Hi, I am downmixing 5.1 into stereo, using the LoRo option as I want to create an 5.1 ac3 stream where the matadata flags will force the stereo downmix level of the surround and centre channels to a specific value. My problem occurs because I cannot (not through lack of trying!) find any software that might be able to do this, or . I was wondering if there any programs that would be able to change metadata values within a bit stream or must the stream be re-encoded from scratch to do this. And if which programs might give control over these flags when encoding or changing the metadata. Any help would be greatly appreciated! P.K.