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  1. Member
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    I'm wondering if any of you have come across and hopefully fixed a problem I am having.

    I am trying to convert some anime files from XVid to MPEG-2 for DVD authoring. The problem is that I am getting very ugly big square blocks in the encoded file in frame sequences where there are sudden changes in brightness/contrast. See below for a couple of example "frame shots":

    Source avi:


    Encoded avi:


    I encoded the file using TMPGEnc Plus v2.5 with the following settings:
    Stream type: MPEG-2
    Size: 720x480
    Aspect ratio: 16:9
    Frame rate: 23.976
    Rate control mode 2-Pass VBR (average bit rate 5000)
    Encode mode non-interlace (the source is not interlaced)
    Motion search precision: Highest quality

    The source avi file is encoded with the XVID codec, resolution = 640x368

    If you want to look at samples of the source and encoded videos:
    Source: http://www3.telus.net/public/a5a47927/clip.avi
    Encoded output: http://www3.telus.net/public/a5a47927/clip.m2v

    Thanks in advance for any help you can offer![/url]
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  2. I'm a MEGA Super Moderator Baldrick's Avatar
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    Have you tried any other encoder to see if you get similiar problems? Like HCEnc.
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    I suppose "Rate control mode 2-Pass VBR (average bit rate 5000)"
    is the source of your current problem. Try "Constant Quality" @70% and
    max bitrate=6400kbps. Besides, "Motion search precision: Highest quality"
    is a waste of time --- just "high quality" is more-than-sufficient.
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  4. Member vhelp's Avatar
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    hewsongs,

    Your problem with "blocky" artifacts is the result of how XviD's is decoding the video during
    the editor or mpeg encoding tools call-back to the decoder. I've had this problems in some
    of my dealings with XviD. Heck, I even use it now-a-days where I am exploring the posibility
    of an alternative for capturing analog cabletv with this codec because it captures more "time"
    in less space than my prev preference, Lagarith codec. Both codecs finalize in the YUV color
    space -- YV12.4:2:0 -- but depending on how it is being used to decode the xvid video, it
    can cause these artifacts. But so far, I have not seen them in my analog captures to date.

    TIP: save out to a *new* avi video of another codec, and see how it goes.

    The above tip should work!

    -vhelp 4605
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  5. HCEnc (free) like Baldrick suggested works great

    Here is an encoded clip using your settings
    http://www.megaupload.com/?d=5KSO7LUR
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  6. Member vhelp's Avatar
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    Ok. I just ran your xvid through my version of TMPGenc and made two encode tests, one for
    CQ and the other, for 2-pass. And after examining both test clips, they played without any
    artifacts. So my theory was prob correct, that it depends on how the xvid is being called for
    the decoding part. On the other hand, it could have been your verison of TMPGenc.
    I don't know. But I'm using v2.50, if that makes any difference.

    -vhelp 4606
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    vhelp seems to be right, I thought that only crappy formats
    and containers "such as" FLV would produce "artifacted outputs"
    depending on the chosen decoder
    (cf.: https://forum.videohelp.com/topic348207.html#1828502 )
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  8. Member
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    vhelp:

    Thanks for taking the time to look at this. I am also with TMPGEnc v2.5. I tried installing the software on a different computer. This time it encoded without the ugly artifacts! So my solution is to work on that computer.

    The computer I was using originally has a pile of different video processing stuff on it, so I'm guessing there may have been some conflicts - I noticed there were specific codecs for DivX and XVid, but I also had ffdshow which could process them too (I think). Have any of you heard of codecs conflicting with each other like that?

    Looks like that computer is ready for a rebuild...

    Thanks again for your help!
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