Panasonic DMP-BD50 user manual available for download.

[captainrac]

Originally Posted by crackinhedz

If you set to 'Custom' and turn secondary audio to "off", you will get 7.1 PCM.

[Note]
Enjoying 7.1ch LPCM
Connect this unit to your amplifier/receiver using an HDMI cable, and select “Quality” or “Custom” and then set “BD-Video Secondary Audio” to “Off”.



so yes, you can get 7.1 internal decoding.

No. Read it carefully. If you set Custom and BD-Video Secondary Audio to "Off" you will get 7.1 PCM but only if that is the input source. If the input source is DTS-MA 7.1 bitstream, the output will be DTS-MA 7.1 bitstream and the receiver must do the decoding. When the decoders are turned on the player restricts output across the board to 5.1. The manual is very cleverly (and deceptively) written IMO