Keyframes in saved video stream

[StellarWind]

This question is addressed mainly to VLC developers.
When the video stream is being saved into a file (either from a local file or from network), how the keyframes are treated? Will the first frame of the saved video stream be a keyframe?
The reason why I ask this question is that sometimes the frames in the beginning of the saved file are slightly distorted, and sometimes saved file does not even contain video stream. May it relate to storing keyframes?
I'm trying to save MPEG4 video stream coming from the net to an ASF file.
On the sending side I encapsulate the streams as "MPEG TS" or "MPEG PS",

Code: Select all

:sout=#duplicate{dst=std{access=http,mux=ts,url=10.0.0.9:1234}}

on the receiving side I encapsulate received streams as "ASF".

Code: Select all

:sout=#duplicate{dst=std{access=file,mux=asf,url="1.asf"}}

I'm using VLC 0.8.4 under WinXP.