I've never used the Sony Authoring system, but I have played briefly with their encoding set-up. I do remember being told that if you use the Sony equipment in conjunction with each other, it was possible to author a seamless layer break as the encoder could be told / would calcualate where the layer break would go doing a feature, and would gradually bring the bitrate down either side of the layerbreak, allowing the DVD player to store more frames in it's buffer as it were. As I said, not having used the authoring system, who knows if this was true or not.

As I say, true Seamless branching via the proprietry authoring setups (I believe there is 1 in the UK!) involves one system doing the encoding and authoring (and multiplexing), because it involves some pretty tricky juggling of frames and bitrates and gop sizes.

DVD-BOY