Re: [Bluez-devel] Multiple Headsets

[Lars Grunewaldt <lgw@dark-reality.de>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Jeff Fern wrote:
| Hello Lars,
|
| I am now running a 2.6.10 kernel and the latest patch from bluez.org.
|
| I have seen the previous threads about multiple headsets which refer
to the
| isoc parameter for the kernel module, however this does not make any sence
| to me.

maybe you should read the bt specs, you might understand than.

In short: for hci_usb, the isochronous transfers (sco) share one
"endpoint" of the hci->usb connection. This connection must have the
correct bandwith so that all data can be send. There are different
settings that reflect this, dig the mailing list archives, I wrote a
table a few days ago.

The default setting is 16 bit, suitable for exactly one headset with 16
bit uncompressed signed int audio, or 2* 8bit (not supported by btsco
unless you hack the snd-bt-sco alsa driver so it tells alsa "we are 8
bit). If you want to use two headsets, you have to select the corrent
isoc endpoint. Check my table for details.

We'll bring this information to the web page asap, too

| Suriyan, in your reply you said you've sucessfully got it working. Is it
| possible for you to send me some details on how you did this?
|
| My knowledge of C / kernel stuff is fairly limited so please go easy on me
| :)

It's more BT knowledge that matters here ;)

best regards,
~  Lars

| -----Original Message-----
| From: bluez-devel-admin@lists.sourceforge.net
| [mailto:bluez-devel-admin@lists.sourceforge.net] On Behalf Of Lars
| Grunewaldt
| Sent: 10 January 2005 11:32
| To: bluez-devel@lists.sourceforge.net
| Subject: Re: [Bluez-devel] Multiple Headsets
|
| first, it would be a good idea to update to the latest available sources
| (that is, 2.6.10 kernel and mh10 patchset).
|
| I think we do support multiple sco connections now, but you must
either use
| 8-bit-audio (by hacking the btsco stuff) or hack the kernel.
|
| The problem in short: the hci_usb driver that handles the bt dongles needs
| to know how many data has to be send. So if using two 16bit channels, it
| needs to switch to the 32bit-mode, not the 16bit mode that is used by
| default.
|
| This switching is not handled automatically by now (or, not handled in any
| way to be precise), and while we are talking about it a lot, I think
nobody
| fixed this by now (this includes me).
|
| Maybe you want to dig the list archives and have a look at discussions
about
| sco...
|
| best regards,
| ~  Lars
|
|
| Jeff Fern wrote:
| | Hello all,
| |
| | I have sucessfully got Bluez and the bt-snd-sco alsa stuff working
| | with my debian 2.6.9 and mh5 patch.
| |
| | What I would like to do is get two headsets working, as two seperate
| | audio devices so I can cat /dev/dsp1 to /dev/dsp2 and pass audio
through.
| |
| | Whenever I currently try and connect two headsets, the second one
| | reports the SCO channel is already in use.
| |
| | I do have two bluetooth USB dongles that can be used (although would
| | like to just use one if possible).
| |
| | I should point out that my background is in Java and not C, so
| | although I have examined the bt-snd-sco and btsco source files, I do
| | not understand them enough to be able to see what is going on.
| |
| | Any help would be much appreciated,
| |
| | Regards,
| |
| | -Jeff Fern
| |
| |
| | -------------------------------------------------------
| | The SF.Net email is sponsored by: Beat the post-holiday blues Get a
| | FREE limited edition SourceForge.net t-shirt from ThinkGeek.
| | It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
| | _______________________________________________
| | Bluez-devel mailing list
| | Bluez-devel@lists.sourceforge.net
| | https://lists.sourceforge.net/lists/listinfo/bluez-devel
| |
|
|
| --
| Lars Grunewaldt
| * software development
| * multimedia design
| skills: C/C++/Java/PHP/(X)HTML/Flash/audio/video
| web: http://www.dark-reality.de
| mail: lgw@dark-reality.de

- -------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE
limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel



- -------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel



- --
Lars Grunewaldt
* software development
* multimedia design
skills: C/C++/Java/PHP/(X)HTML/Flash/audio/video
web: http://www.dark-reality.de
mail: lgw@dark-reality.de
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQFB6tFrQWC6DTWkDAoRAsVUAKCbkWj5cjzLBij67liVIqP19aQtawCfZiAw
DyxS4oFhIqfqwRa0Q/wxJgk=
=jf9+
-----END PGP SIGNATURE-----


-------------------------------------------------------
The SF.Net email is sponsored by: Beat the post-holiday blues
Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek.
It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt
_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel