I have a rooted Android Device running Android 2.3 Gingerbread and a PC(with Bluetooth dongle) running windows 7.
My mobile has Bluetooth with A2DP support. I want to output the audio(not just music) of my PC to my Android Device over Bluetooth. i.e. I want my android device to work as an Audio Output Device(like headset) for my PC.
How to do it?
Dev0 and hello are correct - no you cannot connect using your Android device as a A2DP sink given the standard Android bluetooth stack. Stack Overflow user Dennis Mathews explains why:
You may not be able to [create an A2DP connection] manually between 2 phones also because to stream one device needs to be A2DP sink and other A2DP source; phones are typically only source devices (source of the stream that can stream to sink devices), sinks are headsets or Bluetooth speakers.
He and the OP briefly discuss options for replacing the stack but their conversation dies without a concrete answer...as it seems several other similar questions around the web do. XDA user zelendel, in general, isn't very hopeful about the matter - when asked if it was possible to replace the bluetooth stack he responded:
Simple answer is no. You can try a CM based rom that gives you those options but the stacks can't be swapped due to driver problems. It is a give and take. The Default has better strength and range but is missing a few unneeded option (PO), while CM uses Bluz stack which gives you the option but you lose some BT signal strength and range.
Sorry, it seems to me you're out of luck.
It is not possible via Bluetooth on Android, only from phone to PC, not from PC to phone.
But here are some solutions you may be able to use:
The easiest way to do it is using SoundWire.
Another way to do it is to use Splashtop remote, which uses your WiFi or 3G to remote control your PC and sends high-quality audio and video to your phone, but if you are on 3G it can use a lot of data, so it can get expensive.
The next thing is to use the AirBubble app and Airfoil to stream audio from PC to Android device.
I found this developer's technique https://stackoverflow.com/questions/15557933/receive-audio-via-bluetooth-in-android to accomplish this, although he says it can't be done with an app. I am not a developer, but if this works maybe someone can find a workaround that could allow an app to accomplish the required changes at least on a rooted phone.
I think it is pretty clear why this feature is not available, it is just another way of stopping us copying copyrighted material, although there are still plenty of ways to do it which are actually more convenient than streaming would be.
There is also effort to create Android audio receptor for VBAN protocol from VB-Audio company. Once it is out it should be best thing you can get hands on latency-wise.
2017-03: The VBAN receptor for Android has been released. However it is utilizing UDP, not Bluetooth.
SoundIt does just that, but over wifi.
It lets you stream the sound output of your PC to any web browser so you can stream to any phone or even another PC. You can stream to multiple devices at the same time and control each device's volume output remotely.
You can attach a Bluetooth receiver device to your phone, available on Amazon thus your phone will receive Bluetooth audio.
Now, if you want to attach both headphones and this device, attach a splitter to the audio jack. This is my suggestion.
On win10/11, enable bluetooth. In Network & internet settings:
