Unify online and single mode?

[superbock]

#185 introduces a new online mode for programs which can be used to process live input signals. If an input file is given, this is used instead. However, this behaviour greatly overlaps with the existing single mode.

Therefore I propose to unify these two modes (i.e. use only the single mode) and use it for processing of either a single input file or live audio input.

This would further clarify the meaning of the online parameter, which is used to change the behaviour of certain processors (e.g. uni- or bi-directional RNNs, Viterbi or forward decoding). These processors can then be then called with both online and offline settings either on a frame-by-frame basis (saves memory) or processed at once (saves time).

Any comments?

[superbock]

I think it is better to keep both modes, to make the calling interface clearer and less error prone.

While unifying the two modes would have required to pass extra options to the single mode, it is much clearer calling ProgramXY online instead of ProgramXY single --online. Still, the latter is supported with input files.

With the latest attempt to fix this issue the single mode has the following use cases:

• process online processors without the overhead of calling it frame-by-frame
• process offline processors with multiple cores
• process online processors with blocks of given size (TBD)