Get Video Stream

Get Video Stream answers a real question: "a container can hold more than one video stream - which one do I actually want?" Think of a Blu-ray with multiple camera angles, or a file with a high-bitrate main stream and a low-bitrate trailer stream riding along. In a real video tool this node would pull stream number N out of a batched list and hand it to the decoder. In the ComfyUI Core Video Nodes pack (Immac/ComfyUI-CoreVideoMocks), it hands you the string "Mock Video Stream" no matter what.

It's one of the pack's "stream plumbing" nodes, and the plumbing is the point. The pack is an RFC sketch - GitHub's own description is "A set of mock nodes for RFC purposes" - and this node is part of the proposed API shape: batch streams in, pick one by index, pass a single stream onward.

The two inputs

• streams - a STRING, force-input only. You wire this from Split Video's video_streams output or from Batch Video Streams.
• stream_index - an INT, default 0, with the author's own tooltip: "The zero-based index of the stream to extract." This is the one you'd actually touch: 0 for the first stream, 1 for the second, and so on.

The single output, stream, is what you'd feed into Decode Video Stream or Codec From Video Stream in a working pipeline. Here it's a placeholder string.

Install

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

Restart ComfyUI. No pip packages, no models, no ffmpeg - pure Python on ComfyUI's own folder_paths. Or use ComfyUI Manager and search "ComfyUI Core Video Nodes."

Worth wiring up?

Only as a shape to study or a placeholder to build a workflow skeleton around. The output is fake, and anything downstream of it will be operating on nothing. If you genuinely have a multi-video-stream file and need to select and decode one, ffmpeg's -map and VideoHelperSuite (VHS) are where that actually happens. The pack sits at two GitHub stars with no community discussion behind it - it's a proposal, not a product, and this node is one small piece of the proposed interface.