[Xperia Play General] Trooper_Max:
It's also worth noting that there are two different "USB to HDMI" potentialities.

The common one supported by some other phones is the "Mobile High-definition Link". You can read about it on Wikipedia, but I actually found this article on a nokia blog a little more enlightening on the specifics:

http://mynokiablog.com/2011/02/27/mobile-high-definition-link-hdmi-and-usb-rolled-into-one/

So then all you need is their new cable, which connects to the micro-USB-like port on the phone and outputs to HDMI.

Notice I said micro-USB-like port - that's the problem with the Xperia Play - the hardware they put in is probably just a standard micro-USB port, not one of these new special micro-USB-like ports that supports outputting to HDMI.

What this is saying is that the special devices which can use the MHL technology are able to automatically detect whether it will be a regular USB data connection or a MHL audio/video connection. This is because the MHL a/v connection provides more power, so when the controller on the phone that has the micro-usb-like connection detects that it is getting more power than a regular usb connection, it knows it is an MHL connection and can act accordingly. Likewise, when it receives the standard juice of a usb connection, it knows to act like a usb device.

And as I understand it, that is what the SE guy above was trying to say - that the hardware in the Xperia Play does not support this additional functionality - the controller that handles the micro usb connection just does not have the functionality to support what I just described above. This is hardware-level stuff that cannot be added on via software. So short of a hardware mod, this solution is impossible.

The good news is that the other type of "USB to HDMI" solution that I was talking about above is different. It is nothing new on the USB side, it is just a standard USB data connection. From there, it goes through a special adapter and the adapter then outputs HDMI. (Notice in the MHL solution above, there was no adapter on the wire - the smarts to provide the additional functionality were in the device/phone) So doing it this way, the phone must act as a USB host and it is communicating with a USB device (the adapter). Over this standard USB data connection, they communicate using a protocol developed by DisplayLink so that the phone can tell the device what to display (so yeah, special drivers are required for this - but those already exist, at least for Linux and someone got it working on the Nexus One). The adapter receives the graphics via the protocol and outputs to HDMI. This solution may be possible (I don't see any technical hurdles as of yet). It will put some additonal strain on the system to have to constantly stream the video out over the usb, but hopefully this will not be too bad - the Xperia Play should be able to do it better than the Nexus One anyway. I don't know if any of these solutions also support audio over the USB at the same time to be combined into the HDMI, but you can always just use a line out from the headphone jack, but that starts to get to the point where you have a lot of wires and adapters.

So I do think a wireless streaming solution sounds very appealing. The first step would probably be to find a small/efficient open-source media server/streamer that you can run on Linux to stream media to your TV or PS3 or whatever receiving device you will use (any suggestions here? I don't really have experience doing this). Or if there are already Android applications that can do this? Then it will just be a trick of streaming the phone's display instead of a media file. Seems like somebody on some phone will have already come up with a solution for streaming media...

~Troop