First i note that the edition from Feb 27, 2015 seems to be correctER than the current one, since it says "last two bytes of the SAD" (i.e. SAD2, SAD3) whereas next edition says "<number of channels>:<SAD1>:<SAD2>:<PassThru>" but that's very unlikely since SAD1 is the format and number of channels - which we already have decoded as the AA key "DD+" and <number of channels>=8.
This info seems promicing, has somebody decoded it successfully yet?
So trying to decode the SADness: Roku3's reports AC3 (aka DD) as a pass-through with 6 (5+1) channels. 127 seems to be a SAD2 and says "i support 32, 44, 48, 88, 96, 176, 192 kHz (what do i care, i am a passthrough!)". So far so good.
RokuTV reports AC3 and DD+ with 7 channels, where AC3 can play 32, 44, 48, 88, 96 kHz and DD+ can only do 44 and 48 kHz. Seems plausible.
But WTH is 640 (0b1010000000)?! What kind of super-sized byte is that? Not any of the bytes i have met - mine all maxed out at 8bit, i.e. 255 (0b11111111)