I originally started looking into this as part of my Nexus 7 car project. Rebooting just to get USB audio working conflicted with my goal of being able to "dock and forget". It took a bit of experimenting and debugging but it's finally working
This program should enable USB audio support on your Nexus 7 - that means you are able to plug and unplug a USB sound card without having to reboot in order for it to work. Other devices should also work but I have not been able to fully test.
It works by downloading your devices services.jar which is then extracted and de-odexed if required. The necessary classes are then patched and a new services.jar is packaged up, re-odexed, re-signed and finally re-uploaded to your device. The previous method replaced the entire services.jar which turned out to be a really bad idea!
As always please let me know of any issues you stumble upon. The patching software was written quickly so there will most likely be bugs!
- Obtain a full backup of your device. This patch is experimental.
- Ensure your device is ADB enabled, rooted and has busybox installed.
- Make sure your PC has Java and .NET 4 installed.
- Download usb-audio-patcher below and extract to a folder.
- Run usb-audio-patcher.exe, the software will guide you through the rest of the process.
- Flash a kernel with USB audio support. Nexus 7 Wifi kernels can be found below although any kernel with USB audio support will work.
[N7 CM10 / Stock 4.1.2] cm-10-n7-wifi-usb-audio-kernel.zip
[N7 CM10.1 / Stock 4.2.1] cm-10.1-n7-wifi-usb-audio-kernel.zip
[Timurs N7 Kernel] http://rootzwiki.com...ment-usb-audio/
[Volume Control] n7-volume-control-patch.zip - Allow media volume control when USB audio device is connected.