GstTagList

[Tim Müller]

On Tue, 2014-02-25 at 06:52 -0800, Alice Wonder wrote:

> Am I correct in understanding that for a GStreamer application (e.g.
> rhythmbox) to read/write a metadata tag, it needs to be defined in
> gst/gst.h?

Well, not exactly, but somewhat.

Some basic/common tags are defined in GStreamer core:
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstTagList.html

Some more tags are defined in gst-plugins-base's ligbsttag:
http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-libs/html/gst-plugins-base-libs-gsttag.html

It's possible for applications and elements to register custom tags in
addition to the pre-defined ones.

However, if you want to read/write specific tags with existing elements,
these elements need to have an internal mapping to map the tags to a
GStreamer tag. To support additional tags, those mappings would need to
be updated in the source code for existing tag reading/writing elements.

For some tags, generic support is also available via the
GST_TAG_EXTENDED_COMMENT tags (key=value basically).


> If so, where does one make a case for additions?

bugzilla: http://gstreamer.freedesktop.org/bugs/

Cheers
 -Tim

-- 
Tim Müller, Centricular Ltd - http://www.centricular.com