Recording live TV: Question about video codecs?

[Jeven]

I bought a new TV which records to an USB flash drive.

So I stuck an 128Gb flash drive in the back and began timed recordings. No problem - it recorded Quantum of Solace (2h 10m) but the file size was 2.8Gb. I understand this is in something called MPEG2-TS, and it's a UK DVB Freeview broadcast, not HD but it still looks pretty good.

But...when I connect my phone via HMDI and play an mkv or avi file (around 300mb - 600mb) it looks and sounds just as good. So my question is, why?

Why so much data used recording DVB television when the quality isn't noticably better than a much smaller dvd or blu-ray rip? I was hoping to be able to store much more on my flash drive, ie. things I've recorded directly from the TV, but if it's nearly 3Gb a movie then perhaps not.

Edit: there's no way of changing the quality of recording - it's just as broadcast.

[CrowdAds]

[Jeven]

What I ended up doing was connecting a 3Tb hard drive to the back of the telly.

That way I have all my flac audio files (2Tb) on there, played through the tv by the remote and my home audio system, plus 1Tb for tv shows and movies. So I don't really care about the size of the tv files - they're just as broadscast.