[OSM-talk] JOSM Audio Mapping - Technical Issues
david at frankieandshadow.com
Fri Jan 2 12:24:30 GMT 2009
I should also have said that the system *does* also handle multiple
files already if you modify the GPX file to refer to the relevant audio
files at the correct time stamps (as described in the help file).
A preprocessor to do this automatically would be very handy for people
who want to work in this way.
On 02/01/2009 12:17, David Earl wrote:
> JOSM Audio is designed to sync *continuous* audio with the GPX track.
> This means you don't have to fiddle with the recorder buttons every time
> you want a voice note, you can just leave it in a pocket; but nor do you
> have to listen to inordinate amounts of heavy breathing.
> See the JOSM help file at
> http://josm.openstreetmap.de/wiki/Help/HowTo/AudioMapping for details
> (or use Help while in JOSM, same thing).
> I too have an Olympus recorder. The clock on mine is about 0.15% out,
> which means that a continuous sound track can be many tens of metres out
> after an hour's recording, so make sure you at least check whether you
> need to calibrate (as described in the help). I guess the time stamps
> for multiple files will suffer from the same problem too unless the
> recorder sampling rate and the time stamps run off a different clock.
> Note that in the long play mode the Olympus recorder (well, my model, so
> I guess all of them) records 4 bit audio, so you'll need to convert it
> to 8-bit using Audacity or similar before it is usable in JOSM. This is
> quick and easy for one long file, but a bit tedious if you have to do it
> for many small files.
> It would be relatively simple to extend the existing functionality to
> also process a folder full of time-stamped WAV files, one for each GPX
> waypoint; but really it is much easier just to record one long session -
> easier to record, easier to preprocess and easier to handle in JOSM.
> Someone mentioned that someone has broken audio in a recent JOSM
> version. I haven't had a chance to check yet, but I have made no changes
> to the audio recently.
> On a bike, I suggest using a cheapo PC headset (with a bit of sponge
> over the mic) rather than the built-in mic as it is completely hands
> free then.
> On 01/01/2009 16:58, Gregory wrote:
>> I got a new olympus digital voice recorder for Christmas, which means I
>> have to use http://code.google.com/p/odvr/ to download the recordings to
>> my linux/ubuntu computer. Unfortunatly when downloading the wav files
>> the recorded date gets lost, but a table of the times can be displayed
>> on the command prompt.
>> How does JOSM Audio get the date/time of the wav files?
>> I tried changing the linux files atime and mtime (last accessed/modified
>> time), but the location marker for the audio does not change. Is it
>> using the ctime (created time)? I can not change the ctime and it gets
>> set to the time the files were downloaded off the voice recorder.
>> I have filled an issue with the odvr downloader, but I want to confirm
>> that it is the ctime that needs to be right for JOSM. I was recording
>> ~2sec comments as I passed a location, so I have a trip with 60
>> recordings waiting to be mapped.
>> My final idea is maybe I could make a JOSM plugin (now I've learnt some
>> Java) that takes a fixed-width txt table of time stamps and names, and
>> match the times to an open gpx file to create waypoints. This would mean
>> I have to open audio files outside of josm, but at least I would know
>> where they were recorded. Such a plugin may help people with other media
>> problems, ao I wonder has something along those lines already been done?
>> I've been told audio mapping is more amazing than photo mapping, and it
>> would be ideal cycling in these cold winter months. Sadly it's not going
>> to well yet, so I hope to get this sorted.
>> Gregory Marler
>> talk mailing list
>> talk at openstreetmap.org
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