[gst-devel] help! questions on gstreamer and tagging

[Tim-Philipp Müller]

On Mon, 2008-08-11 at 16:33 -0400, Fred Warren wrote:

Hi,

> 1. I gather that gstreamer can get meta data from media files. Can
> someone provide an example(pygst, please) on how to get metadata from
> files as a reference point?

There should be some in the gst-python source code (examples directory),
check out gstfile.py there.

> 2. How can you get specific meta data(like just the duration) only?

The duration you have to query from the pipeline once playbin or the
pipeline is in PAUSED or PLAYING state (you can output to a fakesink if
you just want to retrieve this information without actually outputting
any video or audio). Most of the other meta data you can get from the
tag messages posted on the pipeline's bus.

> 3. What is its advantage over something like lib-id3? Can it do
> everything lib-id3 can?

The advantage is that GStreamer metadata extraction works for a lot of
different formats and you can handle the metadata processing in the
exact same way regardless of the format. I don't know how GStreamer's
id3demux compares to libid3 feature-wise (esp. since there are probably
about a hundred different libraries called libid3 or id3lib), but it
seems to be good enough for the most common use cases. If you find that
we're missing something which you need, file a feature request in
bugzilla and we'll fix it (eventually at least).

 Cheers
  -Tim