The tool record_time_signal is designed to measure the performance of
QAudioInput. The intended use is to record a short period of live
audio from an on-air time signal of known good quaility, the basic
required parameters are an audio input device, an output file name
(.WAV), a start second in a minute, and a duration in seconds. So for
example to record the time signal ticks and fast data at the top of
the minute:
$ record_time_signal -o wwv.wav -s 55 -d 15
will record 15s of audio at 48000Hz sample rate, stereo, from the
default audio input device, starting at second 55. This will use a
separate timer to stop the recording which is likely to leave the
output file a little short due to buffer latency. The buffer size can
be adjusted using the '-b <buffered-frames>' option.
The tool also supoorts a different mechanism to time the recording
which uses the audio progress via a notify signal. This should ensure
at least the requested duration is recorded The shorter the notify
interval the closer teh final size shoould be to the requested
duration. Use the '-d <interval-ms>' option to adjust the notify
interval.
$ record_time_signal -o wwv.wav -s 55 -d 15 -n 100
Non-default audio devices can be selected, use the '-I' option to list
the available input devices with an index number that can be used to
select the device using the 'R <device-number>' option.
Other options are available, use '-h' for details.
