Audacity doesn’t make a very good surveillance recorder.
– As you discovered, there’s no good way (outside of SMPTE Time Code) to record time of day.
– We can’t do Rolling Recording (erase the old while you’re recording new).
– There’s no good way to custom Timed Recording. There’s Sound Activated Recording, but we can’t go into full record for a defined period.
– Audacity doesn’t Play Well With Others, so for best stability you can’t have any other applications running on the machine. This brings you immediately to buying a real Surveillance Recorder instead of trying to cross-purpose Audacity.
– Audacity doesn’t have guaranteed process integrity. Search the forum for “holes or gaps in my recording.”
– There’s no company here. It’s a bunch of volunteers and we can’t do law enforcement, traceable surveillance or certified evidence.
That’s not to say you can’t do this cheaply. Run a video camera watching a clock and recording the sound event. That may take you straight back to buying a surveillance system rather than trying to wing it.
thanks for your reply, Koz. I understand, this is not the purpose of audacity.
Actually, we are a bunch of glider pilots and want to monitor our frequency. The sound triggered recording would be perfect, if only we knew when it was triggered.
The next version of Audacity is due to be released around the end of the year, and has an option to automatically add the date and time to the name of newly recorded tracks. (The “start time” of the recording). The setting will be in: “Edit menu > Preferences > Recording” and the feature will be documented in the manual.
If you mean while it is recording, just look at the “Length”.
When writing to disk, the precision (granularity) of the time stamp depends on the file system.
NTFS (Windows) has a maximum (at best) resolution/ranularity of 100 ns.
FAT had a granularity of 2 seconds
For ext4 (Linux) it’s 1 ns
The new timestamp feature in Audacity 2.1.3 gives: hh-mm-ss
Date is as: yyyy-mm-dd
Date and time as: yyyy-mm-dd_hh-mm-ss