I assume you build gstreamer with mingw not with visual studio. Ideally the concept of release build and debug build is applicable to visual studio compiler only. If you have built Qtgstreamer with visual studio and gstreamer with mingw(This is what i have used), only the following libraries should differ for debug and release build. QtGlib QtGstreamer QtGstreamerUi QtGstreamerUtils QtGstreamerQML This is what I have followed. gstreamer -> mingw32 QtGstreamer-> VisualStudio 2010 In QtGstreamer release build, I was having some problem with the build key in QtGstreamerQML CMAKE could not set the Build key for the QtGstreamerQML.dll right. I had to rebuild the QtGstreamerQML with the QT Creator to set the Build key right. Regards Dinesh P <div class="gmail_extra"> <div class="gmail_quote">On Thu, Dec 13, 2012 at 7:31 PM, Dinesh Kumar <<a href="mailto:dineshkpadmanaban@gmail.com" target="_blank">dineshkpadmanaban@gmail.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class="gmail_extra">Can you give me more details? Are you getting any message like "Build key does not match " ? Regards Dinesh P <div class="gmail_quote">On Thu, Dec 13, 2012 at 7:13 PM, Chris Boucher <<a href="mailto:chris@thebouchers.com" target="_blank">chris@thebouchers.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> directory called qtgstreamer):</blockquote></div> </div> </blockquote></div> </div>