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Old 21st May 2004, 12:58   #3  |  Link
JJ
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Join Date: Aug 2003
Location: Cracow
Posts: 13
Quote:
Originally posted by unmei
[B]first off, it works. =)
Thanks for testing it
Quote:
Now, the problems i found: the direct show decompressor seems to have quite some startup problems in itself. When i play the file in MPC there is first a lag - the video starts black for ca 10 frames, but the direct show decoder shows black for about 2.5 seconds (60 or so frames) and then the direct show decoder outputs wrong colors (like some colors replaced by others) for about 10 sec, then after a scenechange (about the 9th keyframe) all direct show decoder related problems are gone.
Yes, I can see it too with the file you provided. I'll have to investigate it once I get home.
Quote:
[edit]i found these effects seem related to startup of the codec or player. When i replay the file w/o closing the player they do not appear. I think it's also possible you won't see them on a faster computer because, even if the CPU here is not at 100% on startup, it seems the duration of the distortion is somehow related to how much CPU (or RAM) it has at hand.[/edit]

When i talked about direct show decoder problems i meant, they don't show up when i browse the file with VirtualDubMod.
Maybe that's because there's no directshow decoder, just the VfW wrapper
Quote:
The test file i made, i used the default max quality but unchecked the smooth checkbox. Actually i expected a huge but quite lossfree encode, what i got is not that huge but it shows many artifacts. I wonder if you could not set the max higher - i mean these artifacts don't look like errors, but like the "sacrifice" of a lossy encoder. I'm going for a encode with the slider somewhere in the middle next so i can see how small it will get.
It's because I started with a quantization matrix with high coefficients. Unfortunately the code for the entropy coding won't work with another matrix ATM - I'm currently working on improving the Huffman compression, the highest quality setting should look much better in the next release (it will probably take more space though).
Quote:
Now all this might sound very discouraging, but i think it is not! This codec works - it doesn't crash and the output looks like the input, just the speed and quality are to be improved.
As I said, this is just a starting point. I'm trying to make it better .

Thanks,
JJ
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