Transport Stream to HDMI conversion query

Tim.ivn

New Member
Hi

I would be very grateful if the experts on this forum could answer this query.

When the HDR FOX T2 converts the broadcast transport stream into an HDMI signal, does it do any image processing (apart from the up-scaling of SD) or does it leave the images undoctored?

Does the HDR FOX T2 use an up-scaling method which are prone to artefacts such as "ringing"?

Thank you very much.
 

Black Hole

May contain traces of nut
Whatever the incoming broadcast (or recording playback) resolution, the HD/HDR-FOX resamples it to the selected output resolutions, which are 1080i/p, 720i, and 576i. Obviously of the output selection matches the input, no resampling occurs. If your TV has a 1080 screen, it would also resample the broadcast to 1080. You can thus choose whether to have the TV or the Humax do the scaling, but to be honest the Humax resampler does a pretty good job IMO. There is no reason to believe any other processing goes on.

There is another factor to throw into the mix: TVs "overscan" the tuner input, enlarging the image by about 4% and only showing you the centre, thus losing any edge artefacts (I don't know why they do this with digital TV, it was only necessary for analogue, but the broadcasters still rely on it to cover their sins). Often there is no way to turn this off for the tuner, but is selectable for HDMI input. The overscan setting means another resampling even if you sent the HDMI as 1080.

More info HERE (click) and HERE (click).
 
OP
T

Tim.ivn

New Member
Hi Black Hole

Thank you very much for your very informative reply.

I have transferred some SD recordings from my HDR FOX T2 on to my 15" laptop and have played them full-screen using VLC and the quality is superb without any "ringing". Am I correct in deducing from what you have said in your reply that if I connected my HDR FOX T2 to a 24" HDCP-compliant monitor using an HDMI cable, the quality would be just as good?

The reason I started this thread is that I currently have an old CRT television and I am wanting to upgrade. However, whenever I have seen SD footage on HD televisions in showrooms and other people's homes, the quality has without exception been awful with lots of "ringing" and blotchy colours. I think that this must be because the images are processed to death. That is why I am wanting to get a monitor instead of a television. I am considering getting an Asus VG248QE or VG278HE.
 

Black Hole

May contain traces of nut
The StDef recording you transferred was only processed by VLC - not the Humax. All the Humax did was copy the incoming TS data stream to a file (encrypted on the way, decrypted when you copied it to USB - more info see Things Every... section 5).

Yes, the Humax HDMI output is perfectly acceptable, any color oddities will be down to the cheapness of the display. Once you ditch your CRT TV and upgrade to a hi-res LCD/LED/plasma you will wonder why you struggled on so long (but please don't buy supermarket own-brand, eg Technika). Some people are still using CRT TVs, because they have a large investment in a top-of-the-range huge B&O or something. Hi-res CRT monitors (as opposed to TVs) are still the gold standard though.

The reason for poor images (and I don't know what you are expecting) is poor TVs or TVs that are too large. Spend £400 on a 32" and you should be happy. 50" is stupid unless you intend to play Blu-ray or sit 20 feet from it.

You don't need to buy a monitor just for watching telly, even HiDef. Monitors are also more expensive than TVs, unless you need the mega-resolution for something else (eg PC desktop or games). In fact, having too much resolution available actually makes the lower res pictures appear worse. The TV tuner is also a useful back-up for when the Humax is busy recording two other programmes (or is otherwise unavailable).
 

petrev

Member
Hi,

Poor images in shops is normally due to the use of "Showroom" settings - Max Contrast, over saturated and with lots of sharpening applied. Great LCD TVs can be made to look awful because they are all fighting to look the brightest and grab attention. I had to spend quite some time in the store with the remote trying to get a decent picture.

As BH says use of a Computer monitor with more than 1080 res is actually not a good idea as the upsampling can make things look pretty dire in comparison to the native res.

HDMI source - Turn off Overscan - Set sensible Colour/Contrast/Brightness/Sharpness - Defeat most processing if not all (personal choice but I just keep the 200Hz MotionFlow type stuff enabled on my TV)

Some amazing images are out there - just not in the special showroom mode !.

Pete
 
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