Xvid Playback Issue

[charlieb]

I'm having a problem playing an Xvid that I (ahem) aquired. It was part of a bunch of (ahem) episodes. Some of them play just fine (great in fact) bit some of them are really mangled. The nature of the mangling is that the sound plays on but I get random frames maybe 1 frame every 5 seconds and sometimes the frame is a mixture of two unrelated frames where one is transparently overlayed on top of the other, and sometimes a little burst of correct video, very strange.
Normally I would say f it and put it down to file corruption but they all play on my linux box with mplayer just fine, no issues what so ever. I looked more closely at the mplayer output and it seems that the good ones are divx and the bad ones are xvid. There also seem to be some other differences. First I will post just the differences so as not to clog the tubes:

Works:
VIDEO: [DIVX] 480x360 24bpp 25.000 fps 576.5 kbps (70.4 kbyte/s)
...
Starting playback...
[mpeg4 @ 0xb6c81ba8]looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag
VDec: vo config request - 480 x 360 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is undefined - no prescaling applied.
----------------
Doesn't work:
VIDEO: [XVID] 480x360 24bpp 25.000 fps 793.2 kbps (96.8 kbyte/s)
...
Starting playback...
VDec: vo config request - 480 x 360 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.33:1 - prescaling to correct movie aspect.
VO: [xv] 480x360 => 480x360 Planar YV12
[mpeg4 @ 0xb6d4dba8]frame skip 8 0
[mpeg4 @ 0xb6d4dba8]frame skip 8 0
----------------

What could be causing this wierdness? I am on fw 2.0.0 in case that makes a difference. I will upgrade this evening when I can get to my mains adaptor. Also I am playing with "full" speed playback.

Cheers,
Charlie.

 

[charlieb]

After much searching and hair pulling I found that the following re-encoding works quite nicely

mencoder bad.avi -ovc xvid -oac mp3lame -xvidencopts bitrate=300 -vf scale=320:-3 -lameopts abr:br=98 -o good.avi

I'd still appreciate any input anyone else could give.

Cheers
Charlie

 

[sam fisher]

After much searching and hair pulling I found that the following re-encoding works quite nicely

mencoder bad.avi -ovc xvid -oac mp3lame -xvidencopts bitrate=300 -vf scale=320:-3 -lameopts abr:br=98 -o good.avi

I'd still appreciate any input anyone else could give.

Cheers
Charlie

I'd switch to 512 KBPS bitrate.

 

[nubie]

The nature of the mangling is that the sound plays on but I get random frames maybe 1 frame every 5 seconds and sometimes the frame is a mixture of two unrelated frames where one is transparently overlayed on top of the other, and sometimes a little burst of correct video, very strange.

It sounds like B-frames to me, a keyframe that it should wipe the output and start fresh decoding from the frame. But it doesn't recognize that it should and garbage fills the screen.

If you found a workaround then thumbs up . I will check up on that if I ever run into this problem.