ITV4 picture quality

BenR

Is it just my set, or is the picture quality on ITV4 rubbish? Helicopter shots are ok, mostly, but any time the riders are in close up (e.g. from the motorbikes) it's all a load of squares, the compression seems far too high. Yesterday with raindrops on the camera lens it was getting on for unwatchable.

Bronzie

Must be your telly because (apart from the rain on the lens) my picture on the highlights show at 7pm last night was fine........................the audio commentary leaves a bit to be desired but that's because Sherwen can't switch off his cliche generator

Pirahna

If you're watching on Freeview you might need to upgrade your TV aerial.

squired

Doesn't it depend on the transmitter. I know that sometimes we get a good picture from Freeview (can even get it without an aerial plugged into the tv). Sometimes we still get a great signal, but poor picture quality (blocky) and sometimes even with the super duper top notch aerial connected signal quality is too low for some channels.

BenR

Thanks guys. We're using freeview and everything seems fine apart from ITV4 (although I must admit that I don't watch most of the channels so there may be other bad ones). The box reports that the signal strength is good and quality is 100%, so dunno what's going on.

oldwelshman

I was going to get new telly recently then had my anual eye test with my company and optician prescribed glasses for readinf and for TV, it is not like HD so saved myself a few quid which is now being spent on my bike

PapaZita

The picture quality on ITV4 isn't great. I can't find the figures right now, but ITV4 has much less bandwidth available than, say, BBC1. This means that more aggressive compression is required, leading to some of the blocking and blurring artefacts that you've noticed.

Bicycle racing tends to involve the sorts of images that are difficult to compress well. All the rotating movements of legs and pedals, fine details in spokes, logos, etc., are a particular challenge for the encoders. The amount of compressed data increases with the 'difficulty' of the video and with the picture quality required. The capacity of the channel is set in advance, so the only thing to do is to reduce the quality until the compressed data fits into the space available.

There are a couple of reasons why helicopter shots might be better than the motorcycle ones. First, the view from the helicopter tends not to have so much detail - it's all trees and fields with a bunch of bikes in the middle, and we don't expect to see all the details on the bikes. Those sorts of images are easier to encode. Secondly, the motorcycle images are transmitted up to the helicopters before being beamed back to the production studio. The uplink from the motorbike will use image compression similar to that used for broadcast, so blocks and artefacts may be introduced at that stage. Unfortunately, those images will need to be decompressed, edited, and compressed again for broadcast. That means that we have to compress the artefacts of the first compression, and blocking artefacts are yet another thing that makes an image difficult to compress effectively.

PZ (digital video encoding R&D bod)

Squaggles

I would have to agree , picture quality on ITV4 seems pretty bad , too much compression , not good for cycling at all .

sanderton

ITV4 runs at a lower resolution than channels like the BBC (544 x576 instead of 720 x 576), and at lower bitrates, so pic quality can be diabolical.

Squaggles

Is this the future of TV then ? Glad I've still got my analogue dish for European Eurosport .

Dingbat

A lot also depends on your transmitter. On my freeview, the ITV channels (all of them) are a lot weaker than, say, BBC, because they're running a lower power output on the transmitter. But as I understand it, the multiplexor used for ITV channels is due to be switched over to other uses once analogue TV is switched off - at which point they should be going 'full power' on another mux and the signal quality should improve.

Having said all that, watching both ITV4 on Freeview and Eurosport on Sky, I've noticed that the bike camera pictures have pixellated a lot more this year than in the past few years. Perhaps the signal between bike and helicopter is running at lower power?

pieinthesky

I have recorded the tour highlights on my Digibox hard drive, everything is ok except there is no sound!!!

Everything else I record is OK. I tried recording ITV 4 this evening and the sound was fine. I now have 4 days worth of highlights with no sound and it is very frustrating.

Anyone have any idea what is causing this?

Rob Sallnow

BenR wrote:

Is it just my set, or is the picture quality on ITV4 rubbish? Helicopter shots are ok, mostly, but any time the riders are in close up (e.g. from the motorbikes) it's all a load of squares, the compression seems far too high. Yesterday with raindrops on the camera lens it was getting on for unwatchable.

I noticed this when trying to grab a screenshot of Boardman's bike to illustrate my point in a thread and noticed it was more compressed than other programmes I've recorded...even caused me to check the recording bitrate but that was BEST.

SteveR_100Milers

I've had no problems with it via Sky.

RichN95.

pieinthesky wrote:

I have recorded the tour highlights on my Digibox hard drive, everything is ok except there is no sound!!!

Everything else I record is OK. I tried recording ITV 4 this evening and the sound was fine. I now have 4 days worth of highlights with no sound and it is very frustrating.

Anyone have any idea what is causing this?

You can get the full highlights programme via the ITV website. The picture size isn't great, but it's useful