Depending upon your location. You may find that one or aanother brand of muxer is particularily popular (in my area mostly robot at the higher end and atv at the lower). BIG caveat if you are working with copies, these may or may not contain the same muxer info as the original. If not copied correctly this data (inserted in the videi blanking interval) may not survive the copy process. I do this type of work for a major prosecutor so if you need any info you can contact off forum.
good luck,
Jerry
gkling9901@att.net