Sorry but this answer does not say anything useful... or the program can not do this what I expect.
I load two videos: left and right, but seems there is no way to combine them.
Seems that NCH expects just mixed frames... So, what is intended this functionality for?
When I say: take this video as stereo (left/right), the only thing what the program does is stretching the frame!!!
Was trying to export stereo, but the result was that both streams (left and right) were identical.
...what I expect that the program should do, is:
1) give the possibility to synchronize/trim two video streams (This enables perfectly),
2) shuffle streams, taking as the first frame, the first one of the declared right/ left stream (dependently on the desired output configuration);
3) "Glue" pairs of frames (dependently on the desired output configuration);
4) Export the video in the desired format.