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Blue lines in MPEG-2 Compression

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Ryan aqu
Blue lines in MPEG-2 Compression
on Mar 28, 2011 at 3:17:01 pm

The source is from a ProRes mov file, the length is about an hour. But this ONE SECTION of less than 1 minute is producing some flashing blue lines on the top of the screen.

It is NOT present on the source timeline nor the source quicktime export.

I've tried EVERY setting of upper first/lower first. But the only way the blue lines go away is if I compress as PROGRESSIVE. (in Apple Compressor)

But I can't compress it as progressive, because it looks stroby and looks bad on a TV. (Looks fine on a computer)

(I've also tried compressing in Adobe Media Encoder, and Cleaner XL) (same results)

What can I do to fix this?!?! Help!!

Here is a link to a screenshot.

http://i28.photobucket.com/albums/c212/starterkit/blue.jpg


The final output for this file is DVD Studio Pro.


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Ryan aqu
Re: Blue lines in MPEG-2 Compression
on Mar 28, 2011 at 4:12:36 pm

Other info.

Computer - Mac
Operating system: 10.6.6
Software used including version number: DVD Studio Pro 4.2.1, Compressor 3.0.5
Source codec (file you put in): ProRes422
Destination codec (file you want out): MPEG-2
Type of destination use: DVD


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Craig Seeman
Re: Blue lines in MPEG-2 Compression
on Mar 29, 2011 at 2:05:40 pm

It sounds as if something is going on in the vertical interval of a specific shot or series although the symptoms don't ring a bell as to what it might be. What was the original source of that shot or series of shots?



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Ryan aqu
Re: Blue lines in MPEG-2 Compression
on Mar 29, 2011 at 3:01:15 pm

I think I got it figured out. The client went back to their original timeline, and it they cropped out a little more of the background at the top.

upon re-compress, the blue line was gone!

Although it is still strange that the blue lines did not show up in the exported quicktime.


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Craig Seeman
Re: Blue lines in MPEG-2 Compression
on Mar 29, 2011 at 3:43:15 pm

[Ryan aqu] "Although it is still strange that the blue lines did not show up in the exported quicktime."

That can happen if it's on the edge of the blanking interval. It might not be displayed. A lot of compressionists crop in a pixel or few on the edges because "edge schmutz" happens often enough. You can see things on the edges if the source came from analog tape at some point for example. It can range from the odd bit of VITC or Closed Captioning or equivalent to head switching or skewing from the tape deck.



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