MeGUI x264 encode for BluRay: CUE problem?

[gatewaymastering]

Newbie here.

I am encoding material for Blu-Ray. I am using the MeGUI x264preset "Standalone-Blu-ray" at 25 Mbps. The clarity to the original is amazing but I am getting lines in the encoded AVC file. It almost looks like an interlacing problem.

The source is:
Matrox 8bit Uncompressed AVI file (4:2:2) RGB
1920x1080i 29.97 from Adobe Premiere (Matrox AXIO LE System)

I change the file to YV12 before encoding. I have tried "encode as interlaced" feature in MeGUI but still has the lines and is a little soft compared to not using it. I tired de-interlacing the material first but still get similar results as using the "encode as interlaced"

The one warning I get is:
Your AviSynth clip has the following problem:
AviSynth clip doesn't have mod16 dimensions:
Width: 1920
Height:1080
This could cause problems with some encoders,
and will also result in a loss of compressibility.
I suggest you resize to a mod16 resolution.
Continue anyway?

I have attached a couple of before and after frames. Any ideas to try would

be great.

Thanks,
Brian

[Guest]

Looks like Chroma Upsampling Error (CUE) due to wrong YV12 sampling.

[gatewaymastering]

Right below the timecode. This is only one part of the image. I can post other sections of the image.

It's not blocking. In other sections it looks like the image does not line up.

I'll post another section.

Thanks

[gatewaymastering]

Another section of video.

If it is Chroma Upsampling Error, is there a filter I can use to fix it? I am using the ConvertToYV12() in avisynth.

[gatewaymastering]

Sorry previous message Original2 and Encoded2 are reversed.:stupid:

[Guest]

If it is Chroma Upsampling Error, is there a filter I can use to fix it? Post an unprocessed source sample and your exact script.

[gatewaymastering]

How big of a sample do you need? This is a menu for a blu-ray disc. It's 1920x1080 uncompressed 1 minute in length and about 7 gig in size.

Thanks for your help.

[Guest]

Big enough to include a few frames with the bad one. Don't forget to give your script too.

Here's something to try:

In your script try both these conversions:

ConvertToYV12(interlaced=true)

and

ConvertToYV12(interlaced=false)

Do they both fail as you describe?

[gatewaymastering]

I tried ConvertToYV12(interlaced=false) and ConvertToYV12(interlaced=true). Both exhibit the same problem but the interlaced = false is less pronounced.

You can download the file from our website http://www.gatewaymastering.com/videotestfile.html

It's a 1 second piece. Matrox Uncompressed AVI (8 bit 4:2:2 1080i RGB) file. The script just has two lines:

AviSource("G:\TestEncodes\TestMenu.avi")
ConvertToYV12()


Thanks again!

[Guest]

I serve the script into VirtualDub and don't see any CUE. I don't see how x264 could introduce it. So, how are you viewing the AVC and making the screen grabs that you showed? Can you post a small sample of the encoded AVC file?

[gatewaymastering]

I loaded the files into After Effects CS3. Rendered out still frames. Is there another viewer out there where I can compare the original and the rawavc file?

If you go to the same link as before, I put a new link at the bottom of the encoded video file.

You Rock!

[Guest]

There are no CUE artifacts in the encoded video, as viewed with DGAVCIndexNV or Media Player Classic+CoreAVC.

So apparently AE upsamples the chroma for rendering out the still image, and when he upsamples he uses interlaced upsampling instead of the required progressive. This is the classic cause of CUE. For example, early DVD players always upsampled as interlaced because they ignored the progressive_frame flag. You can read all about it here:

http://www.hometheaterhifi.com/volume_8_2/dvd-benchmark-special-report-chroma-bug-4-2001.html

Your encode is fine, don't worry.

Your ConvertToYV12() should either pass no parameter so as to default to progressive, or it should pass interlaced=false.

Maybe AE has some option to control upsampling.

[gatewaymastering]

Thanks so much for your time!

The encoder is amazing.:thanks: