GNOME Bugzilla – Bug 617223
[tags] Add tags for direction of capture and movement
Last modified: 2010-05-03 17:02:12 UTC
We could add tags for tagging direction of movement and capture (0 to 360 degrees). I propose: GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION (double from 0 to 360 degrees, 0 is geographic north, clockwise) GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION (same). Meanwhile, we could also have GST_TAG_GEO_LOCATION_MOVEMENT_SPEED (in m/s or km/h?) I don't care about this one, but as we add the movement direction we might also add the speed, right? I'll prepare a patch. FYI, those are used in exif (which xmp uses)
> GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION (double from 0 to 360 degrees, 0 is > geographic north, clockwise) This is the direction into which the camera is pointed? > GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION (same). Makes sense, but in what scenario is this interesting in a multimedia context? When snapshotting/filming out of a train window or something? Or just for completeness sake? > Meanwhile, we could also have > GST_TAG_GEO_LOCATION_MOVEMENT_SPEED (in m/s or km/h?) > > I don't care about this one, but as we add the movement direction we might also > add the speed, right? Agreed. I'd go for m/s, it seems more 'neutral' and natural. The DOP might also be of interest, as an indication how precise the lat/long/elev values are, but maybe that value is too GPS-specific?
(In reply to comment #1) > > GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION (double from 0 to 360 degrees, 0 is > > geographic north, clockwise) > > This is the direction into which the camera is pointed? Exactly > > > > GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION (same). > > Makes sense, but in what scenario is this interesting in a multimedia context? > When snapshotting/filming out of a train window or something? Or just for > completeness sake? Yes, I guess that's the scenario. I looked up those while browsing exif/xmp spec and thought we should get all those in one go. > > > Meanwhile, we could also have > > GST_TAG_GEO_LOCATION_MOVEMENT_SPEED (in m/s or km/h?) > > > > I don't care about this one, but as we add the movement direction we might also > > add the speed, right? > > Agreed. I'd go for m/s, it seems more 'neutral' and natural. This completes the movement direction. And I agree m/s is better. > > The DOP might also be of interest, as an indication how precise the > lat/long/elev values are, but maybe that value is too GPS-specific? Exif represents it as a Rational (fraction), wikipedia tells us that it mathematically defined [1], so it should be possible to have it. I'll do some further reading. http://en.wikipedia.org/wiki/Dilution_of_precision_(GPS)#Computation_of_DOP_Values
A brief non-technical info about DOP if someone is interested in it: http://www.poly-electronic.ch/dok-gps/gps_eometry.htm
Created attachment 159953 [details] [review] tags: Adds geo location direction tags Adds 3 new geo location tags involving direction and movement of capture. Those are: API: GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION API: GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION API: GST_TAG_GEO_LOCATION_MOVEMENT_SPEED Fixes #617223
Comment on attachment 159953 [details] [review] tags: Adds geo location direction tags >+ gst_tag_register (GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION, GST_TAG_FLAG_META, >+ G_TYPE_DOUBLE, _("geo location capture direction"), >+ _("indicates the direction the device is pointing to when capturing a " >+ " a media. It is represented as degrees in floating point " One " a" too many :)
Fixed. Module: gstreamer Branch: master Commit: d020295ae0ed79fe7db3628a5e0ee2158274cfa5 URL: http://cgit.freedesktop.org/gstreamer/gstreamer/commit/?id=d020295ae0ed79fe7db3628a5e0ee2158274cfa5 Author: Thiago Santos <thiago.sousa.santos@collabora.co.uk> Date: Thu Apr 29 21:57:15 2010 -0300 tags: Adds geo location direction tags Adds 3 new geo location tags involving direction and movement of capture. Those are: API: GST_TAG_GEO_LOCATION_CAPTURE_DIRECTION API: GST_TAG_GEO_LOCATION_MOVEMENT_DIRECTION API: GST_TAG_GEO_LOCATION_MOVEMENT_SPEED Fixes #617223