Really pixelated every 30 frames or so at DVinfo.net

Matthew Craggs · August 28th, 2008, 08:48 AM

Hey all,

I have a bit of a problem and was wondering if anyone could suggest could throw in their 2 cents.

I am cutting a wedding and there is a span of about a minute where the video "pulses" (best word I can think of to describe it). Every thirty frames or so, the frame is extremely pixelated. It's like someone took a picture with their cell phone and made a 16x20 print of it. Really blocky. If you blink every 30 frames you'd miss it and it would look fine.

It doesn't show up in Final Cut, but when you export a MPEG to DVD Studio Pro, you can see it in DVD Studio Pro. I export the MPEG using the Compressor High Quality DVD 90 minutes preset.

It was shot by someone else so I'm not sure what camera/shutter speed/etc was used, but I can say that it's 60i SD widescreen footage.

I'm at a loss of how to debug this situation. I was thinking it was an interlacing problem (fields getting reversed) but it's only for a minute or two in the footage.

Does anyone have any suggestions about how I debug?

Has anyone had the same problem?

Thanks in advance.

Aric Mannion · August 28th, 2008, 01:31 PM

The only time I've seen this is exporting an MP4, it had to do with the keyframes which must have been set to 30. So every second the image would fall apart to blocks. It looked much better w/ the keyframes set to auto. I don't know in your case but that might be a place to start looking.

August 28th, 2008, 08:48 AM	#1
Matthew Craggs Major Player Join Date: Nov 2006 Location: Welland, Ontario Posts: 311	Really pixelated every 30 frames or so Hey all, I have a bit of a problem and was wondering if anyone could suggest could throw in their 2 cents. I am cutting a wedding and there is a span of about a minute where the video "pulses" (best word I can think of to describe it). Every thirty frames or so, the frame is extremely pixelated. It's like someone took a picture with their cell phone and made a 16x20 print of it. Really blocky. If you blink every 30 frames you'd miss it and it would look fine. It doesn't show up in Final Cut, but when you export a MPEG to DVD Studio Pro, you can see it in DVD Studio Pro. I export the MPEG using the Compressor High Quality DVD 90 minutes preset. It was shot by someone else so I'm not sure what camera/shutter speed/etc was used, but I can say that it's 60i SD widescreen footage. I'm at a loss of how to debug this situation. I was thinking it was an interlacing problem (fields getting reversed) but it's only for a minute or two in the footage. Does anyone have any suggestions about how I debug? Has anyone had the same problem? Thanks in advance.

August 28th, 2008, 01:31 PM	#2
Aric Mannion Major Player Join Date: Apr 2006 Location: Boston, Massachusetts Posts: 616	The only time I've seen this is exporting an MP4, it had to do with the keyframes which must have been set to 30. So every second the image would fall apart to blocks. It looked much better w/ the keyframes set to auto. I don't know in your case but that might be a place to start looking.