This makes the code simpler and avoids mixing designated and
non-designated initializers in a potentially unsafe way in avconv.

It splits the commandline into a more convenient internal representation
for further parsing.

This will allow e.g.
- processing global options first independently of their location on the
  commandline, eliminating ugly hacks for processing e.g. cpuflags
  first
- better options validation and error reporting. It is now possible for
  the parser to know that it's applying an input option to an output
  file or vice versa and act accordingly.

Anonymous structs cannot be forward declared and have no benefit.

func2_arg is the same as func_arg, except it has one additional
parameter. Change all func_arg callbacks to take that parameter (and
ignore it).

Currently it takes a mask and value, such that options for which
(flags & mask) == value.

Change it to take required flags and forbidden flags instead. This is
shorter and simpler to understand.

This option does not do anything.

Also remove OPT_GRAB, since -isync is the last option using it.

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.

Also use it in the declaration of the various exit_program
implementations in avtools.

inspired by a clang-scan report.

This allows passing the right options to encoders when there's more
than one encoder for a certain codec id.

Signed-off-by: Martin Storsjö <martin@martin.st>

It will be used by avplay.

Also add the public interface libavfilter/buffersink.h.

Based on a commit by Stefano Sabatini.

This way we don't require a clearly defined corresponding input stream.

The result for the xwd test changes because rgb24 is now chosen instead
of bgra.

The preset files have been renamed some time ago.

CC: libav-stable@libav.org

Useful for testing.

This symbol name clashes with a symbol in gnutls, if linking
statically to that library.

Signed-off-by: Martin Storsjö <martin@martin.st>

This way it can be applied to cmdutils too -- e.g. showing the banner
and printing startup messages.

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

This allows options like -target, which are just shortcuts for other
options, to work without dummy function for all options they invoke.

This is the first step to removing the globals plague from avtools.

This will be useful in the following commit.