Hi,  Try this in your callback function:     myInfo = gst_caps_to_string(caps);     g_print(myInfo); You will see something like that for a video pipeline in your console:   video/x-raw-rgb, bpp=(int)16, depth=(int)16, width=(int)640, height=(int)464, framerate=(fraction)25/1, pixel-aspect-ratio=(fraction)1/1, red_mask=(int)63488, green_mask=(int)2016, blue_mask=(int)31, endianness=(int)1234 hope this help you, Erwan Masson <div>2007/4/13, Vincent Torri <<a href="mailto:vtorri@univ-evry.fr">vtorri@univ-evry.fr</a>>:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hey, I wrote a prog that extracts (some of ?) those data from any multimedia file (audio or video) 2 years ago. I've attached it. Basically: 1) I build a basic pipeline : filesrc ! decodebin 2) I set the pipeline to the PAUSED state. 3) Each time a stream is found, I get its properties. The program has 2 parts : 1) a lib one, that stores the properties 2) a binary one that uses the lib part. I've made a CLI one (no gui) and 3 gui, one with gtk. You'll have to disable the other gui to compile the progs, iirc (or maybe they'll not be built as I think that you don't have those toolkits. I can't remember). That means that you can even use directly the lib part and integrate it to your prog if you find it usefull. There is a GNU Copying licence, but I think that it has been automatically created. I didn't intend to use the GPL. Or else, you can just look at how I wrote it and get only the audio part (as the lib extracts also the video informations) Example of output with the CLI: Filename....................: ********.mp3 Size........................: 6,2 MB (or 6305,8 KB, or 6457150 B) Container...................:  no informations Streams   |   +-Audio stream #0      +-Mimetype..............: audio/mpeg      +-Decoder info      |  |      |  +-Name...............: mad mp3 decoder      |  +-Description........: Uses mad code to decode mp3 streams      |  +-Class..............: Codec/Decoder/Audio      |  +-Author.............: Wim Taymans <<a href="mailto:wim@fluendo.com">wim@fluendo.com</a>>      |      +-Duration..............: 0:04:29.31916666      +-Sample rate...........: 44100      +-Sample count..........: 11864307      +-Channels..............: 2      +-Endianess.............: 0      +-Width.................: 32      +-Depth.................: 32      +-Signed................: yes I hope this helps. Regards, Vincent Torri On Fri, 13 Apr 2007, Mario Torre wrote: > Hello! > > My project for the Google Summer Of Code was accepted as part of the GNU > Project: > <a href="http://code.google.com/soc/gnu/appinfo.html?csaid=FDB6DFFB07FE351C">http://code.google.com/soc/gnu/appinfo.html?csaid=FDB6DFFB07FE351C</a> > > As I said in an earlier mail, my task is to hook GStreamer into GNU > Classpath. > > Now, I've found a problem that is blocking me from a couple days and is > taking me away all my sleep :) > > I need to write a (Java) class that displays this kind of information > about an audio file: > > * Encoding type > * Sample rate > * Sample size in bits > * Channels > * Frame size > * Frame rate > * Endiannes > * Header size > > Of course, I could just add a reader for any given kind of audio file, > but then this is pointless to have a gstreamer hook that can recognize > (almost) any type given the right plugin. > > My problem is that I can't find an example of how to parse a file and > extract this data (I need to do that in C, not Java). The program should > return as soon as all these info are retrieved (if possible). I've see > the Discover class from the python bindings (which seems to be what I'm > looking for), but I hate to admit that I was unable to recreate its > behaviour, though I think I'm on the correct way. What I'm doing is this > (to see what capabilities an element has), I get a typefind element and > attach a signal handler to it, but this seems to be not enough, and all > the output I get is: > > ----- > application/ogg > print_pad > size of caps: 1 > fields in structure: 0 > ----- > > [...] > g_signal_connect (G_OBJECT (typefind), "have-type", >                    G_CALLBACK (have_type_callback), loop); > [...] > > gboolean have_type_callback(GstElement *typefind, >                            guint probability, >                            const GstCaps *caps, >                            gpointer data) > { >  [...] >  GstStructure *st = NULL; >  int size = 0; > >  g_fprintf (stderr, "print_pad\n"); > >  size = gst_caps_get_size (caps); >  g_fprintf (stderr, "size of caps: %d\n", size); > >  for (int j = 0; j < size; j++) { >    st = gst_caps_get_structure (caps, j); >    if (st != NULL) { >      size = gst_structure_n_fields (st); >      g_fprintf (stderr, "fields in structure: %d\n", size); > >      for (int i = 0; i < size; i++) { >        g_fprintf (stderr, "field name: %s\n", >                   gst_structure_nth_field_name(st, i)); >      } >    } >  } > [...] > } > > I'm a bit new to all that, so forgive me if I'm doing some incredibly > stupid mistake :) > > Thanks for all the help, > Mario > -- > Lima Software - <a href="http://www.limasoftware.net/">http://www.limasoftware.net/</a> > GNU Classpath Developer - <a href="http://www.classpath.org/">http://www.classpath.org/</a> > Jabber: <a href="mailto:neugens@jabber.org">neugens@jabber.org</a> - Profile: <a href="http://www.gtalkprofile.com/profile/9661.html">http://www.gtalkprofile.com/profile/9661.html </a> > pgp key: <a href="http://subkeys.pgp.net/">http://subkeys.pgp.net/</a> > PGP Key ID: 80F240CF > Fingerprint: BA39 9666 94EC 8B73 27FA  FC7C 4086 63E3 80F2 40CF > > Please, support open standards: > <a href="http://opendocumentfellowship.org/petition/">http://opendocumentfellowship.org/petition/</a> > <a href="http://www.nosoftwarepatents.com/">http://www.nosoftwarepatents.com/</a> > > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys-and earn cash > <a href="http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV">http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV</a> > _______________________________________________ > gstreamer-devel mailing list > <a href="mailto:gstreamer-devel@lists.sourceforge.net">gstreamer-devel@lists.sourceforge.net</a> > <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel"> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> > > -- > Ce message a été vérifié par MailScanner > pour des virus ou des polluriels et rien de > suspect n'a été trouvé. > Message délivré par le serveur de messagerie de l'Université d'Evry. > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash <a href="http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV"> http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV</a> _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.sourceforge.net"> gstreamer-devel@lists.sourceforge.net</a> <a href="https://lists.sourceforge.net/lists/listinfo/gstreamer-devel">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> </blockquote></div>