HTPC Codec help appreciated

Freakitchen

Freakitchen

Freakitchen

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Will try and keep this short and simple, hope the solution is too!

I have an HTPC system, running an Athlon 4400+ with 2GB of RAM and an ATI 3450 Video card, with Vista Ultimate. After messing with codecs for ages and ages, I've tried to keep things simple on this install. Media Center uses the Microsoft MPEG-2 codec for DVDs and TV, and that's fine. I've installed the XVid codec for the .avi Xvids I've made myself for archiving recordings - also fine. It's just HD giving me the problem, and I'm hoping it's a software rather than hardware issue.

Basically, to play back the .mkv files I have, I've tried both FFDshow and CoreAVC, both of which seem to have the same 'jerkiness' on horizontal pans every half second or so. Hopefully someone will know what I mean here, the picture pauses for a split second. Not noticeable in fast-moving scenes, but on slow camera movements, it annoys me.

I'm not sure what more I can do to solve this. Is there another codec I can try? Is it that the video card isn't up to the job? What's confusing me more, is that I also have some HD contained in a .avi format, and these play back perfectly, which leads me to believe that my video card is okay, but I honestly don't know what's 'behind' the .mkv and .avi containers in this case.

Cheers for any help
 
Your video card won't be helping on the MKV files, or AVI, they'll be software only. (I think)

If I were you I'd un-install all of the codecs you have at the moment and then install the latest version of FFDshow tryout and Haali Media Splitter.

Are you using a 64bit version of Vista?
 
Furton said:
Your video card won't be helping on the MKV files, or AVI, they'll be software only. (I think)

If I were you I'd un-install all of the codecs you have at the moment and then install the latest version of FFDshow tryout and Haali Media Splitter.

Are you using a 64bit version of Vista?
Click to expand...

Having searched a few forum posts, I think you're right with the video acceleration (or lack thereof). If that's the case, I'm even more confused as to why the video refuses to play back smoothly - would have thought a dual core processor was more than up to the task!

My initial codec install on that system was Haali Media Splitter and FFDShow (the standard version). Is 'tryout' a beta version? Before posting I was actually tempted to ditch FFDShow - it produced the same jerky playback of standard xvid files. The codec from Xvid.org plays them back perfectly.

I'm running 32-bit Vista.
 
I think this "jerkiness" might have something to do with frame rates.

- Whats frequency are you running your HTPC at?
- What TV are you using and is it 720p/1080p/24Hz?
- What input, HDMI, DVI?
- What resolution you running the HTPC at?

This so called jerkiness can occur when running at the wrong frequency. HD is approx 24Hz (23.9...frames a second). Most new TV's support this. I have a feeling that your running at 50/60Hz which is why you get the jerkiness. Try setting it to 24Hz on your TV or in the settings in your GPU control panel
 
photoshop said:
I think this "jerkiness" might have something to do with frame rates.

- Whats frequency are you running your HTPC at?
- What TV are you using and is it 720p/1080p/24Hz?
- What input, HDMI, DVI?
- What resolution you running the HTPC at?

This so called jerkiness can occur when running at the wrong frequency. HD is approx 24Hz (23.9...frames a second). Most new TV's support this. I have a feeling that your running at 50/60Hz which is why you get the jerkiness. Try setting it to 24Hz on your TV or in the settings in your GPU control panel
Click to expand...

Interesting thought, my knowlege of frequencies is limited. My HTPC is connected to a 46" Samsung LCD TV (LE46A559P4F), via a DVI - HDMI cable. It's currently running at 1920x1080 @ 50Hz. I didn't realise the frequency could be set correctly to anything other than 50-60Hz. Is there any way of finding out whether my TV supports 24Hz? My understanding is that selecting unsupported frequencies can damage TVs, and it was pretty expensive!

It might be worth noting that I can play back the same .mkv files on my own PC - more powerful with a Quad Core and X1950Pro - without the stuttering, even though both standard monitors are set to 60Hz. Does that info make any difference?
 
Freakitchen said:
Interesting thought, my knowlege of frequencies is limited. My HTPC is connected to a 46" Samsung LCD TV (LE46A559P4F), via a DVI - HDMI cable. It's currently running at 1920x1080 @ 50Hz. I didn't realise the frequency could be set correctly to anything other than 50-60Hz. Is there any way of finding out whether my TV supports 24Hz? My understanding is that selecting unsupported frequencies can damage TVs, and it was pretty expensive!

It might be worth noting that I can play back the same .mkv files on my own PC - more powerful with a Quad Core and X1950Pro - without the stuttering, even though both standard monitors are set to 60Hz. Does that info make any difference?
Click to expand...


I have a feeling it my have something to do with your DVI to HDMI dongle. If its not a good quality one then it needs to be binned! I've come across this issue before with people using DVI to HDMI dongles.

Im not sure (well, i dont think) your LCD supports 24Hz playback.

Try this: Run your HTPC at 1920x1080 @ 60Hz and see if that resolves the problem.
If that doesnt work then try getting a better quality DVi to HDMI Dongle.

Your HTPC spec is more than capable of playing back 1080p FULL HD content!
 
Holy thread revival and all that....

A few weeks ago I FINALLY got round to changing the cable as photoshop suggested. I was putting it off because of the cable-tidying work I'd have to undo in the process. Anyway, long story short, with the lack of a decent replacement DVI - HDMI cable, I tried the system with a VGA cable, the result being perfectly smooth playback! Obviously, contrary to my previous thoughts, all digital cables are NOT made equal!

The problem is now that I don't want to stick with the VGA cable - the picture is fundementally inferior to the digital connection. Black levels are frankly terrible, and there's a washed out appearance to everything even after turning on full video vibrancy in the ATI options and messing about with the TV brightness/contrast settings.

So, would a GOOD quality digital cable fix my problems? How much is it worth paying for one of these? Any recommendations? I will say that using a DVI - HDMI dongle, and a standard HDMI cable isn't really an option, as there's no space at the rear of the computer for one. I'm already struggling with the length of a standard DVI plug.

Cheers guys.
 
Checkout Plexus cables. They always seem reasonably priced but reasonably made well made, infact I'm of a strong opinion they're actually just one of the large OEM manus that the others used, bundled under a cheap brand. Should be able to get a few m digi cable from them for less than a tenner :)

Sorry can't link the site that sells them as its a large OcUK competitor. Belkin cables are also pretty well made but expensive.
 
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Alexrose1uk said:
Checkout Plexus cables. They always seem reasonably priced but reasonably made well made, infact I'm of a strong opinion they're actually just one of the large OEM manus that the others used, bundled under a cheap brand. Should be able to get a few m digi cable from them for less than a tenner :)

Sorry can't link the site that sells them as its a large OcUK competitor. Belkin cables are also pretty well made but expensive.
Click to expand...

I'd have to check, but it's quite possible that the current cable I'm using is a Plexus. Looking at the site in question, it seems they're the brand of choice at the lower end. I guess it's quite possible that the one I've got is just a dodgy one, but I'd be much happier spending £15 on a Belkin cable, if they're guaranteed to be high quality.

Incidentally, anyone know the reason why my current cable is causing the stuttering?
 
Thread bump. Finally getting round to sorting this issue. The stage I'm at now is that a VGA cable provides smooth playback of all video types, but the picture is washed out - black levels are especially rubbish. The picture with a DVI - HDMI cable is much more vivid and to a standard I'm happy with, but there's a constant stuttering on the playback - especially with H.264 HD and Xvid files (not so much with MPEG, but it's still there). Have tried 2 different, but identical cheapo cables, same issue with both.

My question is - should I now be looking at a high quality DVI - HDMI cable, in the hope that it'll fix the problem? If so, how much should I be looking to spend, and any particular brands to look out for? I won't post the website I'm looking at, but they stock 'Profigold' cables at around £25 for 2m, and IXOS & 'Wireworld' cables that are double that for the same length. This seems extortionate to me, but I'm willing to pay either if it'll definitely solve my problem.

Anyone with any experience of this type of thing? What I don't understand is why I don't have these issues with my own computer, connected to a Samsung 22" screen, using the bundled DVI - DVI cable. It's almost the same resolution as the 46" TV I'm using....does physical picture size have anything to do with it?

Cheers
 
Monitors are made to support almost all frequencies so it wont jump.
ANY digital cable will cause jerkyness on your TV. Digital will mean exactly the same as source when playing a movie so using a digital cable will mean your movies will be jerky. I have the 37 inch version of your TV & there is no 24p support.
I will hopefully be changing my TV in the next 6 months
 
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