Stuttering DVB-T2 HDTV, replace CPU or GPU?

drathan

Standard Member
Our area recently went through the digital switch over, making it possible to receive Freeview HD. I splurged on a new LCD TV with a Freeview HD decoder built in. Happily after the switch over, the HD channels came through loud and clear.

I therefore decided to grab a USB HD tuner for my HTPC. I duly grabbed a PCTV 290e USB DVB-T2 tuner.

The system it is in is a 3 year old machine based around the GA-MA78GM-S2H motherboard with an Athlon 4850e X2 CPU. I am just using the onboard HD3200 graphics. It has 2Gb of RAM and runs Windows 7.

I got the board way back when for two reasons. One to get onboard decoding of Blu rays, and secondly to get a low power machine that could live in an enclosed cabinet. Both of these criteria were fulfilled brilliantly by the CPU/Motherboard combo.

Now, fast forwards to the arrival of the 290e. The PC is fine for reception of SD channels, but it really struggles with HD material. It seems to be just on the edge of its performance. For instance the video can run fine for a few seconds, and then it stutters badly for a couple, and then back to fine, and then ... You get the idea. Task manager reports CPU usage around 80%.

Incidentally, it records perfectly happily without dropping any frames. I can copy the recorded files onto my desktop machine (Core i7-780, 4Gb, AMD 6870) and they play back perfectly fluidly. Annoyingly, I can also use the MC-TVConverter software to losslessly convert the recordings into a transport stream file, which the HTPC plays back fine (minus the audio which is something of a problem). it's just when viewing 7mc, whether recordings or live tv, that the stuttering occurs.

I did some testing, by popping my 6870 card into the HTPC. Hey presto, smooth viewing of BBC HD et al in 7mc. However the image began to pixellate from time to time (particularly it seemed on pans). I understand that may be driver related. Nevertheless the actual frame rate is fine, and CPU usage drops to 20-30%.

I wondered for a start if the onboard GPU was actually assisting with the hardware decoding. I turned off Hardware Acceleration and, using the onboard HD3200, CPU usage went straight to 100% and the video went completely to choppy town.

I have the following results:

i7-870 + 6870 = perfect HD TV
4850e X2 + 6870 = perfectly smooth video, but some pixellation
4850e X2 + HD3200 = unwatchable stuttering.

There seems to be to be a massive difference between the UVD decoding in the HD3200 and the 6870. Is this to be expected? Is the more modern card even better at lifting the load from the CPU? I would have guessed, before testing, that one UVD hardware decoder would be much the same as another, but that does not seem to be borne out.

So it seems I have to decide between a new GPU and a new CPU. Heat IS a major factor with this build, so I can't just throw a 6870 at the problem even if money was no object.

The fastest CPU that the board supports, with the same 45W power consumption as the 4850e is the Athlon X4 610e. Ebay prices are about £50. Alternatively I could drop in a replacement for the onboard graphics chipset. I have no recent experience with the video decoding abilities of the low end of the AMD/Nvidia ranges. Would a modern, sub £50, GPU have the same h264 hardware decoding abilities as the 6870?

So there it is. Would an Athlon 610e with the HD3200 onboard video handle HDTV, or would the 4850e handle it with a discrete, low power, new GPU?

Anyone have experience solving this particular dilemma before?

(BTW - all bios/chipset/GPU drivers are up to date - blu rays at 1080p showed massive corruption before I flashed the onboard VIDEO bios).

Cheers muchly for any sage advice,
 

imilne

Active Member
Your CPU is fine. I used to run HD fine with an ever older model than that.

Look at upgrading the GPU to something like an HD5450 (or whatever its equivalent in the 6xxx range is, if it has one). It'll handle the HD in its sleep, and won't draw that much power over the onboard 3200 you already have. I think it's rated under 20watts.
 

jameson_uk

Well-known Member
There seems to be to be a massive difference between the UVD decoding in the HD3200 and the 6870. Is this to be expected?
Yes. The HD3200 has 40 GFLOPS worth of processing power compared to 2016 of in the 6870. (so just over 50 times as powerful)

The issue is de-interlacing. HD TV is 1080i so whilst the HD3200 can cope with 1080p blurays, addings good quality de-interlacing to this is a step too far.

AIUI when paired with a Phenom II processor you will get better hardware accelerated de-interlacing but it would likely only be a short term solution. Given you can get an ATI 5450/6450 dead cheap (cheaper than that x4 chip) that would do a much better job this would be my suggestion
 

DJBenson

Standard Member
In another thread I posted similar issues to yourself and have the same hardware - I upgraded the onboard graphics of the motherboard to a dedicated ATI 54xx board and I still have problems with the HD channels (BBC in particular) - on a show with a lot of detail (i.e. glitter falling from the rafters of a concert) the picture breaks up into an unwatchable mess - even the most placid of scenes struggles to maintain a solid picture.

I also get some breakup on SD channels despite having a perfect DVB-T/DVB-S signal quality/strength (I have the Blackgold 3595 card).

I am on the verge of doing a rebuild as I'm so fed up of having what should be a powerful HTPC that can't do HD and struggles with SD - this is with Windows 7 Ultimate BTW (32bit).
 

Monty Burns

Well-known Member
Benson, sounds more like his is a buffering issue rather than the Blocking you are suffering. But maybe i'm wrong?

Not sure about the hardware but if it helps I run an Intel I3 using onboard sound n gfx and it can play EVERYTHING i throw at it, including streaming blu-ray images whilst recording two Sky HD feeds (through on board DVB-S2 tuners).
 

drathan

Standard Member
Yes. The HD3200 has 40 GFLOPS worth of processing power compared to 2016 of in the 6870. (so just over 50 times as powerful)

The issue is de-interlacing. HD TV is 1080i so whilst the HD3200 can cope with 1080p blurays, addings good quality de-interlacing to this is a step too far.

AIUI when paired with a Phenom II processor you will get better hardware accelerated de-interlacing but it would likely only be a short term solution. Given you can get an ATI 5450/6450 dead cheap (cheaper than that x4 chip) that would do a much better job this would be my suggestion

Good info, much obliged. Have ordered a 6450 for £32! Worth a punt anyway. What you say about the progressive scan makes a lot of sense. I will update when I have fitted the 6450.

Am using the 6870 quite happily just now. I mentioned the pixelation issue in my first post, which sounds very similar to Benson's problem. I was using the catalyst driver version 11.6. I removed that and went back to 11.4, and it virtually disappeared. I have HD recordings which pixelate badly when played back on 11.6 but are virtually clear on 11.4. May be useful to someone.

I will update when the 6450 gets here. Is it possible to [solved] thread titles on this forum?
 

Monty Burns

Well-known Member
... which sounds very similar to Benson's problem. I was using the catalyst driver version 11.6. I removed that and went back to 11.4, and it virtually disappeared. I have HD recordings which pixelate badly when played back on 11.6 but are virtually clear on 11.4. May be useful to someone.
...


Guys

take a look in my previous post which Benson has confirmed is his problem - Blocking.

If this is what you are seeing I can tell you with 100% certainty that this is a driver issue and its related to DXVA/264 support. It was first noticed with ATI chips many moons ago (and I believe a fix created?) and more recently on I3 55 chipset using mobo on-board HDMI however, Intel updated the drivers and now it no longer happens, at least for me! I can also tell you that Nvidia chips never suffered this problem to my knowledge.
 

Stephen Neal

Distinguished Member
Hmm - I'd be thinking drivers first.

I had an MA78GMS2H motherboard with a 4450e CPU and it had no major problems with BBC HD DSat DVB-S stuff - apart from the period when the BBC changed encoders and ATI/MS had to update their driver/decoder interaction.

jameson_UK is right that de-interlacing isn't optimum - but it should still do motion adaptive (just not vector adaptive) In other words it should do an average/OK-ish job - but certainly shouldn't run out of steam and cause major stuttering.

Have you tried a full re-install from scratch? (Codec packs in particular can be a major problem)
 

Iccz

Member
I will update when the 6450 gets here. Is it possible to [solved] thread titles on this forum?

A mod can do this for you if you so wish - just post asking for it or report your first post in the thread asking it do be done :)
 

Stiggy

Distinguished Member
I also think drivers, especially if you have ever installed Catalyst 11.5.

I had DVB-T2 HD running with a very cheap ATI HD 3470 card and a P4D CPU!
 

Trollslayer

Distinguished Member
Definitely a software problem so what application are you using and is hardware acceleration enabled?
 

SeanyF

Active Member
...minus the audio which is something of a problem...
MC-TV Converter is built around RemuxTool, which I use to convert wtv files. RemuxTool is supposed to automatically select the audio track with the highest bitrate but often doesn't - it selects the audio-description track. If you get no audio in the ts file, go back and re-convert but manually select the other audio track.

The AMD 11.6 drivers also caused pixellation for me on the BBC HD channels - strangely not on ITV1 or Ch4 for some reason :confused:
 

drathan

Standard Member
The 6450 has arrived and been installed, and all is now working fine. I am sticking with the 11.4 Catalyst drivers, and I don't get the blocking that is shown in the pic linked above (I did with 11.5).

All HD channels now come through quite happily and smoothly. The only problem now is the very occasional break up, but I think that is signal related rather than hardware.

I'd call this solved.
 

colin m

Active Member
Hi,

I've just popped a BGT3620 tuner into my HTPC (same mobo as above - GA-MA78GM-S2H - but an Athlon 5050e chip) and am getting very stuttery HD. I've been looking at resource utilisation during the problem - which as above see is mainly during live broadcasts, not on recorded hi def - and neither the CPU, disk I/O or memory are being stressed.

I've upgraded all my drivers, including the AMD catalyst drivers to the latest versions. I run the display at 720p as I already know it can't drive 1080i.

So all I can think of is the onboard HD3200 GPU can't handle it. Is it worth upgrading to a ATI 6450? Do you think it will fix the problem as it did with drathan? I'm just a bit reticent as several ppl here have said it's definitely a software problem.

thanks
Colin
 

colin m

Active Member
Hi AMc - I put the 11.4 catalyst drivers on and thought the problem had gone...unfortunately after about 5 mins of watching BBC HD, the stutter comes back. This seems happens now after every reboot - perfect for a whole, then the stutter returns.
That would lead me to think something is running after 5 mins, but I can't see anything starting, and as before plenty of CPU & memory available.

Bossworld - how do you change deinterlacing mode? Within the catalyst control panel?

Thanks for your help

Colin
 

Bossworld

Active Member
Bossworld - how do you change deinterlacing mode? Within the catalyst control panel?

Thanks for your help

Colin

Correct, I'm at work at the moment but within there (video settings I think) it'll be set to some kind of automatic mode. Clear the checkbox then drop it down one on the slider to the left.

Think you'll end up with motion adaptive rather than vector adaptive.
See my thread here: http://www.avforums.com/forums/home-entertainment-pcs/1622831-freeview-hd-stutter-ati-problem.html

The quality isn't as good as my old GT 220 but least I'm not running at high temps now.
 
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colin m

Active Member
Quick update - I tried messing with the deinterlacing & other display settings and I thought I'd cracked it, but the Freeview HD stuttering came back.

So...I've just put a Gigabyte HD 6450 card in - and hey presto! it's perfect. I can now scale up to 1080i, which I couldn't before. The problem has gone with both the 11.4 and 12.4 Catalyst drivers too.

Couple of other queries - I went for the Gigabyte card as it said that it's crossfire compatible with the internal HD3200, but there's nothing in the Catalyst drivers (either 11.4 or 12.4) that even mentions crossfire. Has this feature been retired by ATI or am I missing something?

Secondly - Dolby Digital in Freeview HD - I've seen some threads on this but has anyone found a solution to stop 2 channel PCM sound going to the receiver over HDMI? I get 5.1 when playing a DVD back through Media Browser, but watching BBC HD, for example, doesn't get translated.....I know they don't transmit in this format, but is there a way of encoding it?

Thanks
 

Sandy B Ridge

Active Member
Secondly - Dolby Digital in Freeview HD - I've seen some threads on this but has anyone found a solution to stop 2 channel PCM sound going to the receiver over HDMI? I get 5.1 when playing a DVD back through Media Browser, but watching BBC HD, for example, doesn't get translated.....I know they don't transmit in this format, but is there a way of encoding it?

Freeview HD (not freesat) has 2 audio streams - the 2Ch PCM and a 5.1Ch HE-AAC (not Dolby). It is problematic in 7MC. Different player filters are needed. deleted member was fettling with this in 7MC and may have a working system for it.

Some of the more configurable players can use LAV filters (to decode the HE-AAC->PCM) and Reclock (to maintain number of channels and bypass the windows mixer). You'll need to connect via HDMI since SPDIF/Optical can't do >2Ch PCM. HDMI has no problem with 5.1Ch PCM once it is decoded.

SBR
 
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wyerd

Active Member
Apologies for hijacking this thread, but I have a similar problem with a new Blackgold BGT3620 DVB-T/T2 dual tuner card.

I have been running a TBS 6981 Dual DVB-S/S2 for the last year which I successfully receive HD signals for BBC1 HD, BBC HD, ITV HD & C4 HD, with no picture judder. However, I do get picture judder with these HD channels using the BGT3620. The video card is an AMD HD5450 using Windows 7 Media Center. Would upgrading the video card to AMD HD6450 stop the judder or is being caused by something else?

Thanks for any advice.
 

colin m

Active Member
Yes, I'd say that you have exactly the same problem I had, and replacing the GPU was the answer. I'm still running with 2GB RAM and an Athlon 5050e using WMC7, and I didn't even change the power supply - the HD6450 said it needed 500W, but I'm running it ok with 350W.
 

STdrez625

Banned
I would say that the 6450, or any card that doesnt need a seperate power input, will use at most 75w as that is all it is allowed to use from the Pcie slot. 500w is most def Overkill even 350w, with all (your) low power parts is easily good enough.
Very little differene between Hd5450 and HD6450 ?? :confused:
 
D

Deleted member 39241

Guest
Freeview HD (not freesat) has 2 audio streams - the 2Ch PCM and a 5.1Ch HE-AAC (not Dolby). It is problematic in 7MC. Different player filters are needed. was fettling with this in 7MC and may have a working system for it.
SBR

I never got it working in 7MC, it was one of the main reasons I switched to MediaPortal. It is working in MediaPortal though :thumbsup:

Details of how to set it up are in Robbo100's MediaPortal set up guide.
 
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Bossworld

Active Member
I think I've now got the same problem after moving back to my GT220. Either never noticed at the time or something's changed, but it's been very noticeable during the Euros.

It's fine on SD channels. Did some troubleshooting, tried various drivers but it keeps doing a tiny micro stutter. Tried streaming it through 7MC Extender on the 360 and it's silky smooth so has to be something to do with the graphics card or driver :S

Was yours full on stutter or tiny microstuter (e.g. every 5 seconds, slight hesitation)
 

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