Matroska video files (.mkv) questions

[GreeN!X]

I've tried searching this up on google but it seems that this file haven't really caught on since there's isn't much info available yet. Either that or I was just using the wrong keywords. So, I'm here to ask some stuff from you guys.

I have observed from the mkv files I've downloaded that when the video resolution exceeds my monitor's resolution, it would lag and pixelate a lot (with pink and green colors). Though playing it again will lessen the effect, it still is there. The subtitles and the sound works file though. The lag and pixelation is absolutely non-existent (or barely visible) with low quality videos though (720p below) so I was wondering, Why is this happening only to mkv videos with higher quality? Is this because of how mkv handles the files contained in it? or is it because of the software I use to play the mkv file? (VLC btw)

I'm hoping someone here knows enough of this file type to answer (or give clues) to why this issue happens to me.

 

[Velmarshal]

MKV are highly compressed video files and they are relatively low size comparing to the quality they dish out, hence why they are used by pirates commonly. While I do not know how exactly that format works, it probably has to do with its high compression ratio and that it affects how easily can it be resized, though that mostly depends on your CPU.

 

[GhostWolf]

MKV is actually a container, like AVI or any of the other similar formats.

About pixelation, there are two major reasons I can think of - a dying/slow/whatever HDD, or a really (depending on the resolution of course) weak GPU.

 

[GreeN!X]

Well I know it's a sort of container for files, but I just find it easier to refer to mkv as a video file rather than that.

Anyway, That was the first thing that popped into my head, but even though my PC is at least 9 or 10 years old, it doesn't really have any problems in displaying HQ video files. It plays 1080p video files easy with other file formats but easily pixelates and lags when the mkv file is 720p or above.

...that it affects how easily can it be resized, though that mostly depends on your CPU...

Yeah, I also thought about that. Since everything was displaying properly except the video, it has something to do with how the mkv file works (or how the program handles the files contained in it). And maybe since the video it contains has a larger resolution than my screen, it has to resize everything as I play (which also might explain why the pixelation is lessened when the file is played again).

I'm still not quite sure though (not even close actually). Perhaps it really is because of my GPU or CPU, but the fact that I can easily play other HD videos in other formats makes me doubt it. Maybe I can try it on a better PC tomorrow and see if I'll get the same result.

 

[GhostWolf]

I do remember MKV files generally being much slower on my previous hardware, maybe people use codecs with different ratios between compression and how easy it is to decompress?

Scaling shouldn't be a problem, because either your GPU and/or the monitor itself have hardware scalers (whatever the real word is) in them, the CPU shouldn't do any scaling.

 

[Radicool]

MKV are highly compressed video files and they are relatively low size comparing to the quality they dish out, hence why they are used by pirates commonly. While I do not know how exactly that format works, it probably has to do with its high compression ratio and that it affects how easily can it be resized, though that mostly depends on your CPU.

I don't think your right at all. MKV is a container. What video it contains it entirely up to the person who encoded the video, whether it is compressed or uncompressed. The MKV file does not dictate a compression ratio or anything like that. You can have a 100GB 60 minute MKV video, or a 700MB 60 minute MKV video.

I have observed from the mkv files I've downloaded that when the video resolution exceeds my monitor's resolution

I suppose I've never seen a FHD (1080p) resolution MKV file. I've only ever used regular HD (720p) MKV files. I've used other containers with FHD video which have lagged when I played it off the TV. It was too much for my laptop to display the video on my laptop and TV at the same time. I turned off the laptop display to allow it to focus on just the one display on the TV and the lag went away.

It may have something to do with the performance of your CPU. If your running off a laptop, turn your power plan to high performance (if it isn't already). If your playing the video off a TV, do what I have explained to see if the problem goes away.

In my case, the CPU handles video. I couldn't manage to get the GPU to handle the video. Depending on which GPU you have, there may be a way to override what handles the video. Could be worth looking into.

it would lag and pixelate a lot (with pink and green colors).

Sounds like a problem with the MKV files you have, or maybe your video player. Ensure VLC is updated. If that doesn't fix it, you could have faulty MKV files. Try getting different FHD MKV files from different sources. Maybe you downloaded a dodgy copy from the pirate bay. I normally check the comments to ensure a video is legit before downloading.

or is it because of the software I use to play the mkv file? (VLC btw)

If nothing I suggested works, you can always use a video editting program to downsize the resolution of the video to HD. This may resolve the problem.

 

[GreeN!X]

turn your power plan to high performance (if it isn't already)

Sorry but that's possible? I guess that could be possible with laptops but could that be done on my PC?

Sounds like a problem with the MKV files you have, or maybe your video player. Ensure VLC is updated. If that doesn't fix it, you could have faulty MKV files. Try getting different FHD MKV files from different sources.

This happens on any HD (or higher) from any sources so probably my VLC. I wonder though, my VLC is always updated since it's pretty much the only thing available in my PC so I that shouldn't be the case. I'll try it out on another player though.

Maybe you downloaded a dodgy copy from the pirate bay.

Well, I got it from a kind of exclusive site and the comments confirmed that it's pretty legit. So no problem there.

If nothing I suggested works, you can always use a video editting program to downsize the resolution of the video to HD. This may resolve the problem.

That'll be my last resort. It just takes so much work to edit so many episodes for a lazy bum like me.

 

[Radicool]

Sorry but that's possible? I guess that could be possible with laptops but could that be done on my PC?

I was referring to laptops. I haven't heard of power plans for PC's.

I'll try it out on another player though.

Let us know what happens. If this doesn't work, try playing these same MKV files on another computer and see what happens.

That'll be my last resort. It just takes so much work to edit so many episodes for a lazy bum like me.

Lol, couldn't agree with you any more. Just thought I'd mention it was a possibility.

 

[Velmarshal]

I was referring to laptops. I haven't heard of power plans for PC's.

Yup, PCs do have those.

 

[Dr Super Good]

Your computer is not powerful enough. Decoding video streams is one of the most demanding things average people make computers do.

Especially if you are not using Windows Vista (or 7/8) with a DX10 compliant (or better) video card. In this case it has to software decode which is a performance killer and why it is generally no longer a problem on modern computer systems to view even 1080p quality films.

Why do some movies at higher resolution work yet this does not? The answer is simply a different decoder. Some video sources are easier to decode than others and it is obvious the .mkv you are trying to play is such a demanding sequence.