What tool to save single frames as JPGs from video playback?

[zdvd]

I need to be able to save a JPG of a frame at a specific time index from MKV files. What tool will do this? I could do a screen capture and cut out the video portion in a paint program but I need to do this for a ton of files so I'm looking for something more automated than that.

[guns1inger]

Is it the same frame (time position) in each clip ?

Most players can save a frame, as can virtualdub, however automating the capture of a particular frame would be more difficult.

[zdvd]

Different time in each clip. I want to be able to create meaningful thumbnails for icon display on a HTPC and I would have to take the captures manually at various times to achieve that... the automatically generated ones from 10s in or whatever are kind of worthless. I have avidemux for editing but I don't see a way to capture a single frame in that. I also have a couple different players and neither has any facility to capture frames built in.

Edit: Does virtualdub work with MKV? The description on here doesn't indicate that it does. It lists about everything except for MKV. Previous to this I was using some lame editing program that came with my camcorder to do this (ArcSoft Media Impressions) but it does not support MKV.

Edit 2: Also tried ImageGrab but it does not support MKV either.

[guns1inger]

You can save stills from VLC, The KM Player or Media Player Classic HC