audio support

[lxkain]

use QTs cross-platform audio support for recording and playing waveforms.

[lxkain]

we do like the simpleaudio package, but on Windows a compiler is needed when installing via pip. Another option is to create our own conda package.

Using QT would also enable recording, also real-time recording, i.e. see the waveform / spectrogram as it is being recorded.

[lxkain]

Another related issue: playing back or recording whole files could easily be added, but a common-use case is to select regions of interest for playback. This means that the notion of region-selection needs to be addressed first. Interacting with this is also the useful feature of playing back one region of a partition.

See also #18 and #19.

[rcgale]

+1 on this issue

For my use case, which mostly involves analyzing ASR-generated labels, simply being able to hear the audio and view a synchronized cursor in the view would greatly enhance the utility of the product. Regional playback would also be nice, but is certainly secondary for me.

[lxkain]

OK, perhaps we can do a simple audio playback of the whole file first, without region selection. I am not sure if we can support a synchronized cursor at this time, due to a lack of that concept for now (#19)