The standard way of getting this stack to work is to pass through the digital audio signal as-is from the source media to the amplifier. This means that the system cannot mix in other sounds, like system notifications, to the audio output stream without scrambling the original proprietary DTS/AC3 digital encoding of the audio stream. In short, you need an exclusive access to the audio stream for the application you are using. Normal Linux sound system mixers, such as Pulse and GStreamer are poison,
I haven't been able to get digital surround sound working with these, and I am not convinced that there is a way. However, you don't need to uninstall your convenient sound system stack, just make sure that your video player application skips the stack and goes directly to the sound card, for example by using ALSA.