Hi Bob, Thanks for your kind reply. Several more questions related to this. For my project, I want to use MPEG4 simple profile and AMR-WB. About MPEG 4 Simple profile, your answer is clear, either I install gst-ffmpeg, or install gst-plugins-bad 0.10.14.1. For AMRWB, i need to install <a href="http://gstreamer.freedesktop.org/modules/gst-plugins-bad.html">gst-plugins-bad</a> 0.10.13.1. My question is: 1. Which version of gst-plugins-bad version should I choose? It seems XVID and AMRWB are in different gst-plugins-bad versions. 2. I have gstreamer 0.10.12 and gst-plugins installed (base 0.10.12,good 0.10.5, bad 0.10.4, ugly 0.10.5). However, when I try to play video or audio (gst-launch playbin uri=file:///home/Music/test.avi ), or when I use gst-inspect alsasink, I always got error message that says I do not have plugin installed. If I just type gst-inspect, I get nothing. I checked /usr/bin, /usr/lib folders, the gst stuff are there. PATH seems to be correct. What is the problem? Is it because I use the wrong version of the plugins? Thanks for your kind help! Stella <div class="gmail_quote">On Fri, Oct 16, 2009 at 10:53 AM, Robert Swain <<a href="mailto:robert.swain@gmail.com">robert.swain@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hello, 2009/10/13 Xing Fan <<a href="mailto:xing.fan0302@googlemail.com">xing.fan0302@googlemail.com</a>>: <div class="im">> I want to use mpeg 4 simple profile codecs. I wonder which gstreamer > plugin should I install? I checked all the plugins, only find mpeg 4 parse > in plugin bad. Where are the codecs. Thanks for your kind help! </div>For decoding: ffdec_mpeg4 (i.e. install gst-ffmpeg) or xviddec (gst-plugins-bad) For encoding: xvidenc (i.e. gst-plugins-bad) or ffenc_mpeg4 (gst-ffmpeg) I'd recommend FFmpeg for decoding and XviD for encoding. You will need to specify settings appropriately to be compliant with the MPEG-4 Part 2 Simple Profile restrictions though. Regards, Rob ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! <a href="http://p.sf.net/sfu/devconference" target="_blank">http://p.sf.net/sfu/devconference</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" target="_blank">https://lists.sourceforge.net/lists/listinfo/gstreamer-devel</a> </blockquote></div>