This does some refactoring to make it possible to cimpile and run FSO
without needing to link to FFmpeg. Since that eliminates support for
cutscenes or sound this is mostly useful for running a standalone server
which has no need for this anyway.
This reduces the image size of the standalone Docker image to only 20MB
and also resolves any licensing issues that might have existed.
The amount of output parameters is becoming quite large which makes it
harder to add new input parameters. For that reason I converted the
existing output parameters to a struct which cleans up the function
signature a lot.
This can be used for mark parts of the code which should be unreachable
in normal execution. In debug mode, if such a statement is reached an
Error dialog is shown which aborts the execution. In release mode the
macro is replaced with a compiler specific expression that lets the
compiler know that this part is unreachable which allows it to optimize
the code better.
This allows to use more complex file structures in the executable
without requiring that those exist as real files. The rest of the code
does not need to handle the difference between a default file and a real
file anymore which means that it's now possible to embed image files
into the executable since bmpman only needs to use the standard CFile
API.
I added two tests which check if the default file can be found and
opened and if a mod file overrides the default file which should always
be possible.
ADPCM playback was broken by #991 when an older FFmpeg version (< 3.1)
was used. The newer version has a better API for handling decoder that
return multiple frames of data per packet which I already used. However,
I didn't bother implementing that for the older API since I haven't seen
a decoder that actually returned multiple frames per packet but ADPCM is
such a decoder. This fixes that by implementing the correct behavior
with the old API.
This is the first step towards moving all audio decoding to FFmpeg which
will reduce the amount of external code we will need to include. This
only replaces the AudioStream code with an FFmpeg based solution which
should make the code easier to review.
Goober5000