Video Quality Degrading

[Buu]

Yeah, it's me again, with the same problem as ages ago, if anyone remembers: https://forum.videohelp.com/threads/318383-MKV-Video-Encoded-In-H264-Suddenly-Worse-Quality

First off, sorry if this is posted in the wrong forum, I felt that it had a better place here, feel free to move it though.

Again, I'd like to tackle this problem as it's still bugging me and I'd love to finally clear this topic up.

To get started, I know that video quality should not degrade at all. I'm only watching and moving the videos around, doing nothing else with them. Yet, they seem to degrade in quality.

I'll make an example: I download an anime, 720p bluray quality and everything is sharp. A few days later, I notice that the video suddenly became a bit more pixel-y, colors are a bit darker, sorta like a JPG picture. Especially black outlines which used to be very sharp are suddenly blurry and more pixel-y.

Please don't come with "video quality doesn't degrade just like that" etc., I know for certain that all of my videos are starting to get worse in quality. And I have no idea why this happens. Is it my laptop having some sort of issue? Is there something that's faulty that could cause this degradation to happen? Currently I'm using MPC-HC as my media payer and the Combined Community Codec Pack, as suggested by pretty much everyone who tried to help me.

This is starting to drive me nuts. I appreciate every help I can get.

[t0nee1]

I'll make an example: I download an anime, 720p bluray quality and everything is sharp. A few days later, I notice that the video suddenly became a bit more pixel-y, colors are a bit darker, sorta like a JPG picture. Especially black outlines which used to be very sharp are suddenly blurry and more pixel-y.
This is starting to drive me nuts. I appreciate every help I can get.

Too much tequila maybe?..Really video DOES not degrade by just "moving" it around from folder to folder..
Maybe your video card and or settings..Did you not see the "Warning" when installing that codec pack..

[Buu]

No really, I know that video quality doesn't degrade just by moving it around, yet it does. D:

Anyway, since last time I reinstalled my OS, I only installed the CCCP, no other codec packs or similar as it got its job done just perfectly. And directly after downloading the video, it had awesome quality, a few days later it became more pixel-y. And I didn't even install anything new between that time.

I'm trying to capture a few screenshots next time I download a video (no idea why I didn't do that earlier) so I can show what I exactly mean. :\

[jagabo]

Files do not degrade. If you are really seeing a problem it is because your hard drive is developing bad blocks (and if this is the case your computer will likely start crashing soon). Or you have changed something about your system and the files, though unchanged, are playing back with different, and inferior, decoders or display drivers. Or Hollywood has infected your system with a worm that searches out all your videos an is screwing them up.

[filmboss80]

By any chance, would YouTube be the source of your anime videos? Sometimes they play back high quality version of the video, but what you end up downloading is a lower-quality .flv file. That's the only possible explanation I can think of.

Currently I'm using MPC-HC as my media payer and the Combined Community Codec Pack, as suggested by pretty much everyone who tried to help me.

Was the CCCP suggestion made by someone in this forum? I can see where the "everyone" of VideoHelp would have no problem suggesting MPC-HC, but the majority of us would not be such saboteurs as to recommend a codec pack.

[TimA-C]

A few thoughts about your problem;-

1. You say you're viewing on a laptop, are you always watching while running off the mains or are you sometimes watching whilst running off battery? If the second, are any of the power saving features causing the changes you see? (Brightness, CPU speed, etc.)

2. Are the lighting conditions always the same when you're viewing? Ambient light can make a HUGE difference to picture quality.

3. What about screen angle? Depending upon the type and quality of your screen, small changes in viewing angle can make quite big differences in picture quality.

4. You. Do you find the picture quality looks worse at the end of a working day when maybe your eyes are tired? Are you susceptable to low blood sugar if you miss or delay a meal?

[jagabo]

Of course, there's a simple test you can run. Get an MD5 checksum on the video right after downloading. Check the MD5 checksum some days later. If the checksums aren't identical the file has changed. Or download the file again and compare.

[Buu]

By any chance, would YouTube be the source of your anime videos? Sometimes they play back high quality version of the video, but what you end up downloading is a lower-quality .flv file. That's the only possible explanation I can think of.

No, I always download over IRC from bots. Most videos are .mkv files whereas a few are .avi or .mp4.

Was the CCCP suggestion made by someone in this forum? I can see where the "everyone" of VideoHelp would have no problem suggesting MPC-HC, but the majority of us would not be such saboteurs as to recommend a codec pack.

Not here on the forums. So far I only talked this problem through in-depth with various people on IRC (except for that one thread here).

A few thoughts about your problem;-

1. You say you're viewing on a laptop, are you always watching while running off the mains or are you sometimes watching whilst running off battery? If the second, are any of the power saving features causing the changes you see? (Brightness, CPU speed, etc.)

2. Are the lighting conditions always the same when you're viewing? Ambient light can make a HUGE difference to picture quality.

3. What about screen angle? Depending upon the type and quality of your screen, small changes in viewing angle can make quite big differences in picture quality.

4. You. Do you find the picture quality looks worse at the end of a working day when maybe your eyes are tired? Are you susceptable to low blood sugar if you miss or delay a meal?

1. I'm always running of the mains.

2. Yes.

3. Screen angle is also always the same. It doesn't make much difference to me when tilting the screen either.

4. No and no.

Slowly I'm starting to think if I'm not only paranoid or something. XD

Of course, there's a simple test you can run. Get an MD5 checksum on the video right after downloading. Check the MD5 checksum some days later. If the checksums aren't identical the file has changed.

Alright, I will do that. Thanks for the info!

[Alexstarfire]

I actually know EXACTLY what the OP is talking about. I had that happen to me before. It was extraordinarily noticeable. I've got no idea how to fix it though since all I had to do was restart my computer. You should try a different media player, like WMP or the regular MPC. Just something that uses the DirectShow Filters. If you still have quality issues while playing the video then it's probably the video file and you can try what jagabo says. Or just download a new video. Doubt 2 would have the exact same problems.

Either way, I'd recommend uninstalling CCCP. The only thing you really need from it is Haali Media Splitter and you can download that separately.

[TimA-C]

Graphics chip overheating? It's not an HP or Compaq laptop is it?

[Buu]

@Alexstarfire: Unfortunately, there's not really a change between those players. It still looks the same. Redownloading the video is also a funny story, because the newly downloaded video looks just exactly like the old one.

@TimA-C: No, it isn't.

I'm going to check out a few videos on my parents laptop once I get to it (can't believe I didn't try that either) to check if it looks right on theirs. I refuse to believe that my laptop could have ruined my videos in any way. :P

[jagabo]

You either have a playback problem or the video file was always bad.

In MPC go to View -> Options -> Playback -> Output and try the different DirectShow Video output devices. You have to exit MPC and restart it for the change to take effect. See if any of them look better or worse.

[Alexstarfire]

Sure it's not your video drivers or something?

[Nelson37]

Have you tried playback after a cold boot? How about a DVD disk? Download a video to a USB stick, or burn to a CD or DVD. Test immediately, then after a few days.

Try another self-contained player like VLC. Download, play, reboot, disconnect from internet, test play, store off the hard drive, test after clean boot, test on another PC.

SEPERATE the component pieces. ISOLATE and IDENTIFY.

Overheating, software playback issue from conflicts, failing hard drive.

[Buu]

Alright, I tested out a few videos on my parents laptop and there are small differences here and there. On theirs, some videos have brighter and clearer graphics opposed to my laptop while some videos remains just the same. Some of them look sharper, though that might be just the a tad smaller screen. In any case, the videos on their laptop look better then they do on mine, albeit there aren't too major changes. Unfortunately I couldn't make a direct comparison because for some reason, the printscreen feature on their XP seems to not work properly and therefore cannot save a proper image. :\

Now to get to the replies you guys made:

@jagabo: I've found that the "VMR9 (renderless)" option works best as the colors are more vibrant and the image overall isn't that pixel-y.

SEPERATE the component pieces. ISOLATE and IDENTIFY.

Uhm... what exactly does this part mean? I'm not that good with computer terms so excuse me for my lack of understanding. :P

[jagabo]

@jagabo: I've found that the "VMR9 (renderless)" option works best as the colors are more vibrant

That's just a matter of video proc amp settings. Get a calibration video and use your graphics card's setup applet to adjust the video contrast, brightness, colors, etc. Note the Desktop and Video have different settings.

and the image overall isn't that pixel-y.

That may be the choice of scaling algorithms. You can often adjust those in the player and/or in the graphics card's setup applet. Note the VMR7/9 Resizer option in the same dialog where you pick the output device in MPC. Often when you install updated graphics drivers these settings get reset or screwed up.

SEPERATE the component pieces. ISOLATE and IDENTIFY.

Uhm... what exactly does this part mean? I'm not that good with computer terms so excuse me for my lack of understanding. :P

Standard diagnostic procedure. Break your problem down into its individual components. Test each in isolation. For playing video you have a file reader, a file splitter, a decoder, maybe a colorspace converter, and finally a rendering device. Your problem is most likely in the decoder, colorspace converter, or renderer. You can't really test each of those in isolation. But what you can do is try different combinations using a tool like GraphEdit, or a system filter editor like Filmerit, DirectShow Filter Manager, or MPC's filter options.

Also note that MPC will let you see what filters it is using while playing a video. Right click on the window and hover over Filters. You can select any of the filters to set any options.

[Nelson37]

Cold boot eliminates other running software.

Leaving the PC off for a while beforehand eliminates overheating.

DVD disk eliminates file changing possibilities.

Download to USB eliminates your hard drive.

Using VLC eliminates your codec installation.

Using another PC eliminates your PC altogether.

Disconnecting from the Internet eliminates other possible file sources.

You have described playback of "files" on another PC. Unfortunately, you have described a situation wherein "files" apparently change, so that the term "files" becomes nearly useless. "Files with original playback quality" OR "files with apparently degraded playback" must be specified for comparison information to be at all useful.

[Nelson37]

Apparently, even after posting twice about it, this problem is not important enough to the OP to bother to reply to.

When he posts about it again, I will take the same attitude.

[TimA-C]

Apparently, even after posting twice about it, this problem is not important enough to the OP to bother to reply to.

When he posts about it again, I will take the same attitude.

It's only been 2 days since the OP last posted, maybe he's having to work or talk to the other half or something?

If his problem is genuine, and he really has been able to discount all the suggestions that have been offered here (just saying "no it isn't." doesn't really count in my book) then I reckon he's either being targetted by a secret government organisation, aliens, the future, or his laptop is being haunted by a dead quantum physicist! I'd have a little more time for him if he'd report back after following jagabo's suggestion of generating a checksum and then comparing that checksum after the apparent degradation has happened again, or your suggestion for playing off a DVD which would dramatically reduce the chance of file corruption and effectively take that out of the equation.

Does anyone know if he lives near either Sellafield or Chernobyl?

[Buu]

Apparently, even after posting twice about it, this problem is not important enough to the OP to bother to reply to.

When he posts about it again, I will take the same attitude.

Bwahahaha. Just wow. You know, I really appreciate your help but there are also other things in my life besides computer related stuff. Thank you very much. But yeah, go ahead and "take the same attitude" if you wish to do so. I don't really care.

Anyway, since those few days ago I downloaded a video for testing and now, nothing has changed. Nor did the quality neither did the checksum.

I'll try out the suggestions with the USB and DVD soon.

[Buu]

Alright, I've got some updates, if anyone still cares, that is.

I've burned some episodes on DVDs and - just as I expected - the same thing happened after a while. The clear videos became more rough and pixelated. Now the funny thing is, I can't rewrite the DVD so I would assume that there's like nothing that *should* be able to change the DVDs contents (unless I'm mistaken on this one). Unfortunately, I forgot to take some example screenshots yet again (I've got two screenies from different episodes, which are on another DVD though, but I'll get to those soon anyway) so I can make a concrete comparison. Btw, saving the stuff on USB and external HDD gave me the same results.

Now what's really weird, is following: I put in the DVD on day A, watch a few episodes, take it out and on day B, it suddenly has a degraded quality. I can't think of any reason how that's supposed to happen. Bummer that I forgot to do an MD5 checksum aswell. >_<

But yeah, I've already got screenshots of the "good quality" from the episodes on the other DVDs so I might aswell compare the checksums too. We'll see how it's going to turn out.

I'm really starting to believe that my laptop is at fault here. I mean, all those videos saved on USB, an external harddrive and even burned on a DVD can't possibly all be damaged. But alright, let's wait a few more days and by then, I'll hopefully have some more concrete details regarding this issue.

Also, I do care about this "problem", it's just that I also do other things and I'm generally the slacking off type of guy. Please don't assume that I don't care about this at all because I won't post for a few days. I appreciate all your help and I'm trying to follow your suggestions as good as I can to pinpoint what exactly is wrong here. Just give me some time.

[Nelson37]

If you still have the same files, burn a second DVD. Verify good or degraded playback.

Also, test each DVD in a standalone player. Create one that plays correctly in a standalone player. Test again after a few days, using ONLY the standalone player.

Odds are going up that there is something related to the laptop's video playback hardware.

[TimA-C]

Well, I think you've confirmed what we all thought, that it wasn't the files degrading but either hardware - possibly temperature related - or wetware (i.e. You) - possibly alcohol related!

Hope you manage to finally track it down.

[Buu]

Haha, I haven't had alcohol in a long time so let's rule out that possibility. XD

So, I got the screenshot and the MD5 checksum ready, now it's just a matter of time until that "degradation" takes effect and then we'll see.

@Nelson37: Unfortunately, these files are in .mkv format and playing them with a standalone DVD player or any other device would be impossible. I'll definitely get the file onto another DVD though (possibly redownload the file) and test again.

One more thing I might shall mention: Back then, when I started experiencing this problem (before, I haven't even really downloaded videos so I can't say for sure that this is an exceptional issue), I redownloaded a few copies of the degraded files and they did definitely have the same quality as the degraded ones, rather than being "fresh", so to speak. And as I see it, this most definitely should not be the case. Downloading the first time, having good quality, at one point suddenly degrading, re-downloading the videos and remaining the same doesn't seem to make any sense. It's like my laptop "remembers" these files and plays them in a worse quality on purpose to piss me off. And reinstalling my OS didn't help whatsoever...

I'm almost sure it's my laptop being at fault here, all the points I have mentioned speak against the files being the problem. (But why would the videos on other computers remain the same worse quality when transfering them then?) I think I'm going to make another little test tomorrow.

Anyway, let's wait and see how the situation is going to turn out. I'm suprised though that a Google search didn't turn up another topic somewhere with someone else having the same or similar issue... *shakes fist*

[Buu]

Sorry for double posting but I got some updates.

I decided to approach a slightly different method to reproduce the degradation and it seemed to work, so I was able to take two shots, one from the worse video and one from the better one. Unfortunately the video is a quite low quality video to begin with so the changes might only be noticable when comparing side by side (or open them in two different tabs and toggle between them):

http://i52.tinypic.com/2duid8n.jpg < Good
http://i52.tinypic.com/x360ww.jpg < Bad

It wouldn't annoy me that much if it were only for that little bit of degradation. But when it comes to the higher quality videos (which I'll try to get a shot from soon), it's really noticeable.

Anyway, now here comes the weird part. This is what I did: At first I plugged in my external hard drive and made a screenshot from a video (see the image labeled as "Bad"). Then, I downloaded the exact same file on another laptop and viewed it there. The quality was better than from the file viewed on my laptop. I made a screenshot from it to compare, put the video on an USB stick and plugged it into my laptop. I viewed the video here (keep in mind it's still the freshly downloaded one) and the quality remained the same good one. Then I plugged the USB out and my HDD back in. Viewed the other video (the "bad" one in this case) and - to my surprise - it remained in the same "good" quality.

Alright, I did an MD5 checksum test on both files and they matched each other perfectly. So far, so good. Plugged the HDD out, plugged it ito the other laptop and took a peek at a few videos to see if any other ones "magically" turned into their old form (lol). Sadly they didn't. Plugged the HDD out again, back into my laptop, opened the video file (the one I am talking about) and it turned back into the same bad quality again!

Now I'm at a loss of words. The videos didn't seem to have any changes between them whatsoever, nor in checksum, neither in file size. What should I think now? Does my laptop remember the viewed videos and play them in a bad quality on purpose or what? No seriously, this whole thing doesn't make any sense...

[TimA-C]

Buu, just to let you know that quite a few Bluray players and network enabled PVRs can handle MKV files these days.

[lordsmurf]

The difference between your "good" and "bad" is not due to the files. There are a few small blocks that are indicative of file system issues. That is to say, a bad hard drive. OR if not hard drive, then an issue with buffering of some sort, whether it's RAM or otherwise. Anyway, it's hardware related.

The files are not "bad" but simply displaying badly when played sometimes.

I get similar issues trying to play 720p video on an older P4 system. It's a CPU/buffer/RAM issue.

USB drives can be an issue, as USB runs through CPU, and is slower access.

[jagabo]

A bad hard drive or DVD would be obvious. There would be CRC errors and the drive/OS would make several retries. This would make an obvious head calibration and seek noise (from the drive) and cause a pause in the playback. If many of your video files were getting errors so would all your other files and Windows would soon crash. You can rule out file corruption.

When h.264 decoders are running out of time (ie, they can't decode the video at the indicated frame rate) they start skipping the deblocking option. That causes more visible macroblock artifacts. This could also be an issue with what decoder is being used -- GPU (DXVA) vs. software, or what output render is being used (Video Overlay, VMR7, VMR9, EVR... they all have different amounts of post processing, proc amp controls, scaling algorithms, etc).

[lordsmurf]

Small drive errors would often go unnoticed, but video uses large amounts of continuous space.
So I'd not eliminate it just yet.

[Buu]

So basically I can rule out the possibility that the video files are at fault but it's my laptop that's causing all these problems? Did I understand that correctly?

What I still don't get then is why each video I download starts out good and once it became "bad", it remains all the time like that. And viewing them on our other laptop doesn't make any difference... I'm not a too tech-savvy kind of person, so excuse me if I'm saying anything stupid.

Well, if I can put the all the blame onto my laptop, then that's great. I ought to get a new one since this has been acting up continuously anyway...

If there's any other info about my laptop you guys think might be important related to this, then please don't hesitate to ask me for it.

@TimA-C: I do have a Blu-Ray player but regretfully, it doesn't support MKV files. I already tried to get those running on it but it seems to only allow AVI videos.