Compression Artifacts

[Echo147]

I brought this issue up a fair few months ago, although back then I was experiencing more freeze frames in my recompresses than distortion in the video.

I have managed to isolate a piece of video that guarantees corruption on my system at frame 659 (see attached graphic). I can reboot, and the exact same error will be created.

Note the green square, and replicated area of the chopper just to its right. The lower right becomes progressively worse in my output, until the next keyframe comes along.

I'd be really grateful if a few people could give this source video and included Virtualdub config file a go (please use it with version 1.4.13 or later, custom/old builds may not correctly load it), see if you get any artifacts at the same point.

Included in this link is source video, config file and the video I get when recompressing this source (starting from frame 659 to save filesize). www.btinternet.com/~echo147/temp/distortion.zip (3.3mb)

Hardware: Athlon Thunderbird 1.4ghz, 512mb, Geforce 3 Ti200.
Software: Win2k SP2, NVidia Detonators 30.82, Virtualdub 1.4.13.
Recompression Codec used: DivX 3.11 Alpha (low motion)
Source video format: X-Vid

Many thanks in advance to anyone sparing some bandwidth to try this out

[UncasMS]

here is what i did:

loading your SOURCE in vd_mod 1.4.13
loading the vcf

saving as avi

the result is fine!

no macroblockglitch here

[Echo147]

Hi mate,

Thanks for trying the config - out of interest do you have an Intel or AMD CPU?

I'm wondering if this is now the cause - have ordered a new XP 2100+ tonight just in case, could use a speed boost in Virtualdub whether it solves the artifacts or not

[UncasMS]

i'm running two athlon pcs

i should think your glitch could be caused by your xvid codec.

and in addition to that i'm using vd_mod not the plain vd version 1.4.13

[Echo147]

I do think that X-Vid is more sensitive to recompression, however I get these kind of distortions when recompressing even DivX 3.11 material - but it's not as frequent.

What extras are in that mod, ac3 or something? I only have an earlier 1.3 version built for VBR MP3.