[josm-dev] Audio user interface

[Chris Morley]

David Earl wrote:
> I think it ought to be possible to drag the play head, and had 
> wondered about doing that. What I don't think I can do, without 
> introducing a mode is to click anywhere on the track to start playing 
> there. 
You wouldn't want to do that, JOSM already has three modes too many.

>> Sychronization is currently complicated and difficult to remember. With 
>> this proposal, the audio would be started and paused at the place you 
>> said NOW. The orange marker would then be SHIFT dragged to the 
>> geographical position that NOW corresponds to. It is is easy to 
>> understand "I *was* here when I said this", with the SHIFT implying 
>> coercion.
> 
> I'm not convinced that's so much easier. I think using the play head, 
> which follows from the above, makes sense, but I'm not sure about using 
> a modifier, as you have to remember that, as opposed to a menu entry - 
> but they needn't be mutually exclusive I suppose. 

I see the disadvantage of having to remember the modifier. However, 
after an ordinary play head move you usually want to start playing and 
making it happen as part of the move would be nice. But this is not 
possible if the modifier is not used for synchronization, since then you 
need the audio to be paused while you select the menu item. See below 
for another reason for using the modifier.

There seems to be a problem when using audio files that run for only 
part of the gpx file.

I have a morning audio recording and an afternoon recording but only
a single GPS track, because you have to do that with Garmin devices. I
can't synchronize the afternoon recording because the documented method
relies on accessing the geographical position of the synchronization
point by running the audio until the playhead reaches it. If the 
afternoon recording is shorter than the morning recording, it never 
does. Maybe I have missed something, but all I have managed to do is to 
work around the problem by splitting the gpx file - which is not a very 
nice long term solution.

It could be quite common to want to record comments on only a part of a 
gpx track, so there should't be any restrictions on where the 
synchronization point can be, or on the length or number of associated 
audio files. (One loaded at a time is ok). Using SHIFT dragging of the 
orange print head for synchronization wouldn't have a problem here.

Another thing that confused me was that if you start playing by clicking 
on one of the automatic audio way-points that is before the start of the 
audio, then it plays from the beginning of the audio, i.e. 
unsynchronized. This behaviour is necessary for the synchronization 
process, but if it wasn't noticed it could lead incorrect data. Perhaps 
when this occurs the user could be alerted by having a different colour 
for the play head, which would also be used before synchronization.

Short audio files can also lead to automatic audio way-points after the 
recording, which just give an error message when clicked. So there are 
three types of automatic audio way-points: ones which usually don't give 
you any useful audio, ones which mislead you and ones which give an 
error message. I think it is time to get rid of them.

Synchronization by dragging the play head could also involve moving into 
the regions before and after the audio and so it is necessary for the 
process to be an atomic one to avoid the error message. That is, you 
cannot easily use an additional action from a menu to do the 
synchronization; the SHIFT modifier method is better.

Chris