FFmpeg 3.1.11
Since* 2.8
#

Stack input videos vertically.

All streams must be of same pixel format and of same width.

Note that this filter is faster than using overlay and pad filter to create same output.

The filter accept the following option:

inputs

Set number of input streams. Default is 2.

shortest

If set to 1, force the output to terminate when the shortest input terminates. Default value is 0.