[alsa-devel] about UCM on bluetooth headset
Hi Liam,
In alsa-libs:include/use-case.h, there are below lines:
* a conversation etc. The device describes the physical audio capture and playback * hardware i.e. headphones, phone handset, bluetooth headset, etc.
I'm not quite clear about how to set a use case for bluetooth headset. According to my understanding, bluetooth doesn't fall into the category of ALSA, therefore there's no such direct devices for it.
Could you shed some lights on this? What's the best practises to use UCM with bluetooth?
On 22/08/11 07:19, Lu Guanqun wrote:
Hi Liam,
In alsa-libs:include/use-case.h, there are below lines:
- a conversation etc. The device describes the physical audio capture and playback
- hardware i.e. headphones, phone handset, bluetooth headset, etc.
I'm not quite clear about how to set a use case for bluetooth headset. According to my understanding, bluetooth doesn't fall into the category of ALSA, therefore there's no such direct devices for it.
Could you shed some lights on this? What's the best practises to use UCM with bluetooth?
This is intended for systems where the BT audio is integrated in some way with the other audio ICs. It's intended to configure the other audio devices to allow use cases involving BT in such systems.
Liam
On Mon, Aug 22, 2011 at 06:46:02PM +0800, Liam Girdwood wrote:
On 22/08/11 07:19, Lu Guanqun wrote:
Hi Liam,
In alsa-libs:include/use-case.h, there are below lines:
- a conversation etc. The device describes the physical audio capture and playback
- hardware i.e. headphones, phone handset, bluetooth headset, etc.
I'm not quite clear about how to set a use case for bluetooth headset. According to my understanding, bluetooth doesn't fall into the category of ALSA, therefore there's no such direct devices for it.
Could you shed some lights on this? What's the best practises to use UCM with bluetooth?
This is intended for systems where the BT audio is integrated in some way with the other audio ICs. It's intended to configure the other audio devices to allow use cases involving BT in such systems.
Hi Liam,
Thanks, I got your point. For example, where BT HSP is implemented over ALSA PCM, it's most probably exposed as an ALSA device, then we can configure it.
On Mon, Aug 22, 2011 at 11:46:02AM +0100, Liam Girdwood wrote:
On 22/08/11 07:19, Lu Guanqun wrote:
- a conversation etc. The device describes the physical audio capture and playback
- hardware i.e. headphones, phone handset, bluetooth headset, etc.
Could you shed some lights on this? What's the best practises to use UCM with bluetooth?
This is intended for systems where the BT audio is integrated in some way with the other audio ICs. It's intended to configure the other audio devices to allow use cases involving BT in such systems.
Specifically it's for BT SCO (in call 8kHz headset modes). In call audio generally doesn't go through the CPU, the BT device has a path to the baseband via some other route which is typically similar to or part of the connection the CODEC has which bypasses the CPU entirely allowing the CPU to be suspended.
[Liam, your mailer still isn't word wrapping within paragraphs.]
participants (3)
-
Liam Girdwood -
Lu Guanqun -
Mark Brown