show_foo() functions are declared as void show_foo(void), but called as
int show_foo(const char*, const char*).

Make it print a list of AVCodecDescriptors.

Add new -decoders and -encoders options that print lists of decoders and
encoders respectively.

This saves a bit of typing.

Signed-off-by: Mans Rullgard <mans@mansr.com>

Also document it and replace undocumented and inconsistent
'-sample_fmt list' syntax with -sample_fmts.

Make ff* tools only accept opt_* functions taking two arguments.

The distinction between functions with one and two arguments is quite
pointless. Simplify parse_options() code.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

formats.

Originally committed as revision 20909 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 20906 to svn://svn.ffmpeg.org/ffmpeg/trunk

filters.
Currently filters are not registered, so the option will show none.

Originally committed as revision 20807 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 20664 to svn://svn.ffmpeg.org/ffmpeg/trunk