Split Video

Of all seventeen nodes in Immac's ComfyUI Core Video Nodes pack (Immac/ComfyUI-CoreVideoMocks), Split Video is the one that best explains what the whole pack is trying to say. It's the demuxer: it takes a single video file and breaks it into the streams that live inside it. And its three outputs - video_streams, audio_streams, subtitle_streams - are basically the pack's thesis written in ports.

That's the mental model every video workflow hangs on: a file like clip.webm is a container holding separate streams, and a video is really "the picture stream plus the sound stream plus the caption stream, all riding in one box." This node demuxes the box. In a real implementation that's exactly the step you'd do before you touch any of the streams individually - pull the video out to decode frames, pull the audio out to transcribe or replace it, pull the subtitles out to edit them.

What it actually does

One input: video, a STRING you wire in (from Load Video, typically). Three outputs, all strings: video_streams, audio_streams, subtitle_streams. What you get out is the literals "Mock Video Streams", "Mock Audio Streams", and "Mock Subtitle Streams". The demuxing is faked, but the shape is real, and it's the only node in the pack that hands you the complete container/stream picture at a glance.

Install

cd ComfyUI/custom_nodes
git clone https://github.com/Immac/ComfyUI-CoreVideoMocks

Restart ComfyUI. No pip dependencies, no model downloads, no ffmpeg - pure Python on ComfyUI's own folder_paths. ComfyUI Manager finds it under "ComfyUI Core Video Nodes."

Worth your time?

If you're new to how video files work under the hood, honestly, this mock might teach you more than a working node would, because the three outputs make the stream concept visible instead of hiding it behind a single file path. If you need real demuxing - extracting audio or subtitles from an actual file - that's ffmpeg territory, and on the ComfyUI side VideoHelperSuite (VHS) is the tool people actually use. Treat this one as the textbook, not the tool. The pack itself is an RFC sketch with two GitHub stars and no community discussion behind it, so set your expectations accordingly: it's here to demo an API, not to ship video.