ffaudio todo
------------

- Tagging: reading should probably be done through ffmpeg (unless there is a reason not to), writing through libaudtag.

Candidates with problems:

  * Apple Lossless Audio Codec (alac): typically uses same container as
    AAC (aka MP4), and hogs all files with that. This is a problem from
    probing side of things.

  * True Audio (tta): TTA files use ID3 tags, but libav* does not read
    those for TTA files. Works otherwise.

  * Shorten (shn): file durations are wrong.

  * WAVE (wav): file durations are wrong.

  * Musepack (mpc): SV7 files seem to work okay, however SV8 files
    cause severe artifacts when seeked and under some circumstances
    apparently cause the decoder to corrupt stack -> crash.

Other notes:

  * AAC: FFmpeg currently only supports AAC-LC, though there have been
    discussions on ffmpeg-devel about adding SBR (Spectral Band Replication,
    needed for HE-AAC v1) and PS (Parametric Stereo, needed for HE-AAC v2
    together with SBR).

    For now, FAAD-based decoder provides better compatibility, like
    "AAC+" which actually is HE-AAC v2.

  * Movie formats: Playing audio from AVI, MOV, etc. files is possible,
    maybe we should enable this?

  * RealAudio formats: FFmpeg supports some Real codecs, but the demuxer
    seems to get duration etc. wrong lots of the time.
