Hi all, I've done a bit of research into mencoder options specifically in an attempt to enable 5.1 surround sound when encoding H264/AAC (for my PS3). Here's what I have so far - it's based on the standard PS3 16:9 profile: Code: [PS3 16:9 (AVC/H264/AAC 5.1)] AllowNativeTVResolution=1 Manufacturer=Sony Playstation 3 ScreenRatio=16:9 Res1=320x240 Res2=640x480 ResAna1=320x180 ResAna2=640x360 ARate=48000 ABRate=384 Format=avi moac=lavc movc=x264 mopts=-channels 6 -lavcopts acodec=libfaac:abitrate=%abrate% -x264encopts bitrate=%vbrate%:level_idc=31:bframes=3:frameref=2:nopsnr:nossim%PASS% FileType=mp4 Quality=15 useMencoder=1 SubTitle=1 MaxVBitrate=2500 AllowChapterFiles=0 MVolume=10 Remux=2642MP4 QualityFactor=130 Results: Mostly working. The resultant mp4 file plays on the PS3 with AAC 5.1 surround sound. Picture is great, sound is great. The only problem is that the channels assignments are not correct. ie: centre audio comes out of right speaker etc. Aparently AC3 channels do not map directly onto AAC channels. I've seen references on the web to the use of the -af switch to reasign the channels. The option looks like this: -af channels=0:1:1:2:2:3:3:4:4:0:5:5 I've tried various ways of adding this into the profile without success. Basically I get a mencoder error if I add the -af switch into the mopts. Any ideas or thoughts for a way forward?