After spending hours trying to get this to work whilst keeping 5.1 audio i managed to find a way of doing it quickly so thought i would share; 1st off, download these; -CCCP http://cccp-project.net/ -WMNicEnc.zip v1.02 Beta http://nic.dnsalias.com/WMNicEnc/WMNicEnc.zip -Windows Media Encoder 9 http://www.microsoft.com/windows/windowsmedia/forpros/encoder/default.mspx -AviSynth 2.5.7 http://www.freewr.com/freeware.php?download=avisynth&lid=4002 -Media Info http://mediainfo.sourceforge.net/en/Download Before you carry on, uninstall all previous codecs/packs that you have installed. 1. Extract and install the downloaded files 2. Once installed go to the settings of the CCCP (Start>Programs>Combined Community Codec Pack>Settings) and change the FFDShow Audio Settings to No Mixing and untick MP3 from the Audio Decoders. 3. Place your target movie file directly on your hard disk not in any folders then create .avs Avisynth script in notepad and add the following line DirectShowSource("c:\Name Of Your File Here") eg DirectShowSource("c:\TMNTTrailer.mkv") Also enable viewing of file extentions. 4. Load up WMNicEnc and click on advanced options. Select Fastest on the Mininum/Maximum Complexity tab then click ok. 5. (audio) Load up WMNicEnc and untick "Use Video". Select Windows Media Audio 10 Professional and 384kbps, 48kHz, 5.1 channel 24 bit CBR. Add your avs scripe and make sure the output is .wma. Finally tick Use MultiPass Encoder and click start. 6. (video) Again Load up WMNicEnc and untick "use Audio" and tick "Use Video". Select Windows Media Video 9 Advanced Profile, set bitrate to *5000000, quality to 100, use Mediainfo (downloaded earlyer) to find out the FPS and add the amount to the box. Tick USe input size for the Resolution. On the VBR options click "constrained" and tick the max bitrate and add the amount 10000000. Make sure your output is .wmv 7. When finished you will have two seperate files, Now you need to mux them back together. So open up windows media stream editor (start>programs>windows media>utilities>stream editor), Now you need to load your video and audio files. click add source and load your video and audio files what you need to do now is open up each branch till you see 384 kbps box and tick it for audio then same with your mbps video file then press add (see reference pics). Now they will appear in the setup output audiences bar branching of a single file now click create file it will now appear in the bottom bar finally click start it will create the file and save it in the directory you chose. 8. Thats it once finished you will have re-muxed both audio and video and will have a xbox360 ready file with great picture quality and 5.1 sound! *The above is for 720p files, if you want to do the same with 1080p files just change the bitrate too 8000000 and the max bitrate to 15000000 and the FPS accordingly.