Also move them to multimedia filters section.

Use verbal form to describe "outputs" options, and mention it in the
manual.

Signed-off-by: Paul B Mahol <onemda@gmail.com>

It was removed in 32a7b858.

The next commit will introduce a proper decimation filter to be used
along with the field matching filter. To avoid confusion with this
filter which has currently a very limited usage (and will not work
properly with the fieldmatching filter), the new decimation filter will
take the decimate name, and this filter is renamed to mpdecimate.

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Fix evaluation of expressions containing the t variable.

This is inconsistent with the rest of the docs.

Move validation from init to query_formats().
Accept the formats lists as binary options.
Signed-off-by: Nicolas George <nicolas.george@normalesup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Add av_int_list_length() to compute a list length.
Add av_opt_set_int_list() to set a binary option.
Signed-off-by: Nicolas George <nicolas.george@normalesup.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

This filter is not required anymore with aformat. Drop it at next bump.

This is heavily based on 2831b307 by Anton Khirnov <anton@khirnov.net>

This also drops support for "flat syntax" and "reinit" command.

"reinit" command is not very robust and complicates the logic more than
necessary, since requires to reset all the options in the command.

*This is a syntax break*.

Signed-off-by: Anton Khirnov <anton@khirnov.net>