "IAMCCS", or cd ComfyUI/custom_nodes && git clone https://github.com/IAMCCS/IAMCCS-nodes.git, restart. No models, no extra deps.

The one thing to keep in mind: audio_frames rounds up (ceil), so it's the "at least this many frames" number - perfect for planning a video that must contain the whole clip, and slightly pessimistic if you're computing exact sync. And if you're wondering why it's called a "Duration Probe" when it clearly does more than measure - that's the pack's naming in action; the extra outputs (samples, sample_rate) are free diagnostics. For a utility this thin, that's a fair deal.