PDA

View Full Version : Recreate a wmv codec issue


zargali
17th November 2005, 12:38
I don't know if you have ever seen this, but it's a quite interresting effect produced
Open a wmv file with videolanplayer
Then go to in the middle of you video
You (well I do) will see the last picture before you go in the middle frozen, then the animations continue, until a radical change of the picture..
Ok this is not really clear
Here some chronological pictures..

The picture before I go in the middle of the video:
http://pix.nofrag.com/2d/4c/3fb0e9afcc0815b879b296e7347a.jpg

Then the effect produced by the codec issue (in the middle of the video)
http://pix.nofrag.com/2f/53/0a7bc4889e2806f410743ecfbc69.jpg

The picture that should been shown if there wasn't any codec issues..
http://pix.nofrag.com/34/01/93d72377d36c38ea493e4345bf5d.jpg

To complete my thread, here is the video showing everything
video.avi (http://www.zippyvideos.com/9375947732270116/video/)
The original video (http://media.koreus.com/banner-ads-XDEFG/200511/pub-bergenbier-menottes.wmv)

Note that the "codec effect" is stopped by a brutal change of scene (when he discover the red thing)

Ok now my question is easy, how could I create this effect with any codec (divx, wmv, xvid, whatever..)?
I don't want to use a filter with Premiere or After Effect, i just want to recreate this issue and determinate how long this effect will last...
Which setting should i use? Which codec?

Thanks you very much!!

Sharktooth
17th November 2005, 12:51
It lasts until the next keyframe and it's a bug in the encoder or in the decoder.
you can't "recreate" it with other codec if they aren't buggy in the same "way".

stephanV
17th November 2005, 13:04
VLC is just doing lazy seeking. It's not a bug in en/decoder. This used to happen for more formats (at least i saw it with MKV and OGM in VLC, but MKV is fixed now.).

Sharktooth
17th November 2005, 13:05
yes, it may be also a container/muxing tool bug.

zargali
17th November 2005, 15:17
Thanks for the replies
Well it doesn't matter if I can't do this with other codecs, I will use VLC and wmv..
If it lasts until the next keyframe, then how can I configure where the keygens are?

Sharktooth
17th November 2005, 15:23
key*frame* ... not keygen...
keyframes interval can be set in the encoder BEFORE encoding... it cant be set otherwise.

zargali
17th November 2005, 17:02
No matter.. i will encode my own video in wmv, this video was just to show you the effect...
Which program should I use to put the keyframes interval?? can't I set my own keyframes? One at this frame, another here...???

Sharktooth
17th November 2005, 18:40
the codec should support the keyframes interval... but i doubt wmv supports arbitrary keyframes displacement.
xvid does though... thru zones.