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| maupet |
| Posted: Oct 20 2002, 06:37 AM |
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Unregistered
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Hi,
I use div 5.02 for video compressing my mpeg files with VirtualDub. However, I notice that after compressing the file, there are flashing right blocks on the right edge of the screen. The flashing doesn't happen constantly; it happens every couple minutes or so. Does anyone have the same problem, or know what is causing this? It only happens on the right edge of the screen. The original mpeg file doesn't have the flashing blocks. All my mpeg files are captured at standard VCD quality. I use the default settings by divx to compress (1-pass, bitrate 780 kbps...)
Thanks,
maupet |
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| Neo Neko |
| Posted: Oct 20 2002, 06:48 AM |
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VirtualdubMod Alpha tester
Group: Vdubmod Alpha Testing Team
Posts: 474
Member No.: 24
Joined: 11-July 02
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I honestly can not claim to know the answer to this. My best guess is that VCD being already low quality video then recompressed to an even more frugal MPEG4 video, is causing the encoder problems encoding the MPEG1 Macroblocks. The better the source the better your results. VCD is the low end of my quality scale.  Further compress an overcompressed video etc and weird things happen. |
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| phaeron |
| Posted: Oct 20 2002, 08:52 PM |
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Virtualdub Developer
Group: Administrator
Posts: 7773
Member No.: 61
Joined: 30-July 02
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VirtualDub's MPEG decoder doesn't perform full clipping on source files due to the annoyance of partial chroma pixels on the right and bottom borders. The border pixels normally show up green. However, this only occurs if the width and height aren't multiples of 16, and I don't think this is the case for any VideoCD resolutions.
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| maupet |
| Posted: Oct 21 2002, 04:55 PM |
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Unregistered
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thanks for your replys. I capture the mpeg 1 files at a resolution of 352 x 240 VCD quality. Aren't both of these at multiples of 16? I notice there is also a depth restriction when I choose Div 5.02 for video compression. It says that the only valid depths are 24 32. Ive always ignored this - is this something I need to worry about?
Thanks,
maupet |
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| Kippesoep |
| Posted: Oct 21 2002, 10:47 PM |
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Moderator of the Virtualdub support forum
Group: Moderators
Posts: 447
Member No.: 441
Joined: 6-October 02
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VD won't allow you to compress using a codec if that codec won't accept your file as input. When using "Full processing mode", the video is converted to 32bit anyway, so that can't be the problem. DivX also supports many YUV input formats as well, BTW.
There seem to be some very odd compression problems with DivX 5.0.2. They usually turn up as purple splotches in dark areas, though. It seems to vary depending on the source material and the format (bit depth, resolution) as well as the version of DivX. |
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