instead of only AV-specific options. The previous code assumed that any
option not defining the codec in an `ffpreset` file is an AVOption. This
for example prevented the use of options defined in `OptionDef[]`, like
`-pix_fmt`, as part of preset files, requiring users to type these out
every time.
Closes: #1530
Signed-off-by: Andreas Hartmann <hartan@7x.de>
11a89bfe7b