Allow using video for ControlNet for target type image

[jtreminio]

Note that "Preview" might still not work here.

Hitting the button results in:

[vost#0:0/libx264 @ 0x15d05fc0] Error while opening encoder - maybe incorrect parameters such as bit_rate, rate, width or height.
[vf#0:0 @ 0x15cfa340] Error sending frames to consumers: Generic error in an external library
[vf#0:0 @ 0x15cfa340] Task finished with error code: -542398533 (Generic error in an external library)
[vf#0:0 @ 0x15cfa340] Terminating thread with return code -542398533 (Generic error in an external library)
[vost#0:0/libx264 @ 0x15d05fc0] Could not open encoder before EOF
[vost#0:0/libx264 @ 0x15d05fc0] Task finished with error code: -22 (Invalid argument)
[vost#0:0/libx264 @ 0x15d05fc0] Terminating thread with return code -22 (Invalid argument)
[out#0/mp4 @ 0x15d05640] Nothing was written into output file, because at least one of its streams received no packets.

I worked around this by following your example here.

[jtreminio]

Second commit fixes issue with "Error while opening encoder - maybe incorrect parameters such as bit_rate, rate, width or height":

CleanShot.2026-05-01.at.19.23.33.mp4

[mcmonkey4eva]

Why is this inside the ControlNetPreviewOnly area?