The reason for moving the implementation out from CSoundGenerator into
its own class is, because CSoundGenerator was a very complex and
obscure class. It mixed many tasks in one place. CSelcalPlayer
is designed to play SELCALs only.
The following design changes have been made, compared to CSoundGenerator:
* Use pull mode instead of push mode. QBuffer is used as the QIODevice and
is a wrapper around QByteArray. Therefore it is not necessary to
implement our own QIODevice.
* Internally it uses a CThreadedSelcalPlayer to relieve the load of the
main thread. CThreadedSelcalPlayer inherits CContinuousWorker, no
low level QThread implementation was necessary.
* Push mode was not implemented.
* It is important that the QAudioOutput is allocated in the worker thread.
QAudioOutput allocates internal objects, which cannot be moved to
the worker thread.
* Data caching. The generated seclal audio data is cached.
refs #736
