I have a video recorder with UK TV tuner, recorded programs can be exported to USB or via network to a .ts file, which I understand is mpeg2

I recorded two different programs recently; noticing a big difference in file size I used ffmpeg to compare and noticed the following main difference;

Video stream video 1 15000 kb/s
Video stream video 2 2794 kb/s

Each video was by a different broadcaster (one UK BBC and one UK ITV) but recorded on the same device so I am a wee bit puzzled; I thought it was the format recorded in that set the file size, it looks like I am wrong if someone could clarify for me please.

Geffers