add generated serial ID for exceptions
when recording is done natively, a resample process is required to
either upsample or downsample the recorded raw audio. This relatively
more time consuming task will delay the recording service in cyclic call
mode. So, the post-recording jobs are all moved to a separate thread.

append timestamp to the temporary raw PCM recordings because now
post-recording processing is multithreaded and might be overlapping in
cyclic call mode with small intervals

echo special prefix ahead of the PID of tinycapraw native process and
scan for this prefix in a while loop during the native recording