* change the way the mixer is instantiated by the backend. In particular, it would be nice if the sample rate could be passed in via the constructor
* the "isReady" code is irritating. Most engines ignore it anyway. It's primary purpose is to allow ScummVM to run even if not digitial audio out is available. A better solution would likely be to implement a fake mixer class, which simply discards audio data which is passed to it immediately. This means that the normal mixer will always consider itself to be "ready", and that it will be up to the backend to use the "fake mixer" if it can't provide audio out for some reason.
==== Audio streams ====
* Add a "SeekableAudioStream" class, which would allow seeking in an audiostream: Forward / backward; offset is specified in milliseconds. Then, convert at least the MP3/FLAC/Vorbis audiostream classes to subclass that, and also adapt the corresponding factory functions. Converting more would obviously be nice, too.
==== CD ====