Often, user configs set options that are not suitable for encoding.
Usually, playback and encoding are pretty different things, so it makes
sense to keep them strictly separate. There are several possible
solutions. The approach taken by this commit is to basically ignore the
default config settings, and switch to an [encoding] config profile
section instead. This also makes it impossible to have --o in a config
file, because --o enables encode mode.
See github issue #727 for discussion.
This re-allows the previous behaviour of being able to reencode with
metadata removed, which is useful when encoding "inconsistently" tagged
data for a device/player that shows file names when tags are not
present.
Apparently, libav doesn't have the change for the new way to create a
libavformat context merged yet. So, we can't use that...
Rather, this commit fixes format specific avoptions another way.
On the downside, invalid format options are now detected very late, and
any attempt to set an option value to +something or -something will
append to the previously set option value (this logic can no longer be
specific to options of bitflag type, as finding out the option type is
what we simply cannot do with this interface).
This allows to define which stream is to be used as first output stream.
This is useful because dvdauthor refuses VOB files where the audio
stream is the first stream.
