Re: How to access geotag information?
Hi, i just realized that we are talking about completely different things when we say geotagged. I am relating to GPS positions. You seem to relate to place names. I just learned that the n900 does not write GPS tags. Correct? Unfortunately that completely spoils the idea to use maep to display these. Converting GPS positions into place names and back to coordinates will likely cause most images to show up pretty far from their real location and even worse will make them all show up at the same place. Is there a way to enable real GPS tagging? Is there any reason why this isn't happending? It's so obvious that just i didn't expect this not to be there. Till Am Montag 11 Januar 2010 schrieb Ivan Frade: Hi, El vie, 08-01-2010 a las 20:45 +0100, ext Till Harbaum / Lists escribió: Hi, Am Freitag 08 Januar 2010 schrieb Ivan Frade: see it when i arrive there). This will be supported in tracker 0.7 (ready to play with on desktop), but not in 0.6/fremantle. Using tracker 0.6 limited to images is a start. Do you have example code somewhere? I have never worked with tracker before. We have some (basic) documentation here: http://live.gnome.org/Tracker/Documentation/RDF-Query Tracker is a daemon visible in DBus. In python, connect to the daemon directly (an example in my own pet-project [1]). In C, use libtracker-client (some examples in MAFW's tracker backend). There should be some libtracker-client gtk-doc documentation, but it looks like library.gnome.org only contains the last unstable version (0.7). This is useless for you, the API in 0.7 is _completely_ different from 0.6 API. Don't get confused with that. The properties you can use in your queries are defined here: http://git.gnome.org/browse/tracker/tree/data/services?h=tracker-0.6 You can also monitor dbus while using the image-viewer to see some queries flying. Regards, Ivan [1] https://garage.maemo.org/plugins/ggit/browse.php/?p=mussorgsky;a=blob;f=src/tracker_backend.py;h=e956f38668066423fa9538a1cb69a4082f776fa8;hb=9d71d07b572bdf50114484b28a0e188d742fcdfc ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Hi, El vie, 08-01-2010 a las 20:45 +0100, ext Till Harbaum / Lists escribió: Hi, Am Freitag 08 Januar 2010 schrieb Ivan Frade: see it when i arrive there). This will be supported in tracker 0.7 (ready to play with on desktop), but not in 0.6/fremantle. Using tracker 0.6 limited to images is a start. Do you have example code somewhere? I have never worked with tracker before. We have some (basic) documentation here: http://live.gnome.org/Tracker/Documentation/RDF-Query Tracker is a daemon visible in DBus. In python, connect to the daemon directly (an example in my own pet-project [1]). In C, use libtracker-client (some examples in MAFW's tracker backend). There should be some libtracker-client gtk-doc documentation, but it looks like library.gnome.org only contains the last unstable version (0.7). This is useless for you, the API in 0.7 is _completely_ different from 0.6 API. Don't get confused with that. The properties you can use in your queries are defined here: http://git.gnome.org/browse/tracker/tree/data/services?h=tracker-0.6 You can also monitor dbus while using the image-viewer to see some queries flying. Regards, Ivan [1] https://garage.maemo.org/plugins/ggit/browse.php/?p=mussorgsky;a=blob;f=src/tracker_backend.py;h=e956f38668066423fa9538a1cb69a4082f776fa8;hb=9d71d07b572bdf50114484b28a0e188d742fcdfc ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Till Harbaum / Lists on 01/07/2010 10:15 AM wrote: - We'll have to scan all files in every geotag aware app If you want to create some sort of standard database for holding GPS metadata for any file type then you have to write it. - This consumes much CPU power Reading a file is hardly CPU intensive. - This takes a very, VERY long time Not on an SSD unless you have billions of files. - This does not work with MP3/WAV/PNG/GIF/AVI/... Quite right. Why do you expect GPS information to be available for these files? Who told you to expect GPS data from those file types? - This information can hardly be shared between different apps The standard for JPEG type files is to use EXIF for any and all metadata. Any app should and can support reading EXIF. - My app has to cache/store this information for all media files to not be forced to re-scan everything everytime it's being started I think you need to re-think what your goal is. ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Hi, thank for you for your reply. Am Donnerstag 07 Januar 2010 schrieb Michael Cronenworth: - This consumes much CPU power Reading a file is hardly CPU intensive. Reading thousands of files is. I really don't have much media stored on my n900, but it's already 400 mp3 files, 150 jpegs and 40 avi videos. Scanning them for tags aready would take a long time and even worse would consume lots of CPU (and thus battery) power. - This takes a very, VERY long time Not on an SSD unless you have billions of files. Reading several thousand media files does not take long? You'll have to scan all oif them, even if only a fraction of them actually contains geotags as you don't know which the ones with geotags are before you actually search for them. - This does not work with MP3/WAV/PNG/GIF/AVI/... Quite right. Why do you expect GPS information to be available for these files? Who told you to expect GPS data from those file types? Why should i assume that i can savely ignore them if they all may actually contain geotags? Why should i be sure that e.g. maemo-recorder nor any other app puts geotags into the wav files it stores? - This information can hardly be shared between different apps The standard for JPEG type files is to use EXIF for any and all metadata. Any app should and can support reading EXIF. But then every single app has to scan every single file. That's awful. I think you need to re-think what your goal is. That's sad as it really limits the usage of geotags. The right solution would sure be to let tracker handle this as it's the purpose of tracker to index the disk for media files and to provide meta information to all apps interested in this. Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Hi, Am Donnerstag 07 Januar 2010 schrieb Michael Cronenworth: How do i access geotags? With libexif. GPS coordinates are in the EXIF data. This only works for jpeg images which are only a fraction of media files stored on an n900. I was fearing to get some answer like this. This has so many disadvantages: - We'll have to scan all files in every geotag aware app - This consumes much CPU power - This takes a very, VERY long time - This does not work with MP3/WAV/PNG/GIF/AVI/... - This information can hardly be shared between different apps - My app has to cache/store this information for all media files to not be forced to re-scan everything everytime it's being started I am afraid this will mean that such a project doesn't make much sense. Thanks, Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
On Thu, 2010-01-07 at 20:50 +0100, ext Till Harbaum / Lists wrote: Hi, I think you need to re-think what your goal is. That's sad as it really limits the usage of geotags. The right solution would sure be to let tracker handle this as it's the purpose of tracker to index the disk for media files and to provide meta information to all apps interested in this. Yes, tracker should do it. Fortunately, tracker can be extended to index all kind of information. CC'ing Ivan Mr. Tracker Frade here... -Kimmo Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Michael Cronenworth wrote: Till Harbaum on 01/07/2010 06:30 AM wrote: How do i access geotags? With libexif. GPS coordinates are in the EXIF data. I didn´t really look into this, but at least for image files tracker seems to be prepared to handle geo tags. Not sure if this functionality is available in reality, but have a look at the file /usr/share/tracker/services/image.metadata There are two properties that look interesting: Image:Location and Image:Sublocation Anyways, it´s just a guess. Conny ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Cornelius Hald on 01/08/2010 05:02 AM wrote: Anyways, it´s just a guess. That's for images only. Till wants it for *all* file types. ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Kimmo Hämäläinen on 01/08/2010 04:58 AM wrote: Yes, tracker should do it. Fortunately, tracker can be extended to index all kind of information. CC'ing Ivan Mr. Tracker Frade here... GPS data is stored in tracker for images only. Till wants GPS data for *all* file types. ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Hi, Am Freitag 08 Januar 2010 schrieb Michael Cronenworth: GPS data is stored in tracker for images only. Till wants GPS data for *all* file types. If the tracker really already has basic geotagging support, then i think it's the only acceptable solution to use it, even if this is currently limited to images only. This sounds like a classic chicken/egg problem and as long as only the image viewer supports geotagging, noone will bother to extend the tracker for other formats. So if tracker can provide geotagging info i'd be more than willing to use that. Perhaps e.g. the maemo-recorder guys can be convinced to tag their files and this might in turn cause someone to extend the tracker functionality to support geotags in sound files ... I really REALLY think tracker is the only useful way to deal with geotags especially in a mobile device where indexing may really be expensive with respect to CPU power and battery. What's the tracker guru's opinion? Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Hi, El vie, 08-01-2010 a las 15:35 +0100, ext Michael Cronenworth escribió: Cornelius Hald on 01/08/2010 05:02 AM wrote: Anyways, it´s just a guess. That's for images only. Till wants it for *all* file types. In Fremantle, tracker 0.6 can store the location of Images (basically the geotags the user set in the image viewer). Those properties contain text, so you need to use the location API to turn them into coordinates for your map application. About other media types... there is no other format containing location, so tracker cannot fill that information by itself. Our idea for the future is that _applications_ can set location values for the files (e.g. a shopping-list note in the supermarket, so i can see it when i arrive there). This will be supported in tracker 0.7 (ready to play with on desktop), but not in 0.6/fremantle. Some remarks to the previous comments in the thread: 1) EXIF is not the only format for metadata in images. There is XMP or IPTC, and you need a hierarchy to choose between them, and handle broken files and ... well, don't underestimate the problem 2) The idea of scanning and monitoring the filesystem means basically to duplicate the functionality of tracker (and probably the code ;)) 3) Scanning and reading files is not CPU expensive, but needs a lot of IO, and IO is a very precious resource. Regards, Ivan ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Hi, I was answering the previous email :) Few more comments. El vie, 08-01-2010 a las 16:43 +0100, ext Till Harbaum / Lists escribió: Hi, Am Freitag 08 Januar 2010 schrieb Michael Cronenworth: GPS data is stored in tracker for images only. Till wants GPS data for *all* file types. I really REALLY think tracker is the only useful way to deal with geotags especially in a mobile device where indexing may really be expensive with respect to CPU power and battery. We have two problems: 1) Who set the location information? Responsibility of applications. 2) Where should that information be stored? In tracker. but ... 1) No application is really setting location information except the image viewer (and only for images) 2) Tracker 0.6 cannot store efficiently that information. We could try to add a File:Location property, so you could set location for everything known by tracker, but it is going to be very very inefficient. This will be fixed in 0.7 . Regards, Ivan ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
RE: How to access geotag information?
GPS data is stored in tracker for images only. Till wants GPS data for *all* file types. I really REALLY think tracker is the only useful way to deal with geotags especially in a mobile device where indexing may really be expensive with respect to CPU power and battery. We have two problems: 1) Who set the location information? Responsibility of applications. 2) Where should that information be stored? In tracker. but ... 1) No application is really setting location information except the image viewer (and only for images) 2) Tracker 0.6 cannot store efficiently that information. We could try to add a File:Location property, so you could set location for everything known by tracker, but it is going to be very very inefficient. This will be fixed in 0.7 . It would be preferable to also store the lat/lon information so that applications could use that if they see fit (e.g. map apps) as well as the pre-reverse geocoded location name, otherwise there's additional overhead and severe inaccuracy of the geocoding. From a quick websearch I can see that video can and is geocoded at least (either once uploaded, or for e.g. some Sony camcorder with a built-in GPS), so adding support for geocoded videos would be nice. I can also envision other files adding geocoding metadata about themselves to the tracker database, even if the file itself doesn't support internal geocoding metadata (is that possible, I guess it should be?) so adding a geotag field (or fields I hope for name and lat/lon) would be a nice, cool and future proof thing to do (but yeah it will waste some space for files that don't use it, but probably not much, though I've not looked at the db so I don't know for sure). Anyway I think it's a shame we don't make more use of our geo-information and the ability to enable it in general on the N900 - the IM app doesn't report actual location data which is a real shame (and hence my interest in using Google's Latitude instead), contacts can contain addresses but not more accurate lat/lon, etc. Cheers, Simon ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
On Fri, 2010-01-08 at 18:19 +0200, Ivan Frade wrote: Hi, but ... 1) No application is really setting location information except the image viewer (and only for images) As far as i know, Camera is also setting location information. The GPS coordinates are stored in EXIF and the reverse geocoding strings are in XMP. The location metadata is set for both, images and videos. -- Javier Fernández García-Boente http://blogs.igalia.com/jfernandez/ www.igalia.com signature.asc Description: This is a digitally signed message part ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
RE: How to access geotag information?
My gut feeling is that as we move forward, geotag type information really belongs with the file information. e.g. I would love to have the ability to stat a file to find out the geolocation where a file was created as well as the time that the file was created. Of course, that is a very big change right down at the OS level, so until file systems change to include something like geolocation of creation, Till's approach sounds pretty interesting. Aldon 41.3324, -72.9882 -Original Message- From: maemo-developers-boun...@maemo.org [mailto:maemo-developers-boun...@maemo.org]on Behalf Of Till Harbaum / Lists Sent: Friday, January 08, 2010 10:43 AM To: Michael Cronenworth Cc: maemo-developers@maemo.org Subject: Re: How to access geotag information? Hi, Am Freitag 08 Januar 2010 schrieb Michael Cronenworth: GPS data is stored in tracker for images only. Till wants GPS data for *all* file types. If the tracker really already has basic geotagging support, then i think it's the only acceptable solution to use it, even if this is currently limited to images only. This sounds like a classic chicken/egg problem and as long as only the image viewer supports geotagging, noone will bother to extend the tracker for other formats. So if tracker can provide geotagging info i'd be more than willing to use that. Perhaps e.g. the maemo-recorder guys can be convinced to tag their files and this might in turn cause someone to extend the tracker functionality to support geotags in sound files ... I really REALLY think tracker is the only useful way to deal with geotags especially in a mobile device where indexing may really be expensive with respect to CPU power and battery. What's the tracker guru's opinion? Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Hi, Am Freitag 08 Januar 2010 schrieb Ivan Frade: About other media types... there is no other format containing location, so tracker cannot fill that information by itself. In this web site you can download wav files which claim to be geotagged: http://www.freesound.org/samplesViewSingle.php?id=73423 That's why i thought the maemo-recorder could do the same. see it when i arrive there). This will be supported in tracker 0.7 (ready to play with on desktop), but not in 0.6/fremantle. Using tracker 0.6 limited to images is a start. Do you have example code somewhere? I have never worked with tracker before. 3) Scanning and reading files is not CPU expensive, but needs a lot of IO, and IO is a very precious resource. Whatever the limit is: You don't want to do this in every single app. Reards, Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
How to access geotag information?
Hi, i am planning to add a feature to Maep so that it displays small thumbnails of geotagged media data. How do i access geotags? I suppose the correct way to access any media files is to go via tracker. Are there any examples to request geoinformation from tracker? A little googling reveals many pages saying that tracker doesn't index geotags. Is this true? What is the correct way to get geotags of all media stored on the device? It sure doesn't make much sense to ask tracker for a list of all media and than try to extract geotags from them. This would take forever on a big media collection. Regards, Till ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
Re: How to access geotag information?
Till Harbaum on 01/07/2010 06:30 AM wrote: How do i access geotags? With libexif. GPS coordinates are in the EXIF data. ___ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
