Hello m4p,
You cannot do what you want with the factory firmware, not over wireless at least.
In DD-WRT there are two options to achieve what you want, but expect a bumpy ride. People have reported trouble in setting it up, even with your particular model. Not sure if they didn't follow the instructions correctly or if there were problems between the routers.
You'll have to test for yourself. I have a D1 and I never did this setup myself, but I can help you with things you don't understand or to troubleshoot. My answers won't always be timely, though.
With that out of the way, let's get into it. First of all, flashing. You can do both ways, but emergency room is the safer choice I guess. People have reported problems with browsers other than IE though, so use IE 7 or 8.
The latest build for you model is: ftp://dd-wrt.com/others/eko/BrainSlayer-V24-preSP2/2011/02-17-11-r16214/dlink-dir615e1/dir615e1-factory-to-ddwrt-firmware.bin
Immediately after flashing, before doing any configuration or settings, start following the instructions here: http://www.dd-wrt.com/wiki/index.php/Client_Bridged
If that doesn't work out there's also the simple Client mode http://www.dd-wrt.com/wiki/index.php/Client_Mode_Wireless
The difference is that with client mode, devices behind the second D-Link will be on a different subnet. Also, I've heard reports of the LAN ports not working in Client Bridge for some reason. In that case you can try using the WAN port for wired connection to your blu-ray player. Just check the "Assign Wan port to a switch" option if you have it.
But let's tackle problems as we encounter them. So, feel free to start testing. G'luck.