[josm-dev] Audio markers based on modified times (time stamps) of audio files

[David Earl]

Roy Wallace wrote:
> Hi,
> I have a question about the current state of audio mapping in JOSM.
> 
> I want to create several separate wav file recordings, and use the *modified
> times *of the wav files to associate them with the correct places in the gpx
> track - in the same way as photo mapping is done (except getting the
> modified time from the file instead of the EXIF data). I don't want to have
> to make waypoints on my GPS device.
> 
> Is this possible yet with JOSM? If not, please let me know if it is planned.
> If it isn't planned, I'd like to get involved :)


Yes, I implemented this a few weeks ago in response to a similar 
request. However, the original requester never got around to testing it 
so it is possible there are bugs in it - I could test it by setting time 
stamps artificially, but I don't have means to generate these in 
real-world cases.


> If it is meant to be possible, please help me work out what I'm doing
> wrong. Following is my attempt:
> 
> 1. Load JOSM (latest version, 1708)
> 2. Open gpx track (Timespan: Jun 28, 2009 4:40 AM - Jun 28, 2009 7:35 AM
> (2:54))
> 3. Right click on GPS Layer, select "Import Audio"
> 4. Choose wav file (modified time Sun 28 Jun 2009 17:22:22 EST)
 >
> JOSM then warns me that "Some waypoints with timestamps from before the
> start of the track or after the end were omitted or moved to the start."
> 
> An audio file marker is then created at the start of the track. This seems
> wrong, as the marker should be well and truly within the bounds of the track
> timespan (17:22 EST = 7:22 GMT, right? Which is within 4:40 - 7:35).

Err, no.

You're quoting the GPX in UTC (GMT) and the audio in EST, yes? So 17:22 
is 21:22 UTC, not 07:22, which isn't anywhere near 04:40 to 0735 the 
same day. Eastern Standard Time is four hours behind GMT (during 
summer), not 10 hours ahead.

(It's also possible mixing time zones has a bug, but the times don't 
look right to start with here).


> 
> The checked boxes in audio preferences are the following only:
> * Display the Audio menu
> * Display live audio trace.
> * Create non-audio markers when reading GPX
> * When importing audio, make makers from...
> * * Modified times (time stamps) of audio files.

That's the correct settings IIRC.

BTW, if your audio timestamps are being "invented" or adjusted 
programatically you need to consider that the modified time of the audio 
is that of the *end* of the recording (if using a clock in the recorder, 
it will naturally do this).

David