Picture Quality getting worse?

[Deleted User][Deleted User] Posts: 745
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Has anyone noticed a big drop in the quality of picture on Freeview?

I've noticed BBC1, BBC3, Channel4, E4, ITV amongst others all suffer noticable blocking (its not picture drop out) during busy sequences. For example, during Jamie Oliver's piece on C4's Richard and Judy today the image became blocky when Jamie whiched his maspacone! I'm not convinced that whisking cheese can be counted as 'busy' either!

In my opinion, Freeview's image is actually worse than a decent analogue image (excluding anamorphic widescreen, of course!).
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  • [Deleted User][Deleted User] Posts: 542
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    davidredge wrote:
    Has anyone noticed a big drop in the quality of picture on Freeview?

    I've noticed BBC1, BBC3, Channel4, E4, ITV amongst others all suffer noticable blocking (its not picture drop out) during busy sequences. For example, during Jamie Oliver's piece on C4's Richard and Judy today the image became blocky when Jamie whiched his maspacone! I'm not convinced that whisking cheese can be counted as 'busy' either!

    In my opinion, Freeview's image is actually worse than a decent analogue image (excluding anamorphic widescreen, of course!).

    I agree. It could just be that I'm getting old, and my eyesight is going, but over the past 6 months or so I have noticed the PQ isn't as good.

    I watched N. Ireland vs Wales recently, and you could see the glow around the welsh player's shirts :confused:
  • [Deleted User][Deleted User] Posts: 437
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    You know, I was flicking over and landed on the end credits of the new Hollyoaks titles on E4, and the quality was dreadful. Maybe it's just me, but lately there's been a fair amount of blocking on quite a few channels. I know there's limited bandwidth, and of course we now have more channels, but it seems to be worse of late. Wonder why?
  • [Deleted User][Deleted User] Posts: 23
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    have found no problems here in Northern Ireland at all!
    Limavady transmitter.
  • meltcitymeltcity Posts: 2,262
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    I think the picture on BBC1 is generally okay, except for studio based stuff with bright lighting and a lot of colour (National Lottery, Star Spell etc). Such scenes are difficult to encode well at standard bit rates, so you see a lot of noise in the picture and the colours are washed out. Football is also a problem when the MPEG encoder struggles to cope with fast motion on a finely textured background.

    In my opinion the worst offenders for picture quality are C4's and ITV's family of digital channels. ITV2 & 3, The ITV News Channel, E4, More4 and Quiz Call all broadcast at a resolution of 544 x 576, 25% less than the standard DVB resolution of 720 x 576 (see this web site for details). This has a dramatic effect on picture quality, and even the best quality material looks unattractive and dull when compared with channels that use the full DVB resolution. (E4+1 does use the full DVB resolution and it looks a lot better picture than E4.)
  • [Deleted User][Deleted User] Posts: 745
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    Do these channels broadcast at a better resolution on Sky and Cable?
  • [Deleted User][Deleted User] Posts: 40,102
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    On my portable TV in my room, I switched back to 4:3 ratio because I was sitting too far away to read it in 16:9 and I noticed that the pictures of most channels were quite blocky. This was noticible on a 14" TV so I can only imagine how bad it'll be on a bigger screen.

    Quality over quantity is what we want, but it seems we're getting quantity over quality. Boo.
  • [Deleted User][Deleted User] Posts: 336
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    Yes i agree it is getting worse how can they expect to keep and gain viewers if the signal keeps breaking up.
  • [Deleted User][Deleted User] Posts: 333
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    So what do people want? It can't be both ways!! More channels at lower quality.. or less channels at higher quality?

    Until the analogue switch-off happens and we get some more bandwidth for DTT, the blockiness is going to remain.

    Or perhaps, some fantastic new compression algorithm will sort it all out.. perhaps.

    Regards,
  • [Deleted User][Deleted User] Posts: 745
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    For me, absolutely far less channels. Simply because bandwidth will be sold off to allow more channels, lets face it!


    Perhaps reduce it right down to channels from the BBC, ITV, Channel 4 and 5 - with only one or two add ons.
  • markelliottmarkelliott Posts: 3,573
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    meltcity wrote:
    In my opinion the worst offenders for picture quality are C4's and ITV's family of digital channels. ITV2 & 3, The ITV News Channel, E4, More4 and Quiz Call all broadcast at a resolution of 544 x 576, 25% less than the standard DVB resolution of 720 x 576 (see this web site for details). This has a dramatic effect on picture quality, and even the best quality material looks unattractive and dull when compared with channels that use the full DVB resolution. (E4+1 does use the full DVB resolution and it looks a lot better picture than E4.)

    I totally agree with you. I too ain't keen on the picture quality of the channels that broadcast at 544x576. E4+1 has a far superior picture to E4, as E4+1 broadcasts at the 720x576 higher resolution. However, I never watch E4+1 because the picture and sound are still out of sync! When are they going to sort this out? :rolleyes:

    What I don't understand is why do the most popular digital channels run at 544x576, ie. E4, More4, ITV2, ITV3 etc... yet channels like Ftn, UKTV Bright Ideas, UKTV History, Sky Travel, Ideal World etc... all run at the higher 720x576. I think this is pathetic. However, that said I am no fan of mux C and D, as for some reason the picture is all jerky on them, would this be something to do with GOP sizes? :confused:

    And look at the state of the Top Up TV streams - picture quality will never be more than 2900kb/s on any of their channels, but could overtime reach as low as 1900kb/s if more channels are added to the mux. Also, alot of their streams are on 128kb/s audio!!! Truely awful. I don't have Top Up myself, but I can imagine how bad the picture and sound is from their channels. :rolleyes:
  • [Deleted User][Deleted User] Posts: 40,102
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    Can Ofcom not do anything about this? Clearly we aren't happy.
  • [Deleted User][Deleted User] Posts: 336
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    dttuser wrote:
    So what do people want? It can't be both ways!! More channels at lower quality.. or less channels at higher quality?

    Until the analogue switch-off happens and we get some more bandwidth for DTT, the blockiness is going to remain.

    Or perhaps, some fantastic new compression algorithm will sort it all out.. perhaps.

    Regards,

    Get more channels then upgrade quality after the switchover ( i must admit the signal quality isn't that bad its just break ups now and then and as i have an indoor aerial all i have to do is reposition it)
  • [Deleted User][Deleted User] Posts: 333
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    Another idea, would be to shove radio stations onto a single mux. That would probably be best, as I think as percentage DTT radio listeners are still probably only a few percent - it would give broadcasters a little more room to manoeuvre with compression technologies.

    How many radio stations at 64Kb/sec can fit into a 64QAMmux ?

    Anyway.. The difference between E4 and E4+1 is barely nothing to do with picture size dimensions.. What affects your picture quality more is the aerial you have on your roof, the strength of the signal you receive (which can affect blocks of interference on your TV), how good your DTT set-top box is at decoding and displaying your signal into a good picture, how good your TV is at displaying the picture, if the mux is a 16QAM or a 64QAM the algorithm used to compress the data stream will vary depending on the number of channels sharing the bandwidth, how much interference between the transmitter and receiver there is including external factors like Sunspot activity, thunderstorms, other radio signals, etc. etc..

    My picture quality up here in Winter Hill across all channels is pretty damn good, signal strength is also very very good, the weakest is the SDN multiplex, but that's to be expected and it's pretty much the same situation across the entire country (for those that can get the SDN multiplex).


    Regards,
  • [Deleted User][Deleted User] Posts: 336
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    Why does Freeview have Radio stations if we got rid of them could we put more channels in there place or do radio stations take up no space
  • [Deleted User][Deleted User] Posts: 333
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    Radio stations do indeed take up space - it's just that they don't take up as much space as a single TV channel would..

    Essentially, it's because there's more data to transmit with a TV picture - you have data for the picture, the audio, subtitles and maybe digital text carrier information etc.

    Where as radio channels just have an audio stream, plus some basic text information - now and next, current track playing etc. + the little graphic that gets sent to the DTT. So it's a lot less.. hence less space across the multiplex.

    I think it's roughly about 6:1 - Radio channels to a TV channels.. but that will depend on transmission rates. It may be a little more perhaps. I've no doubts someone else will pop along with a post saying it's X many stations to 1 TV.. and then someone else will come along and so no that's no quite right.. :D we'll see.

    Regards,
  • GaryBGaryB Posts: 4,259
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    Why does Freeview have Radio stations if we got rid of them could we put more channels in there place or do radio stations take up no space

    They take up very little space compared to TV stations. Something like 128-192Kb per second IIRC, compared to many megabytes for TV. You could take all the radio stations off of a MUX and it would hardly affect the TV bitrate at all.

    The main issue is that the slots generate cash, so quantity will always win over quality. Intellect, who represent the manufacturers are trying to do something about it. Manufacturers (I work for one) receive many calls complaining about the quality of pictures on Freeview, virtually all of which are the blocking issues mentioned above. A few are aerial problems but most are due to the bandwidth limitations, not the product, but you try explaining to someone who has just spent £1800 on a TV and isn't happy with the picture.
  • [Deleted User][Deleted User] Posts: 2,996
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    davidredge wrote:
    Has anyone noticed a big drop in the quality of picture on Freeview?

    I've noticed BBC1, BBC3, Channel4, E4, ITV amongst others all suffer noticable blocking (its not picture drop out) during busy sequences. For example, during Jamie Oliver's piece on C4's Richard and Judy today the image became blocky when Jamie whiched his maspacone! I'm not convinced that whisking cheese can be counted as 'busy' either!

    In my opinion, Freeview's image is actually worse than a decent analogue image (excluding anamorphic widescreen, of course!).
    Considering their haven't been any changes to BBC 1 or 3 that's either poor reception - so the blocks themselves moving/disappear or just noticing worse quality on ITV/C4 channels and now looking more closely at other channels. Either that or you have new equipment.
  • [Deleted User][Deleted User] Posts: 4,490
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    its not just freeview, i have telewest cable & sometimes especially football the quality is terriblle especialy on itv, channel4 & more 4
  • markelliottmarkelliott Posts: 3,573
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    its not just freeview, i have telewest cable & sometimes especially football the quality is terriblle especialy on itv, channel4 & more 4

    That's because NTL & Telewest recompress the streams. :eek:
  • [Deleted User][Deleted User] Posts: 46
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    I've noticed it too in the last few months. Generally worse across the board although Quiz Call, E4 and QVC in particular are dreadful (it's my Mum who watches QVC by the way!!)
    abc1 has also really gone downhill. It always looked great for me (although I've often noticed people on DS complaining about it) but now it's shocking! - Thing is we all know why though.
    Don't get me wrong, it's really started annoying me too lately but at the end of the day it's still basically a free service once you've bought your box, so how much can we reasonably moan about it????
  • John259John259 Posts: 28,326
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    Picture quality is very subjective and very difficult to measure purely by eyesight.

    It's vital to compare like with like as much as possible. Same programme source (new VT, old VT, film, line converted, aspect ratio converted, etc) ideally the same programme, same studio lighting, same room lighting at home, same television with brightness and contrast the same, same person watching and in a similar mood, etc, etc, you get my drift.

    I've noticed more blocking on some channels of late. As yet more channels get added this is likely to get even worse. I have read on DS that if your reception is marginal then introducing more channels can reduce it to below the critical level.

    However, I have also read on DS that BBC1 in England is not statmuxed and has a fixed data rate. Has anyone definitely noticed a decrease in picture quality on BBC1 with all other factors being equal? I haven't, but I only watch the channel very rarely.

    OfCom should be far more pro-active regarding the regulation of digital television technical and artistic standards IMHO. The term "laissez-faire" comes to mind...

    John
  • [Deleted User][Deleted User] Posts: 2,996
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    John259 wrote:
    I've noticed more blocking on some channels of late. As yet more channels get added this is likely to get even worse. I have read on DS that if your reception is marginal then introducing more channels can reduce it to below the critical level.
    There is way of adding more channels (64QAM) that makes reception more marginal (like ITV and 4's channels five, top up tv, abc1 and various shopping channels are at the moment) by giving 50% more channels at the same quality, but that hasn't been done to any channels that didn't start off with it yet (on Freeview), it is anticipated at switchover but there will be other provisions to make the signal much better than at the moment nevertheless. Introducing more channels doesn't drop quality on all channels just on the ones its grouped with, and so BBC channels are not affected.
  • [Deleted User][Deleted User] Posts: 745
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    The best way to describe my experiences with poor picture quality on all of the above channels is a stable picture but you can noticeably see the image is made of small blocks.

    I'm 100% sure it is not signal drop out.
  • markelliottmarkelliott Posts: 3,573
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    The picture quality of some of the channels on Freeview, ie. E4, More4, QVC etc... trick my eyes into thinking that I'm watching a recorded programme on video tape. These channels seriously do look like VHS quality.

    QVC has disgusting picture quality, the bloody stream has problems rendering the presenters hair! :eek:

    Quiz Call, again, has disgusting picture quality - the amount of blocking and walking ants in unbelievable. Channel 4 have shot themselves in the foot there - they know the stream for Quiz Call is low quality, and they go and make the studio and graphics bandwidth hungry - lots of bright red graphics, red walls and flashing lights etc... The picture quality is shocking - it looks similar to an Internet stream. Taking a look at Quiz Call on Sky, the picture quality is excellent - barely any blocking at all.
  • chrisychrisy Posts: 9,418
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    And look at the state of the Top Up TV streams - picture quality will never be more than 2900kb/s on any of their channels, but could overtime reach as low as 1900kb/s if more channels are added to the mux. Also, alot of their streams are on 128kb/s audio!!! Truely awful. I don't have Top Up myself, but I can imagine how bad the picture and sound is from their channels. :rolleyes:

    Are you sure about this? It has been mentioned on this forum previously that Ofcom's quality standards are 256kbps for audio on TV channels..

    Looks like this is just one of those DS myths though, and only a recommendation. Source
    Ofcom wrote:
    Source Coding of Audio Signals

    Audio encoding conforms to ISO/IEC 13818-3 and observes the Implementation Guidelines contained in TR 101 154 .

    It is recommended that the bit-rate used for audio coding are:

    Stereo = 256 kbit/sec
    Joint Stereo = 192 kbit/sec

    For the purpose of this section, the main service is defined as being the principal audio service connected with the Qualifying or digital programme service.

    Additional audio channels, such as Audio Description or foreign language services, within the programme channelmay be included in conformance with the general requirements outlined in TR 101 154 .

    When an Audio Description service is transmitted it is recommended that it be broadcast at a minimum bit-rate of 64 kbit/sec.

    When looking for the above, I stumbled on this:
    Ofcom wrote:
    6 The technical quality available from a directly fed transmitter (i.e. one receiving its signals from an SHF link, land line or satellite, without a rebroadcast link en route) used to broadcast Channel 3, 4, 5 in analogue or digital form, or S4C Digital, should not normally be more than half a grade worse (in sound or vision) than that available at the broadcast licensee's transmission output. Perceptible transient distortion caused by digital compression is permitted provided it is not annoying to the viewer** .
    ** An impairment tape is to be made available by the ITC illustrating acceptable levels of perceptible transient distortion
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