Sbs Poor Picture Quality

[pneu]

Hey guys

As you may be aware there is a problem with the picture quality on SBS where the picture is very aliased and flickery. I have just spoken with SBS regarding the issue and was told they are not aware of any faults and have not received any complaints from other viewers. They said they need at least 3 complaints before they can look into the problem.

I am asking that anyone who is experiencing the problem to please call SBS on 1800 500 727 and report the problem.

There has been some discusion of it already in this thread.

The problem may not affect all states but so far it has been noted in Adelaide, Sydney and QLD.

Thanks

[DrP]

What UTTER and TOTAL BS. Not heard of the issue my arse. Come on, I know SBS and ABC like to deny that faults exist, but enough is enough. I called back when the issue was first mentioned on this forum and I know directly of 12 other people that have called and complained.

Treat SBS like it treats you - with complete and total contempt.

[pneu]

I called back when the issue was first mentioned on this forum and I know directly of 12 other people that have called and complained.

Oh what, 12 people! When I called they definitely said they hadn't received any other complaints. Maybe they don't actually know what is going on or how to fix it.

I can only encourage that people call through and let them know.

[DrP]

There is speculation in the other thread that it has to do with SBS' telecast of a cricket match in HD, ie they've rejigged their setup so instead of being fed from the SD side its now fed from the HD side but that means upscaling all their SD sources to HD (done quite poorly too) and then down scaled to SD again. If you think HD looks bad, take a look at the complete disaster that is SBS SD.

[ckent]

I am asking that anyone who is experiencing the problem to please call SBS on 1800 500 727 and report the problem.

Done.

The person who answered straight away was very polite and took the details herself. She had heard of the problems before, and even offered a possible explanation related to an upgrade on 26 March, but she noted it was probably important to note that everyone had to report their areas separately. This may explain some of the conflicting feedback of some people versus others.

CK.

[DrP]

Not entirely. I know for a fact that there has been more than 3 reports from Mackay QLD and more than 3 reports from Rockhampton QLD regarding the issue.

Its been noticeable enough for people to ring TV repair shops as they thought their set was faulty and people to ring antenna installers as they thought their was a problem with their antenna. I know of repair shops, independent antenna installers, amateur radio operators, independent techs and average people off the street that have called regarding the issue.

Edited April 23, 2009 by DrP

[ckent]

They "fixed" it as usual tonight, just as the 6:30 news was coming on. Very smooth cutover, right in the middle of a busy bit in the opening titles.

CK.

[ckent]

Hey everyone,

My report was handed onto "Alan" from Transmission Services, and he tells me that I am the only one to have reported on the terrestrial picture in Sydney.

He needs two other reports before he can escalate it.

Of course, maybe you're in Sydney and have already rung up? If so, I'll need your first name because he's going to ring me back on Monday and ask who these other people are that have been complaining. So have you done it? Let me know.

CK.

[digitalj]

I had a look at SBS late last night (or really early this morning ) and I found that SBS HD looked better than SBS SD, it was like a lot of the sharpness had been taken out of the SD, i.e. not as sharp as it should be.

Would this mean I have the same problem as others?

My tv is a 480p Plasma.

[djOS]

Here in Adelaide SBS1/2 is truly crap PQ, SBS HD is a little better but not much.

[ckent]

Would this mean I have the same problem as others?

Check it out during the ads; it's really easy to see then. When you see graphics, are the horizontal edges jiggling in a very irregular way? There's the problem.

By the way, I'm quite certain the problem doesn't affect the "NOW" and "NEXT" banners you see after the ad break, nor the brandmark SBS logo in the corner. This all points to a change in the playout systems being the cause.

CK.

[DrP]

My report was handed onto "Alan" from Transmission Services, and he tells me that I am the only one to have reported on the terrestrial picture in Sydney.

ckent, a quick PM reveals that the fault, WRT Sydney, was reported to SBS on the 17th. Either SBS has terrible recording keeping or more than meets the eye is going on.

Edited April 24, 2009 by DrP

[ckent]

DrP, I think what I'm dealing with is a separate thing, where Transmission Services (the guys who are convinced everyone has a bad antenna problem) haven't heard about the dodgy playout equipment upgrade, or even reports of it. The after-hours receptionist that I initially spoke to even knew about the reports of it and the date of the upgrade.

So what I have to do now is convince Transmission Services that there is a problem (coz the bloke can't see it on his TV) because he's gonna ring me on Monday, and if I don't tell him who else has reported it, he will never believe that anything is wrong. Then if management ever asks him about it, he's just gonna say "We looked into it but found nothing". We might get stuck with it if that ever happens.

CK.

[DrP]

Yes, that's possible. I recall a fault on the analogue ABC service here some time back. It took a concerted effort by several people over several days to prod ABC into getting it remedied.

It really shouldn't be this hard.

[grb1503561862]

SBS South East feed looks fine to me here from the Foxtel/Optus C1 sat. maybe it's only the terrestrial broadcasts?

[DrP]

The Austar edition of SBS (presumably this is the NSW metro edition of SBS) showed the same issue last time I looked at it.

[Watershed]

I don't often look at SBS, but I flicked over on the weekend to find a bike race that looked like it came straight from Youtube!

Worst picture I've seen on TV in years.

[dryfry]

Hey guys

As you may be aware there is a problem with the picture quality on SBS where the picture is very aliased and flickery. I have just spoken with SBS regarding the issue and was told they are not aware of any faults and have not received any complaints from other viewers. They said they need at least 3 complaints before they can look into the problem.

I am asking that anyone who is experiencing the problem to please call SBS on 1800 500 727 and report the problem.

There has been some discusion of it already in this thread.

The problem may not affect all states but so far it has been noted in Adelaide, Sydney and QLD.

Thanks

Everyone should ring up at the same time and tell SBS "Your Off the Air". It seems so long as a picture is on the air thats all that matters. Never mind the quality.

[DrP]

I'm sure the response would be "No one else has reported this problem".

[alphamale]

SBS have changed their bitrates recently.

Last year they were using (Sep 08):

SBS @ 5.00mbps (25.8%)

SBS2 @ 3.22mbps (16.6%)

SBS HD @ 7.86mbps (40.6%)

In January 09, they were using:

SBS @ 4.57mbps (23.4%)

SBS2 @ 4.41mbps (22.5%)

SBS HD @ 8.48mbps (43.8%)

Now they are using:

SBS @ 4.14mbps (21.22%)

SBS2 @ 4.13mbps (21.21%)

SBS HD @ 9.20mbps (47.5%)

The above are just snaphots taken from TSReader (Sydney metro).

The normal SBS SD channel has dropped by about an average of 1mbps and is most likely the reason why its picture quality has decreased. I too have noticed an increase in macroblocking during complex scene changes where a higher bitrate is needed to avoid pixellation as well as noticeable jagged edges around curves.

I can understand increasing the bitrate on the HD channel but why should the SBS 2 (or News) channel have the same bitrate as the normal SBS channel. Go figure.

Having said all that, a 4mbps average bitrate should still produce decent quality on non-movement frames but my frame comparison of some old and current Mythbusters episodes prove otherwise which suggests SBS are doing some wrong in the conversion and/or encoding process. The current Mythbusters episodes do look bad compared to when SBS were using a higher bitrate.

Anyway, fwiw, 4mbps for the SD channel is unacceptable for high motion video such as football. It needs at least 5bmps+. Couldn't they at least increase the bitrate for events such as the football (CL, EUFA, FA) while lowering the bitrate for SBS News. Surely that makes sense.

[DrP]

The issue we are referring to is not bit rate related.

[alphamale]

The issue we are referring to is not bit rate related.

Yes you are correct that it's not bit rate related. I just wanted to point out that the bitrate has decreased on the normal SD channel which explains some of the decrease in picture quality such as macroblocking.

The jagged edges around curves or poor anti-aliasing is due to the poor conversion or filtering process that is currently being used on the SBS channel. Case in point, both the SBS and SBS2 have similar bitrates but the picture quality on the SBS2 channel is noticebaly better (ref: the weather map that is shown late at night).

The HD 720p version of the weather map has jagged edges which indicates it is being upscaled from 576i. It looks like the SBS channel is being downscaled from the 720p source whereas the SBS2 channel, they are using the original 576i source.

[DrP]

I really wonder at the reason SBS has decided to stick with a 19Mbit/sec mux instead of bumping to ~23Mbit/sec as the others have. Sure it would mean a slight reduction in the resilience of their broadcast but I think the benefit would outweigh that cost.

[ckent]

Nah, the dodgy double-cross-conversion is probably just skewing the statmuxing all over the place.

Everything is continually "jiggling" now, especially on-screen text and subtitles. If this is at a rate of 25Hz, then it's logically going to affect the HD service not the SD service, and ramp up the HD encoder's requested bitrate.

But on top of that, material which is normally 25fps like film or progressive video is going to lose its natural advantage on the SD channel during global motion scenes, thanks to the incorrect field dominance all the time; it probably depends on lots of small things (frequency of these, duration of these, responsiveness of statmux, delay between SD and HD if any), but you can see that at those times when SD and HD both need lots of bitrate, SD is going to have to encode its macroblocks with each interlace field separately, which is never a way to make 576i MPEG-2 operate efficiently.

(Of course, prove me wrong, and take some TSReader samples during 6:30pm news because that's when they go back to the proper SD picture).

CK.

Edited April 29, 2009 by ckent

[ckent]

I really wonder at the reason SBS has decided to stick with a 19Mbit/sec mux instead of bumping to ~23Mbit/sec as the others have. Sure it would mean a slight reduction in the resilience of their broadcast but I think the benefit would outweigh that cost.

UHF vs VHF?

CK.