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HTPC Stuttering when playing MKV's

dumbmayhem

Active Member
Having a little trouble with one of the files I have just tried to play. The file is a mkv file and when I try to view it in Media Centre the file began stuttering every 5 seconds. This was frustrating the life out of me so started restarting, pulling out usb's etc and changing things to no avail.

Opened the file in VLC and the stuttering began to stop however, juddering *i think is what its called) began to happen and the video would stop and then go really fast to catch up with the audio.

I then opened the file in Media Player and the same thing happened that occurred with Media Centre. However; when trying this I noticed that no stuttering occurred when the file was opened in a window and only started doing this when it was full screen.

The file is a 23.976 fps and when I changed my resolution down to 25fps it made no difference however; I wasn't 100% sure what I was doing messing with the resolution to be compatible with fps.

I've tried playing HD .avi files and they were fine and no issues with stuttering etc and another mkv movie I had which was also 23.975 fps was fine. Does this lean towards a bad file or a bad sector in the HD?

Does anyone have any ideas?

HTPC straight to TV via HDMI
Running at 60hz
Windows 7
Using Win7codecs
 

pistacja

Banned
I have both media player classic and vlc on my mpc. I don't know what the best codec is hence why I have both. Hope this helps.
 

simplicity96

Distinguished Member
They are programs not codecs. Codecs are things like ffdshow and coreavc which decode the h.264 streams more efficiently.

Also if you have a powerful enough graphics you can use the graphics chip to take the brunt of the decoding of video streams which helps.

You will first need to be more specific on filesize and bitrates you are trying to playback that are causing the stuttering.
 

pistacja

Banned
simplicity96 said:
They are programs not codecs. Codecs are things like ffdshow and coreavc which decode the h.264 streams more efficiently.

Also if you have a powerful enough graphics you can use the graphics chip to take the brunt of the decoding of video streams which helps.

You will first need to be more specific on filesize and bitrates you are trying to playback that are causing the stuttering.

That's what I meant. I don't know what codecs each program use. Hence why I use both vlc and media player classic.
 

simplicity96

Distinguished Member
Vlc has its own built in codec set and mpc uses external codecs giving the ability to use any you choose. Vlc is good in it plays nearly everything thrown at it but the playback quality isn't always the best. Mpc is a very versatile front end for video playback and combined with the afore mentioned codecs (one or the other) should help with higher bitrate playback.

I believe vlc has the ffdshow codec for high def playback but doesn't seem to perform as well in that as it does being used as a external codec.
 

dumbmayhem

Active Member
Hardware in the PC is not top of the range and was built on a budget to only play 720p files.

PC consists of:
Asus AMD E35M1-M PRO (AMD Hudson M1) DDR3 MicroATX Motherboard
OCZ Vertex 2 50GB 2.5" SATA-II Solid State Hard Drive
Kingston HyperX Blu 4GB (2x2GB) DDR3 PC3-10666C9 1333MHz Dual Channel Kit (KHX1333C9D3B1K2/4G)
Playing files on an external 2TB HD.

Note: Last night I did move the file onto my SSD drive to see if it was a bad sector or something and the file did the same things. I have now tried the file on my old PC at my parents (quad core) and the file played smoothly with no issues.

File in question:
scaled.php
 

imilne

Active Member
The file is a 23.976 fps and when I changed my resolution down to 25fps it made no difference

There's your problem right there.

If the file is encoded at 23.976 fps then you need to set your video card to output at 23.976 Hz, and have a display that supports 24p. On AMD/ATI cards this is usually listed as just "23". Note that 23.976 and 24.000 are not the same, so you'll still see slight stuttering if you can't match the rate exactly.

You could also use ReClock to adapt the video on the fly and play it back at 25 fps which would then perfectly match a 50 Hz output. This is how most PAL-encoded movies are handled (with a 4% speedup).
 

dumbmayhem

Active Member
OK fair enough. I've never had to do that in the past with any of my films/episodes but I'll look into that. Why all of a sudden though would this have happened. It wasn't happening in any files I've watched before and after it happened the other night, I tried watching other episodes of the same series that I have already watched and the same thing was happening with those - which didn't occur the week before when they were first viewed.

P.S - I have a NVidia Card and the lowest res I've been seeing is 25hz.
 

imilne

Active Member
Why all of a sudden though would this have happened.

Only you can probably answer that. Maybe you didn't notice with the other files? Maybe something else has changed in your setup?

You can get 23.976 fps content from several sources, eg ripping blu-rays or NTSC DVDs. If that's where these files came from then they really shouldn't be stuttering if ripped correctly. If however, they came from the internet at large (and your blanked out filename hints at that) then you can't be sure that they were encoded properly in the first place. If the stutter is *in* the actual video, then you're SOL.

P.S - I have a NVidia Card and the lowest res I've been seeing is 25hz.

It may be detecting what your display is capable of automatically then. Either set it to 60 Hz and live with slight 3:2 pulldown stutter, or try ReClock with its 4% speed up and 50 Hz which should give 100% smooth video. It can be a little fiddly to get right though.
 

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