This provides a new method for enabling spdif passthrough. The old
method via --ad (--ad=spdif:ac3 etc.) is deprecated. The deprecated
method will probably stop working at some point.
This also supports PCM fallback. One caveat is that it will lose at
least 1 audio packet in doing so. (I don't care enough to prevent this.)
(This is named after the old S/PDIF connector, because it uses the same
underlying technology as far as the higher level protoco is concerned.
Also, the user should be renamed that passthrough is backwards.)
bstr.c doesn't really deserve its own directory, and compat had just
a few files, most of which may as well be in osdep. There isn't really
any justification for these extra directories, so get rid of them.
The compat/libav.h was empty - just delete it. We changed our approach
to API compatibility, and will likely not need it anymore.
The mp_select_decoders() function doesn't have a log context (and I
don't want to give it one), so get rid of the mp_msg error message by
enhancing the semantics such that the syntax error is replaced by a new
feature. Now doing "--ad=something" will enable all decoders in the
"something" module, same as "--ad=something:*". Pretty useless, but gets
rid of the annoyance.