Mediakit::FFmpeg::Options::OutputFileOption.new(
options: {
filter_complex: "[0:v][0:a][1:v][1:a] concat=2:v=1:a=1",
...will produce -filter_complex \\[0:v\\]\\[0:a\\]\\[1:v\\]\\[1:a\\] concat\\=2:v\\=1:a\\=1 and it does not quote nor escape space between streams and concat.
will produce
-filter_complex \\[0:v\\]\\[0:a\\]\\[1:v\\]\\[1:a\\] concat\\=2:v\\=1:a\\=1and it does not quote nor escape space between streams andconcat.