When I play HDTV with AC3 audio, and decode the AC3, the peak audio level is low.
From watching the "Peak Level" in DSP Studio, it stays around a few percent. I can safely add 11-15 dB without any clipping. This is during the loudest part of commercials (which are louder than the program).
I wouldn't expect this much headroom in the signal, so I'm wondering if we should bake in a +10dB (or whatever) gain? Or if it's attenuating channels to provide LFE headroom, or something else?
Does anyone have the tools to make a sample 5.1 file that plays at 100% on all the channels? It would be interesting to see what the decoded levels looked like.
I haven't compared ffdshow to AC3Filter to LAV, but I should do that too.
Thanks for any insight or sample files.