"split interlaced fields .. and double framerate"

[cafut]

Hello,

There is a VirtualDub option which reads like the PERFECT de-interlacing 'filter' I was waiting for ages - inherently improving 'slo-mo' possibilities - but unfortunately I am too ignorant to get it working:

BEFORE selecting a DV AVI-file in the "File => Open Video File" dialog, tick the "Ask for extended options" checkbox.

The desired option is in the second section "Motion-JPEG options" (the "interlaced frame mode" Radio-Button):

"split interlaced frames into two fields (un/swapped) and double framerate"

Sadly, selecting this option seemingly has no effect at all. I would expect a 'resorted lines' result with DOUBLE the number of frames, but HALF the number of lines per frame. I guess my problem is somewhat related to the headline "MJPEG options". I know that digital video DV format in fact USES SORT OF MJPEG compression (not taking advantages out of similarities between subsequent frames).

Any ideas?

Alternatively, is someone around to know how to write a VirtualDub-filter to behave according to the above description? Is it possible at all for a filter to change such basic things like
o framerate
o number of frames
o number of lines (should be possible, see 'resize' filter)
?
The actual TASK of this filter would be very easy, as it 'only' consists of changing the LINE ORDERING within the data stream plus correcting the geometry/timing data used to interprete it.

Again, any ideas, hints?
Thank you!

Frank

[Guest]

If your input file is MJPEG encoded, it should work. If not, it won't. I remember it worked fine for my DC10+ captures.

The other alternative is to use Avisynth to split your fields.

VirtualDub filters cannot add or remove frames.

Your method is called "bobbing". It's been used for ages. Actually your method is "dumb bobbing". There are smarter ways to do it using motion estimation.

If you forget to realign the lower field up by half a line, your method will be really dumb!