Chris Tipton-King
Level 1 (25 points)

Q: Motion estimation artifacts in MPEG-2 DVD files

I'm noticing some rather pronounced motion estimation artifacts in my MPEG-2 for DVD files, seemingly no matter what settings I use. They appear as parts of the frame that move in the wrong direction or appear to warp, like footage that's been slowed down too far using the Optical Flow slow-mo option in FCP.

 

The master is a 1080p24 ProRes HQ file. This happens no matter which preset I use, single or multiple-pass encoding, different bitrates etc…

 

Anyone know what's going on?

Posted on Sep 12, 2015 1:38 PM

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Chris Tipton-King

Q: Motion estimation artifacts in MPEG-2 DVD files

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  • by BenB,

    BenB BenB Sep 12, 2015 2:06 PM in response to Chris Tipton-King
    Level 6 (10,036 points)
    Audio
    Sep 12, 2015 2:06 PM in response to Chris Tipton-King

    What versions of FCP, Compressor, OS X are you using?

    What is the duration of your project in FCP?

    What hardware are you running?

     

    You can set Compression Markers in Compressor just before those areas, and it should help.  My guess is these are areas of intense motion in the image.

    http://help.apple.com/compressor/mac/4.1/#cpsr0ca43996

  • by Chris Tipton-King,

    Chris Tipton-King Chris Tipton-King Sep 14, 2015 12:27 AM in response to BenB
    Level 1 (25 points)
    Sep 14, 2015 12:27 AM in response to BenB

    FCP 10.2.1

    OS X 10.10.5

    Macbook Pro 15 Retina Mid 2012

     

    It's a 90-minute comedy feature, nothing unusual. It's not just in a few places with motion, it's everywhere, even relatively static shots distort. Also, I'm noticing a ton of banding and blocking, it looks like I encoded at a very very low bitrate, when in fact I did not. I tried 8 Mbps CBR single-pass and got the same results. The resulting file size is 5.5 GB, so it's not that it's ignoring my bitrate settings.

  • by Russ H,

    Russ H Russ H Sep 14, 2015 4:50 AM in response to Chris Tipton-King
    Level 7 (21,905 points)
    Quicktime
    Sep 14, 2015 4:50 AM in response to Chris Tipton-King

    Sometimes, downscaling HD to SD introduces artifacts – particularly with MPEG2 compression. Try setting the Resize filter to Best to see if that helps.

     

    It would be helpful if you could upload a short, representative section of your clip to a file sharing web site so we can see what you're talking about.

     

    Russ