gstreamer/ext/metadata
Benjamin Otte 33c2f5fb01 Add -Wwrite-strings
and fix its warnings
2010-03-22 13:16:33 +01:00
..
.gitignore
gstbasemetadata.c Add -Wwrite-strings 2010-03-22 13:16:33 +01:00
gstbasemetadata.h Fix gtk-doc warnings. Also don't misuse api-doc comments for normal comments. 2008-06-18 06:31:13 +00:00
gstmetadata.c Add -Wmissing-declarations -Wmissing-prototypes to configure flags 2010-03-21 21:39:18 +01:00
gstmetadatademux.c Add -Wwrite-strings 2010-03-22 13:16:33 +01:00
gstmetadatademux.h Add -Wmissing-declarations -Wmissing-prototypes to configure flags 2010-03-21 21:39:18 +01:00
gstmetadatamux.c Add -Wwrite-strings 2010-03-22 13:16:33 +01:00
gstmetadatamux.h Add -Wmissing-declarations -Wmissing-prototypes to configure flags 2010-03-21 21:39:18 +01:00
Makefile.am Don't install static libs for plugins. Fixes #550851 for -bad. 2008-11-04 12:42:30 +00:00
metadata.c GstAdapter is not a GstObject and should be freed with g_object_unref() 2009-08-31 13:14:02 +01:00
metadata.h
metadata_mapping.htm ext/metadata/: Add mapping of format and mime type to xmp. 2008-10-03 05:57:58 +00:00
metadataexif.c metadata: don't check for NULL when calling g_free. 2010-03-11 11:29:16 +02:00
metadataexif.h metdata: more logging and code cleanups 2009-03-22 21:02:45 +02:00
metadataiptc.c metadata: don't check for NULL when calling g_free. 2010-03-11 11:29:16 +02:00
metadataiptc.h metdata: more logging and code cleanups 2009-03-22 21:02:45 +02:00
metadatamuxjpeg.c metadata: use a non-DEFAULT proper debug category in helper files 2010-02-05 10:21:19 +01:00
metadatamuxjpeg.h
metadatamuxpng.c metadata: use a non-DEFAULT proper debug category in helper files 2010-02-05 10:21:19 +01:00
metadatamuxpng.h
metadataparsejpeg.c metadata: use a non-DEFAULT proper debug category in helper files 2010-02-05 10:21:19 +01:00
metadataparsejpeg.h
metadataparsepng.c metadata: use a non-DEFAULT proper debug category in helper files 2010-02-05 10:21:19 +01:00
metadataparsepng.h
metadataparseutil.c metadata: use a non-DEFAULT proper debug category in helper files 2010-02-05 10:21:19 +01:00
metadataparseutil.h Add -Wredundant-decls flag 2010-03-22 12:05:59 +01:00
metadatatags.c metadata: Remove _XMP_GEO_* tags 2010-03-11 15:46:21 -03:00
metadatatags.h metadata: Remove _XMP_GEO_* tags 2010-03-11 15:46:21 -03:00
metadatatypes.c metadata: don't check for NULL when calling g_free. 2010-03-11 11:29:16 +02:00
metadatatypes.h
metadataxmp.c metadata: Remove _XMP_GEO_* tags 2010-03-11 15:46:21 -03:00
metadataxmp.h metdata: more logging and code cleanups 2009-03-22 21:02:45 +02:00
README configure.ac 2008-10-06 16:01:49 +00:00
TODO metadata: update bug status 2010-03-11 10:36:27 +02:00

### design proposal for metadata mux and parser ###

## use cases ##

1- Create metadata

[ App send tag events to the pipeline ]
  ||               /\
  ||               ||
  ||          jpegenc send tag messages like (width, height and compression info)
  ||               ||
  \/               ||
+---------+    +---------+    +-------------+    +----------+
| v4l2src | -> | jpegenc | -> | metadatamux | -> | filesink |
+---------+    +---------+    +-------------+    +----------+

* elements like videoscale should also send (width and height tags)
* should metadatamux get info from caps (width and height) and use if not receive a event with such tags?


2- View metadata

+---------+    +---------------+    +---------+    +-------------+
| filesrc | -> | metadataparse | -> | jpegdec | -> | xvimagesink |
+---------+    +---------------+    +---------+    +-------------+

or

                    +--> whole chunk send as event to next element
                    |
+---------+    +---------------+    +----------+
| filesrc | -> | metadataparse | -> | fakesink |
+---------+    +---------------+    +----------+
                    ||
                    \/
               1- individual tags send as messages (what about not mapped tags??)
               2- whole chunk send as message (probably the application will ignore this)

* in any case metadataparse strips out metadata chunks (different from current implementation)


3- Modify (add, change, delete tags)

                    +--> whole chunk send as event to next element -- ... --+
                    |                                                       |
                    |                                                       V
+---------+    +---------------+                                     +-------------+    +----------+
| filesrc | -> | metadataparse | --------------- ... --------------> | metadatamux | -> | filesink |
+---------+    +---------------+                                     +-------------+    +----------+
  /\                ||
  ||                \/
  ||           1- individual tags send as messages (what about not mapped tags??) ==============\\
  ||           2- whole chunk send as message (probably the application will ignore this)       ||
  ||                                                                                            ||
[ App send tag events to the pipeline ] <=======================================================//

* metadataparse strips out metadata chunks (different from current implementation)
* application receives individual tag messages (what about not mapped ones?)
  * the application only send events back to the pipeline for the tags the application wants to modify or keep.
    The tags not sent will not be included in metadata chunks
* the metadatamux modify the whole chunk event received before to just keep the individual tags sent by application
* the metadatamux could have a property to say if it should remove or keep tags not sent by application. 

Obs: By looking at the proposed design (1- view and 2- modify) seems that the metadataparse and metadatamux should not know about mapped tags.
     Only the application map the tags to/from metadata specific format. This is because, if you notice, only tags sent by application will be keep
     on new file.


4- Convert (for example from jpeg to png)

                      +--> whole chunk send as event to next element -- ... --+
                      |                                                       |
                      |                                                       V
+---------+    +---------------+                                        +-------------+    +----------+
| filesrc | -> | metadataparse | -> | jpegdec | -> ... -> | pngenc | -> | metadatamux | -> | filesink |
+---------+    +---------------+                                        +-------------+    +----------+
  /\                ||
  ||                \/
  ||           1- individual tags send as messages (what about not mapped tags??) ==============\\
  ||           2- whole chunk send as message (probably the application will ignore this)       ||
  ||                                                                                            ||
[ App send tag events to the pipeline ] <=======================================================//

* in this case the application set the metadatamux property to always keep the tags by default (application don't not need to send tag events)
* metadatamux needs additional smartness to check what tags still does make sense (some from original jpeg may not make sense anymore)
* if the image is resized, the videoscale should send messages to the application with new width (in the same way pngenc should also) and the
  application could send width and height tag events to the pipeline
* should metadatamux get info from caps (width and height) and use if not receive a event with such tags?


Testing
GST_DEBUG="*:2,metadata*:4" 
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=66.1,geo-location-longitude=22.5,geo-location-elevation=10.3" ! metadatamux ! filesink location="meta_test_ppp.jpeg"
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=66.1,geo-location-longitude=22.5,geo-location-elevation=-10.3" ! metadatamux ! filesink location="meta_test_ppn.jpeg"
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=66.1,geo-location-longitude=-22.5,geo-location-elevation=10.3" ! metadatamux ! filesink location="meta_test_pnp.jpeg"
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=66.1,geo-location-longitude=-22.5,geo-location-elevation=-10.3" ! metadatamux ! filesink location="meta_test_pnn.jpeg"
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=-66.1,geo-location-longitude=22.5,geo-location-elevation=10.3" ! metadatamux ! filesink location="meta_test_npp.jpeg"
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=-66.1,geo-location-longitude=22.5,geo-location-elevation=-10.3" ! metadatamux ! filesink location="meta_test_npn.jpeg"
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=-66.1,geo-location-longitude=-22.5,geo-location-elevation=10.3" ! metadatamux ! filesink location="meta_test_nnp.jpeg"
gst-launch videotestsrc num-buffers=1 ! jpegenc ! taginject  tags="geo-location-latitude=-66.1,geo-location-longitude=-22.5,geo-location-elevation=-10.3" ! metadatamux ! filesink location="meta_test_nnn.jpeg"

exiv2 -pt pr meta_test_ppp.jpeg | grep "Exif.GPSInfo"
exif meta_test_ppp.jpeg

gst-launch -t filesrc location="meta_test_ppp.jpeg" ! metadatademux ! fakesink