When I remux the transport stream (.ts file) of a satellite recording to mkv, file size shrinks considerably.
Why is that ?
What is inside the .ts container that gets "lost" during remuxing ?
For testing purposes, I recorded a few seconds of a TV satellite broadcast, resulting in a 4 MB .ts file. I then remuxed this file to .mkv, keeping all streams (1 video stream + 2 audio streams) and got a 3 MB .mkv file.
What accounts for the -25% difference in file size ?
I can attach the files if needed. No reencoding takes place.