5.1 Dts HD- Master/Dolby TrueHD? Onkyo TX-SR507?

I am interested in purchasing a new receiver for my home theater. I am really looking at the tx-sr507. It has onboard Dolby Truehd and DtsMaster. My inquiry is this receiver is only 5.1. If I were to watch a blu-ray with a dts master audio track that was 7.1 mixed. Would I still get the DTS Master or Dolby true track through the receiver? I understand it wouldn't be discrete but would I still ge tthat uncompressed signal via hdmi on the 5.1 setup? Thanks in advance