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Another Pixel "flash" problem

 
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slanskye



Joined: 12 Jul 2004
Posts: 3
Location: San Antonio, TX

PostPosted: Wed 14 Jul 2004, 21:40    Post subject: Another Pixel "flash" problem Reply with quote

I have a similar problem described in this post http://dvd-hq.info/forum/viewtopic.php?t=105, except that I am using TMPGEnc 2.55. Also, my "flash" or "glitter" does not always happen on the same frames, even when encoding several time with the same settings.

Setting are: MVBR, Max 8000, Min 2250 and highest quality. I've tried 1I-14P, 1I-4P, and the standard, all with detect scene change. The results are always the same...somewhere along the line, the pixel flash shows up throughout. These flashes are not on the original (home DV captured from my camcorder).

My system is fairly fast (Athlon XP 2700+ and 1 gig ram) - I'm not experienced much with this at all, but it seems like on my older, slower, system (Athlon XP 1800 and 512 ram) I didn't have this problem.

The footage is varied - some is of a dance and very dark; other is of a t-ball game and in bright sunlight. Some is just kids standing around, then some of them running...it doesn't matter what is going on, the flashes show up.

Can anyone point me in the right directions as far as other settings to try and change? I don't really care if it takes overnight to encode - I just want to get rid of the flashes. I don't know what would be causing this so I don't know what to change...thanks[/url]
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ER Slansky
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Bivis



Joined: 10 Sep 2003
Posts: 16

PostPosted: Thu 15 Jul 2004, 7:03    Post subject: Reply with quote

Maybe "field order" is wrong? Cool Lets try "bottom" and "top", compare.
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RMN
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Joined: 04 Feb 2003
Posts: 587
Location: Lisboa, Portugal

PostPosted: Fri 16 Jul 2004, 3:02    Post subject: Reply with quote

If the settings are the same, the software will produce exactly the same result, no matter which CPU you run it on. So, probably some setting has changed.

From your description, I'm not sure I understand what the problem is. Can you capture a frame with one of these flashes and send it to me by e-mail (rmn@dvd-hq.info)?

RMN
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slanskye



Joined: 12 Jul 2004
Posts: 3
Location: San Antonio, TX

PostPosted: Tue 20 Jul 2004, 1:12    Post subject: Reply with quote

Thank you both for responding - I checked the field order and it is bottom field first - this is what DV is suppose to be, right?

And I am sending a frame with an example of the flash/glitter via email - it is too bad it is showing up because otherwise I think the results are wonderful. Thanks for any advice on what to try. What is also strange, I can encode the same DV again, using the same setting, and these flashes will show up but in different frames...I have just about everything on the PC shut down except TMPGEnc - what else could cause this type of interference??

Thanks
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RMN
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Joined: 04 Feb 2003
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Location: Lisboa, Portugal

PostPosted: Tue 20 Jul 2004, 2:59    Post subject: Reply with quote

I've seen the frame.

Those definitely do not look like encoding errors. They look like decoding or reading errors, usually caused by a damaged file (or a damaged disc, but I assume you're playing the MPEG-2 file, and not the finished disc).

Which program did you grab the frame from? Have you tried playing back the file with different players (ex., PowerDVD, WinDVD, etc.)? Are the flashes always in the same places? If you're using hardware acceleration in the player (ex., PowerDVD has this option), turn it off (it makes the image quality worse anyway, and your CPU can decode DVD MPEG-2 easily, without using the GPU).

It could be TMPGEnc that's creating a corrupted file, but I've never seen that happen, so I would suspect something else. Perhaps the file is fine but it has some detail the player doesn't like, or the file itself is damaged for some reason.

Possible reasons for file corruption are faulty hardware (CPU, RAM, motherboard chipset or the drive itself) or a hardware conflict (ex., some Sound Blaster cards caused PCI bus corruption - and consequently file corruption - when used on motherboards with the KT133A chipset).

Test your RAM with MemTest 86 just to rule that out. Also, check that your CPU and hard disk aren't overheating (rule of thumb: if you can keep your thumb on the heatsink and the disc surface, they're fine - if you can't, they're too hot), and run a full disk check (but if the drive is overheating, cool it first).

If your CPU is overclocked, set it back to stock speed. If your DVD player uses the GPU (hardware acceleration), make sure the graphics card isn't overclocked, either.

If none of this makes any difference, try turning SSE off in TMPGEnc's "environmental options" and turning off "floating-point DCT" in the "quantize matrix" tab (SSE code in some versions of TMPGEnc has a few bugs).

RMN
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slanskye



Joined: 12 Jul 2004
Posts: 3
Location: San Antonio, TX

PostPosted: Tue 20 Jul 2004, 11:05    Post subject: Reply with quote

Thank you for your suggestions - just some replies to some of your questions...when I first saw these artifacts, I checked the captured avi file first, playing back in WMP - it looks beautiful, and no artifacts.

I then checked the TMPGEnc MPEG-2 file via WMP and the artifacts are there.

I also pulled the file into both WinDVD (artifacts show up there) and then into PowerDVD to capture the frame.

I use DVD Complete to author and burn the DVD - artifacts show up on the final DVD there too.

I'm starting to think along the lines your suggesting concerning a hardware problem, mostly because I don't remember these artifacts happening when I was using my older system. Thanks for your review - I'll keep you posted on what I find.
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