UK Freeview HD New Encoder ?

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oliroe

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#21

Post by oliroe » Mon Feb 18, 2013 10:34 am

Hi

Please could any UK users not experiencing stutter with Freeview HD list what components they're using? If I'm to buy a new graphics card I want to try and make sure it'll actually fix the problem

Thanks

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holidayboy

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#22

Post by holidayboy » Mon Feb 18, 2013 6:01 pm

I'm using a TBS6280 tuner and a GT440 Graphics card.

No issues with flicker since I followed the steps posted for the 29/59 bug.

I've never seen any stutter.
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richard1980

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#23

Post by richard1980 » Mon Feb 18, 2013 6:43 pm

If you pick from the 29/59 GPU list, you should be good to go. However, since UK frame rates are slower than US frame rates (which means the frames have more time to be processed), there may be GPUs that don't work correctly with 29/59 content but they may work with 25/50 content.

Pixelz

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#24

Post by Pixelz » Sat Apr 27, 2013 8:23 am

I've satisfied myself the stutter does coincide pretty well with the changes between 25p and 50i (although the stutter is seen maybe a half-second after the diagnostic overlay reports the change). It's most obvious when there is a horizontal news ticker scrolling across the screen.

However, despite using both an ATI Radeon HD5450 and an HD6570 (with no post-processing and various catalyst drivers from 11.12 to 13.4), the problem persists. I don't think my signal quality is an issue as my internal TV tuner displays the same content with no problems.

Although it's not consistent with the current diagnosis of the root cause, I'm wondering if my CPU or HD tuner might be implicated here.
The CPU is an E8200 45nm Core 2 Duo running at 2.66GHz, and the HD tuner is a BlackGold BGT3650 (4 x DVB-T2). I know the CPU is a few years old, and I noticed some users on this thread have reported they don't see a stutter on TBS tuner hardware.

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holidayboy

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#25

Post by holidayboy » Sat Apr 27, 2013 8:37 am

I'm not sure about the tuner being involved, I'll upload some sample recordings from my tbs card if you like though. I'm not sure if you could predict a few programmes that might exhibit the issue so that I can set them to record maybe? I'll remove my dvb-s2 sources from the hd channels temporarily while I get the clips.
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Pixelz

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#26

Post by Pixelz » Sat Apr 27, 2013 10:00 am

Thanks for your help. The best examples of stutter are on BBC1-HD when they transmit the BBC News channel overnight. If you check the horizontal news ticker at the bottom of the screen it jumps whenever the encoder framerate changes (usually at least one or twice a minute).
Otherwise, the F1 coverage on BBC1-HD exhibits this problem during panning shots. But I don't think there's any F1 for a couple of weeks now.

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holidayboy

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#27

Post by holidayboy » Sat Apr 27, 2013 12:46 pm

I stand corrected! I can indeed see the stutter effect.

I split my dvb-t2 sources from bbc1 hd earlier.

I just flicked over to bbc1hd to see if the triathlon coverage might include graphics similar to the Olympics as I did see the 25/50 effect.

It is indeed showing the frame rate change and I can see the effect that you describe. I'm recording a clip now and will up it somewhere later.

As the athletes are exiting the water after the swim to begin the cycling, the frame rate is switching. The athletes running across the scene are visibly 'stuttering'.
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Pixelz

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#28

Post by Pixelz » Sun Apr 28, 2013 8:42 am

I watched the triathlon and noticed this during the transition from swimming to cycling too.
So we now know it's a problem with both TBS and BlackGold, and we already knew it affects both ATI and NVidia.

I noticed from the Microsoft KB article acknowledging the issue, posted by richard1980, that their decoder "resets the video pipeline" when a change of framerate occurs. That sounds to me like some video data already in the buffer could get discarded, in which case you would always see a 'jump'.

I do have access to a new Core i5 motherboard with integrated intel GPU, so I'm planning to add a FreeView HD tuner there and run some tests. Otherwise, I'm out of ideas as satellite isn't an easy option for me.

In the light of your experience, I'm starting to think that there's something different about the US 29/59 switching that makes it fixable by increasing the GPU power.

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holidayboy

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#29

Post by holidayboy » Sun Apr 28, 2013 8:48 am

I'm running an i5 @2.7 ish GHz (not sure what my setup says on here :???:)

I meant to watch the content on my Echo extender to see what happens there, I'll try today if I get time.
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Pixelz

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#30

Post by Pixelz » Tue May 07, 2013 9:58 am

I've now reproduced this on an ATI HD5450, an ATI HD6570, and an intel P8 Z77 integrated GPU, all with zero post-processing. I've tried latest drivers and older drivers, and I've tried with E8200 and Core i5 CPU's, but when the broadcast switches i50/p25 the stuttering persists.

So I wanted to repeat the question first raised by @oliroe back in February -- "can anyone in the UK who does not experience this problem on FreeView BBC One HD let us know what hardware they're using, please?

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holidayboy

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#31

Post by holidayboy » Tue May 07, 2013 3:35 pm

If anybody gets a bit of time and wants to look for this symptom on their system then I've uploaded a short recording here:

http://sdrv.ms/12aHqG1
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NWW

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#32

Post by NWW » Tue May 07, 2013 4:44 pm

I'll give it a go if you want :) Where do you see an issue?

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holidayboy

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#33

Post by holidayboy » Tue May 07, 2013 5:00 pm

Keep an eye on the swimmers as they run out of the water and across the screen - there is a 'stutter' kind of effect.
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NWW

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#34

Post by NWW » Tue May 07, 2013 5:07 pm

Yep, I see what you mean. But I can't say for sure if it is the fact that I'm running my screen at 60 Hz, or not.

For reference, I'm running a i5-2500k @4.2GHz with a Powercolor Radeon 7950PCS+ @950MHz.

wyerd

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#35

Post by wyerd » Wed May 08, 2013 1:43 pm

I've had a look at your recording and I can also see the stutter as thee swimmers run out of the water and also the high shot when they're collecting the bikes. This is on a 50Hz PDP running on a AMD FM2 A8 5500 with a built in Radeon HD 7560.

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mark1234

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#36

Post by mark1234 » Wed May 08, 2013 1:52 pm

I've tried this video on my 7MC machine, another desktop and my laptop. The stutter was visible on all. 2/3 have Intel CPUs and 2/3 have AMD graphics, the other being the built in Intel on the laptop. I also tried it on my Xbox extender, where it was much better. In fact I don't think I'd have noticed it on the Xbox had I not been specifically looking for it. The Xbox is attached to an old SD TV, not sure if this makes a difference.
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richard1980

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#37

Post by richard1980 » Thu May 09, 2013 12:29 am

I just tested the sample on my system, and I see the stuttering as well, and while the stuttering certainly coincides with the switching between interlaced and progressive, I'm not convinced that is the actual cause. US frame rates are faster than UK frame rates, so my GPU actually has less time to process each US frame than it does to process each UK frame. Therefore, if my GPU is capable of performing the switch in the time allotted for US frames, it should certainly be able to perform the switch when that time limit is increased by UK frames. So this leads me to believe that perhaps there is some other explanation.

Pixelz

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#38

Post by Pixelz » Thu May 09, 2013 12:36 pm

richard1980 wrote:I just tested the sample on my system, and I see the stuttering as well, and while the stuttering certainly coincides with the switching between interlaced and progressive, I'm not convinced that is the actual cause. US frame rates are faster than UK frame rates, so my GPU actually has less time to process each US frame than it does to process each UK frame. Therefore, if my GPU is capable of performing the switch in the time allotted for US frames, it should certainly be able to perform the switch when that time limit is increased by UK frames. So this leads me to believe that perhaps there is some other explanation.
I agree, and I'm now wondering if this is related to other differences in encoding between the US and UK material.

For example, although I haven't got the tools to check it, this sample is presumably encoded as H.264/AVC with MBAFF which the BBC encoder seems to prefer. Are the US samples encoded with a different AVC profile, or as MPEG2, so that the Microsoft decoder can seamlessly handle an i/p frame-rate change, maybe?

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mark1234

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#39

Post by mark1234 » Thu May 09, 2013 1:32 pm

AFAIK, all US content is MPEG2.
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richard1980

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#40

Post by richard1980 » Thu May 09, 2013 7:15 pm

US content is mostly MPEG-2, but some is H.264. It just depends on the provider. I only receive a few channels that use H.264 encoding, but unfortunately they appear as a black screen in WMC, so I can't really do any testing.

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