-rdenotes the frame rate you want the video to be, here it's being defined as 60 frames per second.
-fdefines the pipeline, in this case it is called
image2and is image to video.
-sdefines the resolution, make sure it matches your quilt dimensions!
image$04d.pngrefers to the file name and amount of numbers following the filename. Typically image sequenes are saved out sequentially like this: filename0001.png, filename0002.png..... the
%04drefers to the four digits at the end of the name. If your file has a different number of digits please adjust the command to the appropriate number.
-vcodecrefers to the encoding library, in this example we're using libx265 which is a CPU encoder for the h265 codec.
-crfis the quality of the video. 0 is the highest quality but will also result in the largest file and be very difficult to playback. 25 is a good number.
-pix_fmtis the format for the actual picture format, this must be yuv420p.