Talk:JOSM/Plugins/VideoMapping

It has been proposed that this page or section be merged with video mapping. (Discuss)

Some thoughts

I have been thinking about video mapping myself and will just share my thoughts here, in the hope that they will be useful... I have moved some of the content to Video mapping (basically, all that is not specific to the JOSM plugin will eventually end up there).

Dealing with long meaningless sections

When driving along a highway, many sections will not contain any data that is of interest.

In order to identify these sections, some kind of marker is needed. Possibilities are:

• GPX trackpoints
• Geotagged photos (which I use as a substitute for the above, as I make tracks with navit, which does not support trackpoints)
• Beginning/end of track (in the past, I have also used that as a substitute for missing trackpoints)

Well it allways depends how good the area is mapped allready. So if it's blank there are a lot of things to see (structure, traffic signs, parkingplaces,...) --!i! 12:39, 31 May 2010 (UTC)

Alternatives to Video

As an alternative to video, using a still image camera to take pictures at fixed intervals may overcome some shortcomings of video cameras: Higher resolutions may become possible; capacity shortcomings can be compensated for by choosing longer intervals between images (professionals work this way, taking photos at 1-second intervals). It might be possible to later assemble the still images into a video stream, or enable the JOSM plugin to process them in a similar way.

I'll add a window with multiple videos that play synced and parallel. We will see if there is enough space for all of them :) --!i! 12:39, 31 May 2010 (UTC)

Analyzing data

The above considerations result in a few requirements for the plugin:

• Correlation with GPX data
• Indicator on the map, showing the geolocation related to the current video position (i.e. the marker will run along the GPX track as the video is played)
• Support for multiple videos (e.g. from multiple cameras)
• Jumping to a video position by clicking on the map (important for implementing markers). Consider a context menu that opens when clicking a point in the map which offers a selection of available footage (take into account that tracks may cross or the same road may be followed twice). The options for a single point may read like:

* Video001, 0:26:33
* Video001, 0:45:42
* Video002, 0:26:41
* Video002, 0:45:50

Groundwork already done elsewhere

Correlation of photos to GPX tracks (by timestamp) is already implemented in JOSM plugin AgPifoJ (now part of the JOSM core and no longer a separate plugin). It needs to be configured with the "drift" between GPS time and the camera clock; this is done by taking a picture of the receiver showing GPS time and comparing time displayed to the EXIF timestamp. Something similar could be done with a video: film the GPS clock and store something like "position 0:26 of the clip corresponds to 15:35:11 GPS time".

Yes for the sync you can navigate in both, the GPS and video timelines separately. Then you can move in the GPS track using a 'jump to xx:yy:zz' function to go to the time, you see in the video. Otherwise you have to look for significant points (turns, houses,...) --!i! 12:39, 31 May 2010 (UTC)

There are already some audio mapping features in JOSM (though I never looked into them in detail). They also do some kind of georeferencing; the interesting part is that they also deal with data which has a certain duration. This feature offers, as far as I know, a marker running along the GPX track as the audio file is played. Stanton 13:39, 30 May 2010 (UTC)

Sry both are part of the core, a plugin has limited features. Mostly it seems that they are to limited :( I will try it on my own.... --!i! 12:39, 31 May 2010 (UTC)

By now they are, but photo mapping started out as a plugin (AgPifoJ) and got added to the core only recently. So most of the things that the photo mapping component does should be within the possibilities of a plugin. As for the audio mapping feature, I'm not so sure if that was a core component from the beginning, at least as of December 2009 it was in the core. Stanton 20:19, 10 June 2010 (UTC)

Just a bit of history: there was photo mapping capabilities in JOSM before AgPifoJ, but the latter turned out more capable and more stable. But the older functionality had started as a plugin, too. Audio mapping was there already in 2007 and as far as I have seen, was implemented before any (reasonable) capability for plugins. Alv 06:44, 11 June 2010 (UTC)

Problems

The Plugin seems to crash with every type of video. Do I miss anything, or does it only run on non-windows-systems? Are there any requirements?

Hi due tue a hardware crash and no other system I didn't had the possibility to do any deployment testing. If you give me one or two weeks I will try to get it working/testing on other systems --!i! 23:36, 3 July 2011 (BST)

I have the same "problem": plugin crashes immediately. What is missing from a documentation pov is: vlcj and videolan version required. And (this might be the reason for the crashes): how are you supposed to associate the video with a specific track? I can defintely help with getting the plugin to run on W7 if needed. --simon

There seems to be a new build, however the behaviour hasn't changed. --simon

Sorry, wont get time this month :( --!i! 21:14, 19 July 2011 (BST)

Hi! I'd love to test on Linux (Kubuntu 64 bits) and help debug! I've read the bachelor thesis on videomapping. I have acquired one FlyCamOne2 (capable of taking videos or pictures every 4 seconds), have ordered a second cam and plan to use 7 of them (360°) with a device to synchronise them with GPSr and electronic compass. Mayeul 22:12, 29 August 2011 (BST)

Sounds interesting, but cause of a massive lack of time, I'm currently unable to do anything on the plugin. But I will definitly continue the development (hopefully this year) --!i! 08:12, 30 August 2011 (BST)

The plugin has at least two (undocumented) issues that cause it to crash and burn depending on the input GPX track:

• it assumes a constant trackpoint recording interval

• it assumes that interval to be one second

The version in the svn doesn't compile against the current JOSM so I haven't fixed the issue(s) yet. BTW is there a place to submit bug reports?

SimonPoole 16:07, 28 March 2012 (BST)