First version of ReNumber.
Click and drag folder containing frames recorded by ViewR onto Renumber to generate input file for ffmpeg.
Then run this command in the folder to convert contents of folder into a video.
ffmpeg -f concat -i input.txt -vf "transpose=2" -vcodec libx264 -crf 15 -pix_fmt yuv420p capture.mp4
ffmpeg must be part of your computer's environment variables.
The script above converts your folder of frames into a video that's rotated 90 degrees counter clockwise as an mp4 with h.264 encoding.