This removes the onInitFile and onInitFileW callbacks from
ma_decoding_backend_vtable. This means decoding backends can no longer
implement a specialized initialization routine for loading from a file.
What this does is enforces all file IO to go through the same code path,
that being the `ma_decoder` and `ma_vfs` infrastructure. It also
simplifies the backend vtable.
The ability to initialize from memory (the onInitMemory callback) is
still available and there are not plans to remove this.
These decoders have been moved into their own subfolders under the
extras/decoders folder:
extras/decoders/libvorbis
extras/decoders/libopus
In addition to being relocated, they have also been split into separate
.c/h pairs. They now work like a more conventional library. The
implementation of these libraries have also been decoupled from the
miniaudio implementation which means they depend only on the header
section of miniaudio.h now.
With this change the custom_decoder and custom_decoder_engine examples
have been updated. To compile these you now need to link in the
miniaudio_libvorbis.c and miniaudio_libopus.c files via your build
tool. For your own code, you can still include the .c files directly
into your code if you want to compile as a single translation unit.
David Reid