Mobility Site - View Single Post - Widcomm for Axim x50v and x51v. State of the development

mikelspikel · 09-19-06, 03:57 AM

I've found some new registry keys that can be used to tweak the encoding process of the A2DP profile. They can be used to change the bitrate used and the audio quality. And maybe some tweaking can avoid skipping problems...

The keys are:

Under [HKLM\Software\Widcomm\Plugin\AV]
- Blocks (DWORD)
- SubBands (DWORD)
- LineSpeed (DWORD)

In the tests I've done, it seems necessary to set Blocks=16 and SubBands=8 to achieve decent audio quality.

The most interesting parameter is LineSpeed, which seems to be something related to the bitrate (in kbps) the encoder uses to transmit the audio to the headphones. With my device and i.Tech S38, it seems to default to 230. With this default setting, the headphones sound quite well but the quality drop is noticeable (compared to the quality got by listening with wired headphones). I've tried two new values (256 and 320) and the gain is important. With 320, I can't find any difference between wired and BT headphones.

I believe this can be interesting if you find the audio quality got by BT is not perfect. With 320, at least in my case, it is. Moreover, maybe adjusting this parameter to some different values (128, 256 or 320 for example) can be used to avoid skipping? Someone could try (nakedracer?). By the way, no skipping at all with i.Tech Clip S38.

09-19-06, 03:57 AM	#733 (permalink)
mikelspikel Aximsite Major League Join Date: Dec 2005 Location: Bilbao Posts: 311 Thanked 30 Times in 5 Posts	Tweaking A2DP encoder I've found some new registry keys that can be used to tweak the encoding process of the A2DP profile. They can be used to change the bitrate used and the audio quality. And maybe some tweaking can avoid skipping problems... The keys are: Under [HKLM\Software\Widcomm\Plugin\AV] - Blocks (DWORD) - SubBands (DWORD) - LineSpeed (DWORD) In the tests I've done, it seems necessary to set Blocks=16 and SubBands=8 to achieve decent audio quality. The most interesting parameter is LineSpeed, which seems to be something related to the bitrate (in kbps) the encoder uses to transmit the audio to the headphones. With my device and i.Tech S38, it seems to default to 230. With this default setting, the headphones sound quite well but the quality drop is noticeable (compared to the quality got by listening with wired headphones). I've tried two new values (256 and 320) and the gain is important. With 320, I can't find any difference between wired and BT headphones. I believe this can be interesting if you find the audio quality got by BT is not perfect. With 320, at least in my case, it is. Moreover, maybe adjusting this parameter to some different values (128, 256 or 320 for example) can be used to avoid skipping? Someone could try (nakedracer?). By the way, no skipping at all with i.Tech Clip S38. __________________ Enhance your Axim's Bluetooth! Check the state of Widcomm Project To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. . *Free WiFi and BT switch utility for X50 and X51.* Have it a look To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. ! Does your Axim lose the date/time when you change the battery? To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. !