MKV issues > help

[Jan Gruuthuse]

You did not read what I wrote: http://avidemux.org/smif/index.php/topic,11624.msg72763.html#msg72763
Is not freely accessible: It requires me to install iLivid Add-on to view or download! I'm not interested doing so!

[AQUAR]

I DL'd the sample MKV and had a quick look.

The sample seems to be a progressive recode of some interlaced material, but without the application of any form of deinterlacing.
Avidemux does not see any index frames in this sample MKV, hence the inability to seek with the "arrows".

Purely a guess -  its an unusual recode of the original interlaced material - maybe Fields with I and P properties were combined into a P frame.
The frame rate of the sample is also little strange at  24.958 Fps.   

Bit outside my expertise so hopefully someone else can be more precise.

My suggestion, use TsMuxer and remux the video and audio streams into a transport stream (more robust container) and avidemux should be able to index that and be able to seek with the arrow keys.