I'm working with C# and VLC library, and I wonder if there is way to get hands to VLC buffer (netwoking-cache or so). What I could use, is to save that to my own circular buffer and save it IF needed. Is this possible, or should I just do it with "manualy" on other stream?
There are audio and video callbacks that allow you to access the raw data using libvlc. It does slow down the perf though, understandably.
This sample https://code.videolan.org/mfkl/libvlcsharp-samples/-/blob/master/PreviewThumbnailExtractor/Program.cs shows you how to use the video callbacks to extract frames.
This should be a good starting point for achieving whatever you need to do.