<div class="gmail_quote">2011/9/29 Rossana Guerra <<a href="mailto:guerra.rossana@gmail.com">guerra.rossana@gmail.com</a>> <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> Hi, I use gnlfilesource, gnloperation, alpha channels, videomixer,fmpegcolorspace I can play the videos correctly but I can not hear the sound. If I play the video with any other application it works fine (image and sound). What did I miss to set? Thanks Rossana _______________________________________________ gstreamer-devel mailing list <a href="mailto:gstreamer-devel@lists.freedesktop.org">gstreamer-devel@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel" target="_blank">http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel</a> </blockquote></div> AFAIK, you need two separate gnlsource objects, one for video and one for audio.