Ohh, my bad. I opened the file from this morning again.
Seems like the only source filter which can handle the file here is DirectShowSource, seems like libav and thus ffmpegsource and livasource can't handle the file.
When using DirectShowSource I have no problem jumping inside the file.
Cu Selur
Now tested Hybrid_dev_2019.09.05-204823
Very Strange... I have a lot more wmv files that have a normal working avisynth preview, when DirectShowSource is turned off.
Normally working avisynth preview file
ID : 2
Format : VC-1
Format profile : MP@ML
Codec ID : WMV3
Codec ID/Info : Windows Media Video 9
Codec ID/Hint : WMV3
Description of the codec : Windows Media Video 9
Duration : 2 min 54 s
Bit rate mode : Variable
File, that in avisynth preview window I see only a few initial minutes of the file when I move the slider from the beginning of the end.
ID : 1
Format : VC-1
Format profile : Main
Codec ID : WMV3
Codec ID/Info : Windows Media Video 9
Codec ID/Hint : WMV3
Description of the codec : Windows Media Video 322694968 - 2-pass VBR
Duration : 29 min 0 s
Bit rate : 5 000 kb/s
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
It depends on whether libav supports that sort of wmv/asf combination, nothing I can do about it.
Cu Selur