Specifications

Windows Embedded Automotive 7 Deep Dive: Phone Core and Media Core 47
HKEY_LOCAL_MACHINE\Software\Microsoft\Automotive\BTAV
All keys and values under the BTAV key are optional. The BTAV service will use default values if a value is missing or
outside of the appropriate range. This key includes one subkey for each supported codec.
Name
Type
Description
WaveOutDevice
DWORD
The device Line Out ID for the wave driver that is assigned to A2DP when
the wave driver has multiple line outs. The default value is WAVE_MAPPER.
OutputWaveBufferSize
DWORD
The size of each output buffer in the output buffer set. The value must be
greater than 1,024. The default value is 1,024*5.
InputBufferTime
DWORD
The amount of time buffered for the input. The value must be greater than
100. The default value is 200.
OutputBufferTime
DWORD
The amount of time buffered for the output. The value must be greater than
100. The default value is 400.
DataTimeoutPercentage
DWORD
Indicates whether data is still being sent. The wait timeout is calculated by
OutputBufferTime * DataTimeoutPercentage / 100. If no data is received for
this amount of time, then it is presumed that the streaming has stopped.
The default value is 50.
PrintBPSAverage
DWORD
The time frequency, in milliseconds, that is taken to print out the average
bits/seconds. For example, if this registry setting is set to 30,000, then the
service will print out a message every 30 seconds. The minimum value is
1,000 and maximum value is INFINITE. A default value is not set.
TimeoutAVRCPConnection
DWORD
The AVRCP timeout for connection setup. The default value is 5,000.
TimeoutCheckPairing
DWORD
The timeout when checking for whether or not the device is paired. The
default value is 1,000.
NumItemsPerQuery
DWORD
The number for subrequests that constitute a query. With AVRCP 1.4, a
device can be queried using a file system folder model. For example, a folder
on the device file system named “Music” could contain all of a user’s music
files, which could number into the thousands. To handle the query for all of
the files in this folder, the query is automatically broken up into
subrequests, where the number of items per actual query is defined by this
registry setting. The minimum is 1 and the maximum is 1,000. The default
value is 5.
HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT \BTAV\SBC
The Sub-Band Coding (SBC) codec is the only required codec for the A2DP. This registry key is used to store default
information for the SBC codec.
Name
Type
Description
CLSID_SBCDMOMediaObject
GUID
The universally unique identifier (UUID) to find the DirectX Media Object
(DMO) for the decoding process. The default value is {33FBF37D-60C9-
4fb6-9638-081AF124036D}.