CHT9000 A2DP音質改善

從這裡來的：

http://forum.xda-developers.com/viewtopic.php?t=54621

修改前請備份reg.，風險自負。修改後soft reset。個人感覺，還真改善不少！

HKLM\Drivers\BuiltIn\BtA2dpSnd
增加 Priority256 dword 60

HKLM\SOFTWARE\Microsoft\Bluetooth\AudioGateway\Capability
修改Dword 37 --> 69

HKLM\SOFTWARE\Microsoft\Bluetooth\A2DP\Settings
增加 BitPool dword 51
增加 SampleRate dword 48000

2006-07-05 21:42 #1

文章關鍵字

CHT9000 A2DP 音質改善

KSHuang4636

0分

2樓

KSHuang4636

個人積分：0分

文章編號：1401564

比較有影響的應該是 BitPool

這邊列一些設定功參考
The registry settings for the Advanced Audio Distribution Profile (A2DP) are located under the KEY_LOCAL_MACHINE\Software\Microsoft\Bluetooth\A2DP\Settings registry key.

The following table shows the named values for the A2DP\Settings key.

Value : type	Description
BitPool: REG_DWORD	Configures the SBC bitpool settings. By default, A2DP uses a bitpool of 48. A lower bitpool value improves system performance. Increasing bitpool to a higher value causes an overhead on Bluetooth and system resources. For more information about bitpool settings, see the SBC specification at the Official Bluetooth Wireless Info Web site. Microsoft suggests the following bitpool values for optimal buffer sizes. 30 - Low audio quality 40 - Medium audio quality 48 - High audio quality 58 - Excellent audio quality
MaxSupportedBitPool: REG_DWORD	The maximum reported bit pool value, which can be negotiated with the peer device. Default value is 80.
MinSupportedBitPool: REG_DWORD	The minimum reported bit pool value, which can be negotiated with the peer device. Default value is 14.
SampleRate: REG_DWORD	SBC sample rate to use. Default value is 44.1 KHz.

HKLM\SOFTWARE\Microsoft\Bluetooth\AudioGateway\Capability 的 bitmask
要先把設定轉成 hexdecimal 不過 AG 跟 A2DP 比較沒關系

#define AG_CAP_3WAY_CALL 0x01
#define AG_CAP_EC_NR 0x02
#define AG_CAP_VOICE_RECOG 0x04
#define AG_CAP_INBAND_RING 0x08
#define AG_CAP_VOICE_TAG 0x10
#define AG_CAP_REJECT_CALL 0x20

另外增加 output priority 可能不是改 HKLM\Drivers\BuiltIn\BtA2dpSnd\Priority256
因為也沒有看過 source code 但觀察起來可能是
HKLM\Drivers\BuiltIn\BtA2dpSnd\PriorityRenderOutput256
一樣是 DWORd value

supermuscle

0分

3樓

supermuscle

個人積分：0分

文章編號：1401974

very good.....

818pro可以用嗎??

Vincent Huang

6分

樓主

Vincent Huang

個人積分：6分

文章編號：1402042

supermuscle wrote:
very good....(恕刪)

不太確定818pro是不是MS BT stack......所以......

我把Priority256改成PriorityRenderOutput256，原本會打嗝的耳機似乎改善了一些...謝謝KSHuang4636兄

另，請問KSHuang4636兄，能不能讓小弟知道您引用的資料的來源？我在找類似的資料，但一直找不到，謝謝！