A2DP ?

Maksim Yevmenkin maksim.yevmenkin at gmail.com
Fri Sep 17 18:16:17 UTC 2010

On Fri, Sep 17, 2010 at 2:18 AM, Iain Hibbert <plunky at rya-online.net> wrote:
> On Wed, 8 Sep 2010, Federico Lorenzi wrote:
>> I seem to recall that getting it to work in userspace wouldn't be "much"
>> effort. Last I heard, the code for SCO sockets was a bit unstable, but
>> worked. You could in theory hook this up to something like gstreamer with
>> its sbc codec built in, or write your own program that encodes and send the
>> audio data.
> The SCO sockets are not required, since A2DP uses RFCOMM to transport data
> that I recall

on later, i believe its l2cap actually :) on former, i agree, the exact quote

The Advanced Audio Distribution Profile (A2DP) defines the protocols
and procedures that realize distribution of audio content of
high-quality in mono or stereo on ACL channels. The term “advanced
audio”, therefore, should be distinguished from “Bluetooth audio”,
which indicates distribution of narrow band voice on SCO channels as
defined in Chapter 12 of Bluetooth Baseband specification.

> I'm not sure how audio management works in FreeBSD, wether just feeding
> the data to /dev/audio is enough or really if you need to make it

i doubt it. audio said to be encoded in SBC (mandatory) with optional
support for MPEG-1,2 Audio, MPEG-2,4 AAC and ATRAC (whatever that is).
so decoding is needed, imo.

> available some other way. I have thought of doing something on NetBSD
> using the pad(4) driver[*] which would enable a daemon to provide a system
> standard audio interface (eg on /dev/audio2) that you can use with your
> favourite music player but have been distracted by other things.

yeah, i would do something like this too. no pad(4)  on freebsd though :(

> I have a pair of A2DP headphones that I can use to listen to music from my
> phone and it is kind of nice but I guess that there needs to be remote
> control interfaces with different music players too, perhaps they have
> them already..?

another exact quote :)

Note also that the A2DP does not include remote control functions.
Devices may support remote control features by implementing both A2DP
and the control profile as depicted, for example, in the usage
scenario of Audio/Video Remote Control Profile.


More information about the freebsd-bluetooth mailing list