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ITV Picture Quality on Sky DigiBox

Discussion in 'Sky Digital TV Forum' started by andyclamp, Jan 2, 2002.

  1. andyclamp

    andyclamp
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    Does anyone see the picture breaking up (is it called Pixeling ??) when viewing ITV on a Sky DigiBox ??

    Only appears to happen on ITV.. Weird..

    This is especially noticable when watching sport.
    Footie which looks great on Sky Sports when watched live, seems to go all "Blocky" when the highlights are shown on the ITV news !!
    Other ITV programs also exhibit the same behaviour.

    I have a Panasonic Digibox connected via scart to a Panasonic TX28PL4 widescreen TV, with the Digibox set to RGB 16:9, and the TV in auto mode.

    Anyone help ??

    Ta, and Happy new year to you all..
     
  2. Kevo

    Kevo
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    Yep, it's the same on NTL Cable too. It's one reason why i'll never subscribe to the ITV Sports channels.

    It's so bad that I always watch the footy on analog with ITV.

    Anybody know why this is so, technically?

    How do Sky and Cable get their feed from ITV Digital?

    Who's at fault?

    I've complained to ITV and they insist it's with the provider and not them!
     
  3. andyclamp

    andyclamp
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    Thanks for replying.

    I know what you mean about having to watch Footie on Analogue ITV, as I have to do it too.. Weird isn't it ??

    Interesting, as especially the highlights sometimes shown on the ITV news have the Sky logo in the corner and were perfect when watched live on SKY earlier in the day..

    I am glad it is not just my setup, as I was starting worry that something was wrong with some of my kit.

    If anyone does no the answer or have any idea's please let me know.

    Ta very much.
     
  4. Stuart Wright

    Stuart Wright
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    The right place for this thread is the satellite forum, so I'm moving it there
     
  5. Kevo

    Kevo
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    HUH ???

    It's about ITV Digital Picture quality, initially on Sky, I mentioned cable and maybe someone else will mention pic quality via an aerial.

    Why move it to the 'Satellite Forum'.

    Please explain yourself.
     
  6. mjn

    mjn
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    the picture from ITV digital is so bad, because of the high compression rates they use. My parents have a ITV digital box, and the picture quality is pathetic, blockiness and pixelation everywhere. They use this ultra high compression, so they can provide you with 100 shopping channels..!!

    I had the unfortnate experience of watching a match on ITV digital, and it waas terrible, it was jerky, the pitch was patches of green and everything.
     
  7. swarrans

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    I assume Sky must be using high compression for ITV too, because as the original thread said ITV is awful on Sky too!
    I can't stand watching ANYTHING on ITV/Sky as it constantly breaks up/loses sound etc. When Sky put ITV on satellite a while back I was really pleased as I assumed I could finally get some ITV programs in widescreen - however, not only is the quality awful but it doesn't look as if ITV is making/broadcasting hardly anything in widescreen!
    Thanks God for the BBC! (I only have the BBC etc channels on Sky via a free to view smartcard so I don't have Sky One etc). However, before I scrapped the subscription to Sky programs it was amazing to me that they didn't seem to transmit anything in widescreen either -- for example, Buffy The Vampire Slayer (OK I admit I'm a closet fan!) was in 4:3 on Sky and widescreen on BBC2.

    However, it's been a while since I subscribed to Sky, so maybe they transmit more stuff in widescreen now?....


    Simon
     
  8. Starburst

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    SKY have no say in how ITV is uplinked or transmitted on the astra platform, the compression problems are all down to ITV squeezing as many channels onto it's transponders as it can.

    Widescreen on SKY?
    LOL, nice idea but apart from a bit of sport and one movie channel they refuse to expand their w/s output.
    They site the lack of w/s TV's as the main reason but it's just corporate ignorance and blind faith that subscribers won't leave because of the lack of w/s material.

    Ridiculous that at this time the only place to see for example Enterprise in w/s is to download it off the net.
    SKY have totally thrown away the right to be considered pioneers in digital television.
     
  9. swarrans

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    As you say Starburst, it's a real wasted opportunity by Sky not to transmit more stuff in widescreen (not sure I really understand their argument anyway when people with 4:3 sets can just select that mode on their digibox even if Sky were transmitting in widescreen).
    Anyway, back to ITV picture quality on Sky......I've just remembered that when the "Hobbit" installed my Sky digital system originally he had major trouble getting a sufficiently good signal stength/quality to receive any channels, so I just checked again and sure enough I only have 40% Signal Strength and 60% Signal Quality. I guess I could be on the limit of being able to receive anything at all, so if ITV uses more compression/lower bitrate than some of the other channels it would explain why ITV is SO bad on my set up.
    Incidentally, I can't understand why my signal strength is so bad - I live in a detached house on the top of a hill with (literally) nothing but sky (with a small "s") between my dish and the satellite!!
    Anyone know what factors effect signal strength - is it possible to live in a (non-visable) "shadow" that's screwing things up for me - or is it likely to be the Hobbit From Sky's incompetance?
    I may try and get a reputable dish installer to come round and see if they can tweak it - or can a use a bigger dish? (I've only ever seen the small ones for digital).

    Cheers, Simon
     
  10. xyznicko2577

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    If you have an unobstructed view of the Satellite you should be able to achieve excellent signal strength and quality, what you have isn't good enough, your digibox will be working overtime correcting errors for that quality signal, get your dish checked by a professional.
    But this is nothing to do with the poor quality picture on ITV, they are overcompressing the channels.
    ITV via satellite is badly set up for quality transmissions each bitstream is transmitting the same output(except for regional progs.) example when football is on, all regions are showing it simultaneously all demanding maximum bitrates(for fast sports action).

    On Sky sports these channels are usually on transponders accompanied by low bit channels.Sky Sports can get better quality pictures because of higher available bitrates from the POT that these channels sharing it's transponder use.
     
  11. Kevo

    Kevo
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    What about other programmes that are being shown nationally on ITV? The News for instance. This doesn't suffer the same pixeling as football.
     
  12. Starburst

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    A news program will have a lot of static backgrounds etc will take up only a few kilobytes of data, this can make a huge difference in quality since mpeg2 is based on only compressing the data that changes bwtween frames.
    The smaller the differences between frames results in very high compression with good quality. On a sports program with every frame having huge changes this results in low compression to get the same sort of quality.

    If the channel hasn't the capacity for the low compressed data streams then the quality dips alarmingly:(
     
  13. JPC

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    No one has mentioned Digi Boxes..... I had loads of problems with my reception...... from an Amstrad.... poor sensitivity..... jurkey movements of moving objects within the picture, poor or no picture for 75% of the time..... if they they re-aligned my dish once it was 20 times.......

    I then had a Grundig..... which was much better...... fantastic detail...... but with some black dots appearing all the time

    Finaly I had a Panasonic 31......... absolutly no problems what so ever...... superb picture, no detectable artifacts at all, ON ALL CHANNELS even during very heavy falls of rain..


    The Amstrad would lose the picture with just a little cloud cover and no rain...
    regards JC:rolleyes:
     
  14. swarrans

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    You're right JC.
    I had my dish re-aligned by CAI professionals (although they still seemed like monkeys to me as they couldn't explain technically what signal strength and quality actually measured).
    The changes they made were VERY minor (they admitted as much) and had a corresponding small affect on signal strength (from 40% to 45%) and quality (from 60% to 75%).
    They did say other digiboxes reacted differently to the signal they received but what amazed me was the SAME MAKE could be different.
    I saw it with my own eyes - they temporaily swapped my Grundig digibox with the same make & model and the figures went up to 75% signal 75% quality. Put mine back and the figures go back to 45% and 75%
    How wierd is that?
    Anyway, I don't know if that little change made the difference but when I watched the repeat of Buffy on Sky at 5pm on Saturday the whole show was fine from a quality perspective whereas the one on Thursday (before I had the dish re-aligned) broke up/had flashes on white/lost sound etc.
    Also ITV seems to have been OK ever since the re-alignment too.


    Simon
     
  15. Starburst

    Starburst
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    Thursdays Buffy problems since it seemed to affect every SKY D viewer in the UK had to be a transponder problem or a major glitch with the hardware at source. Incredibley bad timing after all the money SKY spent promoting a show which turned out to be CUT/EDITED for the 8pm showing and butchered for the inappropriate 5pm slotslot.
     
  16. JPC

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    ###########################################################

    Simon
    I am so glad I have at long last come across someone who has had the same experience as me....... regarding a difference in picture quality even between receivers of the same make and model......

    Ten years ago I bought an Echostar 8700 multi satellite receiver with a 1.2 Mtr Dish
    The Pictures on it were the most incredible video pictures I've ever seen.... including anything I've seen since..... whether Analog or Digital.... and I still have recordings to prove it....

    Everything was in rich Technicolor!!.... (and I mean everything)...
    It was as if it was putting colors into the picture.

    I've never seen such a range of colors in my life on a TV screen.... The strength of non primary colors (colors other than Red, Blue, Green) had to be seen to believed, there was no bleed, no smear, no noise, no moiré....... just outstanding Technicolor Pictures.

    Pictures from the middle east with all the color and sunshine were a joy to watch..... it just didn't mater that you didn't know what they were saying.

    I could never understand why "off air" pictures in "What Satellite & TV" magazine looked so poor in comparison.

    (You have to bear in mind that I was a TV engineer for a while during my varied career......)

    Unfortunately the receiver went faulty and was replaced....
    While the replacement was good by normal standards it wasn't no where as good as the original.......

    To cut a long story short my dealer supplied a number of replacements, but non came up to the standard of that first one....

    I then got Echostar Europe in Holland involved and they were sending me one replacement after another to try.... I even spoke to the Boss of Echostar in the states...... but got no further with my quest to get my original receiver back.....

    Seeing all these different replacements of the same model made me realize that there are more than just subtle differences in picture quality between each one...... there are in fact huge differences between them!!.......

    In my days as a TV engineer there were lots of controls that one could tweak to get the best out of each peace of kit.......... and as a result you could get receivers of the same make and model performing much the same.

    In these days of the microprocessor there are no controls to tweak...... its all decided by the characteristics of each chip and circuit board....... one would think this would narrow the variation between receivers down....... (not up) but to me this doesn't seem to be the case.......

    In view of my findings above........ where does this leave the issue of hardware reviews in magazines like "What Video & TV" "What Satellite" etc.??................. certainly picture quality can be taken as very loosely applying and possibly as not much help at all, if you are a real connoisseur of video pictures.......

    Kind regards to you JOHN CHOWN

    ###################################################################:)
     

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