ReactOS Audio Service (audiosrv.exe)
====================================

This is intended to operate in a similar manner to how the Windows Audio
Service does.

NOTE: The service filename is audiosrv.dll on Windows XP. This shouldn't
have any impact on functionality.

AudioSrv on Windows creates a mapped file at:
Global\mmGlobalPnpInfo

The ReactOS audio device list lives at:
Global\AudioDeviceList

This file appears to contain a list of devices that WinMM accesses and
subsequently passes to wdmaud.drv

It is not necessary to duplicate the exact structure of this mapped 
file, since it appears to only be used internally by Windows components.

The ROS Audio Service (RosAudioSrv) is intended to be able to run 
alongside the Windows Audio Service on XP/Vista, so it should be 
possible to test in a "known working environment" ;)

It will create a mutex, to:
1) Allow synchronization when accessing the device list
2) Provide a simple method of identifying if RosAudioSrv is running

(It might be worth using an event to notify WinMM when things are 
happening?)

The intention is to make RosAudioSrv receive PnP notifications for 
relevant audio devices, and also let AudioSrv in Windows do this. Then 
it should be possible to create a small application that imitates 
WinMM's actions :)


Current Status
==============

AudioSrv registers for device notifications and obtains a list of the
current audio devices in the system (devices registered against the
KSCATEGORY_AUDIO interface).

ReactOS does not currently have RegisterDeviceNotification implemented,
so for the moment this service considers the failure of this API call
to be non-fatal and will proceed without device event notification. This
behaviour will be amended in a future revision (ie once this API call
is implemented!)


Testing the Service
===================

The service can be installed on Windows XP (possibly also Vista) like so:
sc create RosAudioSrv <path to audiosrv.exe>
net start RosAudioSrv

...and can be removed like so:
net stop RosAudioSrv
sc delete RosAudioSrv

You can view a list of the currently available devices (device list is
identical to the one offered by Windows' own AudioSrv) by running
my READER.EXE test utility, available in the following package:

http://stuff.silverblade.co.uk/reactos/sharedlist.tar.gz

That's all for now, folks ;)


Andrew Greenwood
September 2007