[jeven]

Hello everyone, I apologise for my newbiness, but I haven't owned a television in years, so am not too clued up on video.


I bought a new TV recently - a cheap Sharp - 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.

[emptybox]

Yes, the "TS" in the file name stands for transport stream, and is just as broadcast, with no loss or compression.
The MKV and AVI files are compressed and some of the information has been lost, but as you say, you can get much lower file sizes for very little loss of quality.

The only answer would be to convert the TS files into say MKV and then put them back on the external drive, thereby saving yourself space.
That's presupposing that the TV will play back those files directly from the drive?

[jeven]

Thanks for that explanation...I don't think I could be bothered converting those files and putting them back on the USB - even if the TV could play them.

I'll just play my own avi and mkv files via HMDI from my phone or tablet and leave the TV's USB alone.

Still, I'm seriously impressed with what this telly can do for £110 - it's just 19", but that's all I need - the last TV I had was a square CRT box which only got the 5 analogue channels. This was circa 1995/96, before Freeview.

[chrisjr]

On a 19in screen unless you get really really close you are not going to notice so much the various compression artefacts introduced by the various forms of video compression.

Different video codecs compress the raw video with different degrees of efficiency. MPEG 2 as used by DVD and Digital TV is not one of the most efficient. And the bitrate that you choose to encode the video to will also have an effect on both quality and file size (better the quality, bigger the file size for the same video codec).

And if you think 2.8GB is big consider that many cinemas use digital projectors these days. I would guess that the digital version of the film as shown in the cinema is more likely to be in the hundreds of GB. Even the DVD version of the film could be double the size of the broadcast version.

[jeven]

So what would be the equivalent in old VHS? (if those could be measured in Mbs)

I seem to remember a lot of those VHS videos looked pretty bad.

I'm just used to viewing small mkv and avi files on my laptop screen, really, so a 19" screen is a step up for me.