class WavWriter

This class enables a client to easily create and write LPCM audio data to a

RIFF-based WAV file. After creating the WavWriter object, Initialize should

be called before invoking other methods. If nullptr or "" is passed to

Initialize (instead of a valid file name), a default file path+name of

'/tmp/wav_writer_N.wav' is used, where N is an integer corresponding to the

instance of WavWriter running in that process.

Following Initialize, the Write method is used to instruct the library to

append the specified number of bytes to the audio file that has been created.

Once the client has completely written the file, the client should call Close

to update 'length' fields in the file and close the file. If the client

wishes, it can also occasionally call UpdateHeader, to update the 'length'

fields prior to file closure. These calls help maximize the amount of audio

data retained, in case of a crash before file closure, but at the expense of

higher file I/O load.

The method Reset discards any previously-written audio data, and returns the

file to a state of readiness to be provided audio data. By contrast, the

Delete method removes the file entirely -- subsequently the object would

generally be destroyed, although it can be revived by re-calling Initialize.

Note: this library makes no effort to be thread-safe, so clients bear all

responsibilities for synchronization.