[OSM-talk] Announcing a controllable Audio player and synchronisation with continuous sound tracks in JOSM

[David Earl]

Today's JOSM build (549) contains some much improved audio handling.

In particular, you can now use your dictaphone to record one long 
continuous audio file while you're surveying, collect waypoints on your 
GPS, and then in JOSM synchronise the audio with the waypoints and play 
each from waypoint individually. This means you're not forever having to 
pause and restart recording while surveying, or listen to hours of heavy 
breathing when playing back.

Also, audio is now threaded, which means it can be controlled while
playing, so as well as playing directly from a waypoint, you can pause 
and resume, jump forward and back, and from one waypoint to the next or 
previous.

Most of this won't affect you if you don't use audio. But there is a
flag you can set if the extra menu offends you (see below).

Here's the changes to JOSM:

1. When you open a GPX file, it always did extract waypoints from the
file and turn them into markers in their own layer. If you now right
click on that marker layer you can "Apply Audio" to the layer. Choose a
WAV file(*) and the markers all become audio markers. (Previously you'd 
have needed a GPX file with audio links already set for the waypoints).

2. If your GPS selectively names trackpoints (rather than separate 
waypoints), these can now be turned into Markers as well. Use "Markers 
from Named Points" on the GPX layer. You can also set the advanced 
option "markers.namedtrackpoints" to true and this will happen 
automatically when GPX is opened (i.e. named trackpoints are treated 
like waypoints).(**)

3. You can play audio for the markers by clicking the marker (that is
unchanged) - but it starts at the distance in to the audio that the
marker is timed offset from the first marker. (If you click another
marker while playing, it jumps straight to the one you just clicked).

4. There is an Audio menu with some controls on it. Note that the period
(full stop) key is the play/pause key accelerator. If you just play, it
will play the audio for the first audio marker in the first marker 
layer. Press again to pause (or more likely press full stop) (it
may take up to 0.5sec to actually pause). Play again then resumes. Click
the marker again to play from that marker. Forward and back jump 10
seconds (or whatever value you set in the option
"audio.forwardbackamount" ***). And you can advance to the next or 
previous marker with those buttons. If you use these a lot, you will 
quite likely want to add the buttons to the toolbar to make a little 
player bar, using button preferences in the usual way.

5. You will want to synchronize with a marker. You can do this with any 
audio marker (e.g. if you did do a pause part way through so the sound 
track gets out of step), but usually it will be the first one - you 
would say "NOW" into your recorder at the same time as creating the 
waypoint on your GPS.

Then in JOSM, play the marker you want to sync on until you get to the
"NOW" and pause it. Then use right click on the marker layer and select
"Synchronize Audio". Then when you play a marker it will adjust the
playing position accordingly. So if when you got to making waypoint 54
you said "point 54: pub called Royal Oak on left", when you click on 
audio marker 54 it should play that phrase immediately.

There is a one second lead in (i.e. it starts a second earlier than the 
offset), but you can adjust this with "audio.leadin" (incuding negative 
amounts so the playing can skip a short interval after the waypoint, if 
you find it hard to start talking into the dictaphone).

6. Previously waypoints are named/numbered on the map, but when they
were displayed as audio, only the icon appeared. Now, if you set the
advanced setting "marker.buttonlabels" to true, it will also show you
the name/number, so you can relate to what you said into the dictaphone.

7. If you don't want to see the Audio menu at all, set
"audio.menuinvisible" to true.

8. One peculiarity of the previous behaviour was that if you clicked to
add a node on top of an audio marker it _also_ played the audio. It
still does (I thought about various alternative ways to activate the
marker, because you often want a node just where the marker is).
However, it no longer activates the audio (or image, or link marker) if
you mouse down outside the button. This means you can at least make your
node and then drag it into position on top of the marker icon without it
playing.


David


(*) What WAV files it plays is dependent on the Java Audio System. I
found that it won't play the 32-bit framed wave files that come out of
my Olympus Digital Voice Recorder. However, a conversion using Audacity
only takes a few seconds even on a long mapping session. The minimum
Java will play seems to be 8,000 samples per second with 8 or 16-bit
samples (the Olympus does 8,000 but with 32 bit floating point samples).
Maemo-recorder on my Nokia N810 was fine (though quiet, but that was a
microphone/recorder problem I think).

(**) Maemo-mapper on the Nokia N810 does this. It calls them a "mark"
(Track -> Insert Mark, or tap point context menu). It's a pain to do
that so I now have an adapted version which requires a prod anywhere on
the screen - which is great when riding a bike - even wearing gloves. If
anyone would like this, please ask. I want to try to get it integrated,
but I've not heard anything back from the Maemo-mapper development group.

(***) I'm not sure this is doing 10 seconds at the moment - I will look 
at this.