Darkening picture

[ChronoCross]

Not sure if this is an xvid issue or not but I thought it's good to start here. If I do batch encoding and do more than 3 encodes in a row. the ones after the 3rd encoder become really dark. Is this a common issue or am I the only one? Note I'm encoding anime so the opening credits are always the same. which is how I noticed it. thx

[*.mp4 guy]

Depending on the matrice you use it can sometimes brighten or darken a frame or an overall movie based on how it treats various frequencies, it sounds to me that you are encoding something then encoding the out-put over again. If this is indead what you are doing and i have not misunderstood you, then you should stop because the artifacts will get worse. Oh and by the way this isn't an xvid issue...

I beleive the effect you are experiencing comes from coefficient rounding, which when done repeatedly would become more readily visible.

[sysKin]

Originally posted by *.mp4 guy
Depending on the matrice you use it can sometimes brighten or darken a frame or an overall movie based on how it treats various frequencies, it sounds to me that you are encoding something then encoding the out-put over again. If this is indead what you are doing and i have not misunderstood you, then you should stop because the artifacts will get worse. Oh and by the way this isn't an xvid issue...

I beleive the effect you are experiencing comes from coefficient rounding, which when done repeatedly would become more readily visible. Just let me tell you that this is absolutely untrue.

[JarrettH]

He convinced me.:p

[BoNz1]

Originally posted by ChronoCross
Not sure if this is an xvid issue or not but I thought it's good to start here. If I do batch encoding and do more than 3 encodes in a row. the ones after the 3rd encoder become really dark. Is this a common issue or am I the only one? Note I'm encoding anime so the opening credits are always the same. which is how I noticed it. thx

Make sure that DivX5 isn't decoding YV12. I had noticed quite a while ago that when it decodes YV12 the image is darker than when XviD decodes YV12. This was like in DivX 5.05 days though. Maybe they have fixed it since. Other than that, that is all that I can think which would cause this. And I have no idea why it might happen in the 3rd encode other than that the 3rd was _actually_ darker originally. If you can post screenshots of the same frame from each encode (source and encoded) then you may have better luck convincing people that there is a problem.