Seek in video playback / transcoder?

[vbguy2011]

So, I realise that none of the avi/mkv files that I tried let me seek using jwplayer.

I note discussions on ffmpeg transcoding does not allow seeking, and other discussions where flvtool++ as step2 in transcoding would allow seeking.

However flvtool++ has been discontinued and flvtool2 doesn't seem to work that way.

Is there any method to allow users to seek during video playback?

also, shouldn't -ss %o in default ffmpeg transcode arguments allow seek? I'm just a bit confused...

cheers