I am not able to figure out how to get ffmpeg to make a video that combines (muxes) half-height-cropped from two video sources. The latest generation of ffmpeg (3.x) has a "vstack" filter.
My screen resolution is set to 1280 by 720 pixels.
I have a webcam that is set to provide video at that same resolution.
I want the top half of the webcam's input/feed/stream to be layered on top of the bottom half of the screen-capture-recorder (recording my desktop).
Both source video streams, plus the end output result will have a width of 1280 pixels. The combination of the half-height 2 video stream inputs will end up filling up 720 lines of vertical resolution.
This should be simple.
I'll paste a few of the commands that I've tried and that have failed to work.
ffmpeg.exe -f dshow -i video="screen-capture-recorder" -f dshow -i video="Microsoft LifeCam HD-6000" -vf "crop=1280:360:1280:360" -filter_complex vstack -vcodec libx264 -pix_fmt yuv420p -preset ultrafast 6000screen_take1.mkv
I even tried adding : "[0:v][1:v]vstack[v]" -map "[v]" to that , above (previous) command.
See my Google Doc for complete output (what was in my cmd.exe window) :