How to read video stream from local video file or webcamera?

my boss want to show live video in slicer 3d window via Video capture card and local video , I searched for information about the community and came to the conclusion that webcamera can be implemented using the Plus plugin (I’m not sure if it’s correct), but how do I implement local video streams?

SlicerIGSIO extension adds compressed video file reading/writing/recording/replaying (using Sequences module).

There are a lot of legal complications around usage of video codecs, so we only support the unencumbered .mkv file format and VP9 codec.