Occasional micro-stutter on all media (1 Viewer)

[Caesium]

MediaPortal Version: 1.2.0 RC
MediaPortal Skin: Maya
Windows Version: Win7 x64
CPU Type: AMD A8-3850
HDD: Crucial m4 60GB
Memory: 8GB DDR3
Motherboard: Gigabyte A75M-UD2H
Video Card: AMD A8-3850 (HD 6550D)
Video Card Driver: 11.8
Sound Card: onboard Realtek
Sound Card AC3: n/a
Sound Card Driver: 6.0.1.6368
1. TV Card: BlackGold BGT3630
1. TV Card Type: DVB-T2/T/C/S2
1. TV Card Driver: 8.1.1.1
2. TV Card: BlackGold BGT3630
2. TV Card Type: DVB-T2/T/C/S2
2. TV Card Driver: 8.1.1.1
3. TV Card:
3. TV Card Type:
3. TV Card Driver:
4. TV Card:
4. TV Card Type:
4. TV Card Driver:
MPEG2 Video Codec: PDVD11
MPEG2 Audio Codec: ffdshow rev3972
h.264 Video Codec: PDVD11
Satelite/CableTV Provider: Astra 28.2
HTPC Case:
Cooling:
Power Supply: Seasonic 400W
Remote:
TV: Samsung UE46D8000
TV - HTPC Connection: HDMI

Hello,

I have a small problem which is driving me nuts and two days of googling haven't been able to solve.

When watching any media, be it live tv, recorded tv, or a film from HD, I have very occasional "micro-stutter" I believe is the right term; basically it looks like a frame is displayed twice. This only happens once every few seconds, and is only really noticeable on scrolling text (the bottom of BBC News, for example ) or in panning scenes.

I'm convinced it's nothing to do with refresh rates; I have turned on Dynamic Refresh Rate, and the TV is at 50Hz (for TV, I'm in the UK), and 24Hz for my film in an MKV, which matches my sources. Pressing Shift-1 shows stats and the red line is completely flat. It does not move when this stutter happens, the entire scrolling graph just halts for a fraction of a second along with the rest of the image. The amount of "Drops" does not increase either. It's almost like it's happening in the TV rather than MediaPortal, but why would this be if the refresh rates are matched?

Random things I've tried with no success:
* Every different video codec available to me (ffdshow, ffdshow DXVA, MPC, PDVD11, Microsoft DTV-DTD)
* Every different audio codec available to me (ffdshow, Microsoft DTV-DTD)
* VMR9 and EVR video renderers
* MP Audio Renderer
* Setting MediaPortal to RealTime priority, setting affinity to 1 CPU

It also happens in Debug mode, logs from which are attached. Any clues? Anything at all?

Small edit: just forgot to mention that I tried recording a few seconds worth of some scrolling movie credits off live TV, and repeated replaying of it shows the stutter happening in a different place every time; so it's not the source.

Thank you!

 

[mm1352000]

Hi Caesium

You're correct in that there doesn't seem to be a problem with the source. Do you get dropped frames at all when you first turn on TV? It is just that I see a handful of dropped frames in the EVR log.

mm

 

[Caesium]

Hey mm, thanks for picking this up

Yes, when I first turn on TV there are a few dropped frames, but that quickly settles down. You're right there are a few drops in that evr log but they don't correspond with what I see. It seems nothing is logged for the stutters I'm seeing.

I just ran another test and watched the figures again and saw a total of 2 dropped frames (and corresponding evr log entries), but the stutter far more often than that. If nothing is logged, is there anywhere else to look?

 

[mm1352000]

Hey mm, thanks for picking this up

No problem - I just hope I can help!

Yes, when I first turn on TV there are a few dropped frames, but that quickly settles down. You're right there are a few drops in that evr log but they don't correspond with what I see. It seems nothing is logged for the stutters I'm seeing.

Okay, that's what I was wanting to check.

I just ran another test and watched the figures again and saw a total of 2 dropped frames (and corresponding evr log entries), but the stutter far more often than that. If nothing is logged, is there anywhere else to look?

The TsReader and TsWriter logs, looking for continuity issues and time adjustments, however I've already checked there and I don't believe that is the problem. When you have the appearance of dropped frames occurring but the timing is not consistent (with respect to the source material) then generally it rules out source and codec related issues because playing a consistent source with a consistent software setup should lead to a consistent outcome. This suggests wider problems like driver issues, refresh rate matching, heat, DPC latency, and other unusual things.

If I were you, the first thing I'd do is check my CPU and GPU utilisation and heat levels during playback. They shouldn't be sitting too high. Then I'd check my Catalyst settings - ensure all the post processing is turned off, and turn on "enforce smooth playback". Fiddle with different output resolutions and refresh rates. You may also want to consider rolling back to Catalyst 11.4 as there have been various problems reported with later versions (although 11.8 seems better) - make sure you take an image of your current setup before you do that. I mentioned DPC Latency - you can check that with the DPC Latency Checker.

See how you go with those things for a start...

mm

 

[Caesium]

Hello again

CPU load is around 5% when playing media - it's DXVA offloaded so that sounds right to me. I haven't got anything installed to check GPU load at the moment though, I'll try and find something tomorrow. HWMonitor claims the CPU is at 25c while playing HD tv.

I've had a play with the catalyst settings; enforce smooth playback is on, and I tried turning the other enhancements off/on but no difference there.
Also tried setting the TV at 1280x720, exactly the same. I forced it to 60Hz as well just to check and predictably the juddering was much worse but I'd expect that. But it did confirm that it's right at 50Hz, perfectly smooth apart from this once-every-few-seconds thing.

I tried DPC Latency Checker and it did throw up a huge red bar once every 30 seconds which turned out to be the network card. Disabling that and playing TV was a little tricky seeing as my TV Server's MySQLd is on my nas, but I managed it in the end by starting TV then disabling the network card. With the network card disabled DPC shows a steady stream of all green but it didn't fix the issue sadly.

So that just leaves trying 11.4 cats - I'll hunt for a download link for those tomorrow and give them a try.. 4:30am so getting on for bedtime
My only concern with trying those is they won't have support for this CPU/GPU combo - it's actually an APU, one of AMD's new Llano offerings (aka Fusion). Anyone else have one of these and have it working 100%?

One thing I've noticed in shift-1 output is the Measured refresh and Act FPS both sit at around 49.873 on 25fps (50Hz TV setting) content. Is this normal? Should they be exactly 50.0 or is this sort of variation ok? Just watching it now and render time is about 7.2ms, raster offset 16.8ms. I have no idea if these values are good or not.

More fiddling tomorrow - thanks for the help so far

 

[Jay_UK]

Hi there,

When checking the render stats (shift 1), you say everything is flat, but how are the tear lines (parallel white lines moving across the screen at the top), are they nice and parallel and "clean" most the time, and then all fuzzy//torn when the micro stutter occurs?

Cheers,

J.

 

[jameson_uk]

Two possible issues. One is the remote mysql database. The other is de-interlacing. Is all the material that stutters interlaced? (The ticker bar on BBC news is a good test of de-interlacing as mixes 25p and 50i content AIUI)

 

[Caesium]

Hey guys,

jameson_uk - I don't think it's mysql as it happens on movies on HD as well which shouldn't be touching it. Also, they are 720p/1080p so not interlaced. I didn't know the BBC ticker bar did 25p content, is there any way to tell when it's doing what?

Jay_UK - the vertical lines at the top pause for a fraction of a second like everything else, but remain intact and clean.

So, today I'll try 11.4 (and maybe the 11.9 that's popped up).

If that doesn't fix it, I'm starting to wonder if the onboard GPU is the problem. I'm quite tempted to pick up the cheapest NVidia I can find just to test this theory. Would the following do the job?
EVGA 512MB GeForce G210 GDDR3 NVIDIA Graphics Card - 512-P3-1311-KR - Scan.co.uk
Sadly the only other GPU I have lying about that'll fit is a GeForce 7100GS which I doubt is up to the job.

It claims to do CUDA and PureVideo HD. At £23 it's worth a punt to see if the problem goes away.. I did want to avoid an external GPU, it makes the Llano a bit of a pointless buy, but maybe it would be resolved in time with newer cats.

 

[mbuzina]

I would be interested in hearing your findings, as my next htpc is planned with the same "APU" as you use.

 

[Caesium]

Couple more updates..

GPU-Z says the GPU temp is 26c which makes sense seeing as it's the same chip as the CPU. It puts GPU usage at 55% while playing video, whether it be SD or HD. Changing the onboard processing features doesn't really seem to affect that either.. Making me wonder whether it's accurate, though it does drop to 4% when video isn't playing. Maybe the onboard processing simply doesn't consume that much power on it's own.
Memory usage (dedicated) is about 440MB, dynamic 67MB. GPU currently has 512MB mapped to it. I can try bumping that up to 1024 in the BIOS.

11.4 catalysts wouldn't install - they just gave no option for the Display Driver to be installed at all. I guess it's because this card isn't supported by them.

I've ordered an NVidia GT 520 (decided a 210 was too weedy) to try, it should arrive tomorrow. More reports then.