Support AAC format

[duysqubix]

Any plans to introduce an AAC Decoder?

Original issue: faiface/beep#55

[MarkKremer]

"There are no plans, just pull requests :)" - faiface

[johnrijoy]

Not sure if this can be helpful. Found this go library on decoding AAC to PCM samples go-fdkaac.

[MarkKremer]

Thank you for your reply. I'm not too familiar with cgo but I feel like it would diminish the ability to cross compile or use Beep cross platform.

[dusk125]

So oto uses purego which allows dynamic linking with c libraries without the need for cgo. In general I would warn against cgo unless the package does a good job compiling and distributing the c-stuff... from the looks of fdkaac, if a beep user wanted to use it, they would need to do additional steps before go compilation.

edit: removed incorrect information about purego