Re: [Bluez-devel] SCO Question

[Mikael Bengtsson <micke_b.b@hotmail.com>]

[-- Attachment #1.1: Type: text/plain, Size: 2717 bytes --]


I have now redirected SCO to ALSA. I setup ALSA as a player, that is, sound shall be played on the soundcard. The hardest part in ALSA was to set the correct number of frames and number of periods, but with the help of tutorials on the web it worked out.
 
Now I have set up ALSA to play 32 frames, 2 periods, mono, 8 kHz, S16_LE (signed 16 bits little endian on my Intel XScale PXA255). This means 64 bytes of data (one frame = one sample is 2 bytes when mono). This corresponds to sound from SCO.
 
Unfortunately, on my system SCO delivers only 60 bytes of data per read operation, HV3 delivers 30 bytes in one package, which doesn't add up with the soundcard. The soundcard (AC97-based) wants 16, 32, 64 bytes and so on. Therefore the sound isn't of good quality. On other soundcards it may be possible to set a frame size which corresponds exactly to SCO.
 
I think I will have to do some buffering from SCO before allowing ALSA to play sound. 
 
-Mikael
> From: marcel@holtmann.org> To: bluez-devel@lists.sourceforge.net> Date: Fri, 24 Aug 2007 14:06:53 +0200> Subject: Re: [Bluez-devel] SCO Question> > Hi Robert,> > > How would I go about redirecting incoming SCO data to an alsa device, > > and transmit incoming audio data out as SCO?> > > > I have read the following pages,> > http://wiki.bluez.org/wiki/Audio> > http://wiki.bluez.org/wiki/HOWTO/AudioDevices> > > > but everything described seems to do too much. I would prefer to > > handle the RFCOMM channel, and SDP registration elsewhere. > > Presently, I just want to determine how to redirect the SCO traffic.> > actually you can't really do SCO without a profile. In theory you can,> but that is to compatible with out devices. Since this kind of> application doesn't really make sense for most people we didn't focus on> it and so nothing like that is available. However hstest.c and other SCO> demos can be used to quickly write something like that. The hardest part> is to get the ALSA thing right. Again, you have to write that by> yourself since we have no need for this right now.> > Regards> > Marcel> > > > -------------------------------------------------------------------------> This SF.net email is sponsored by: Splunk Inc.> Still grepping through log files to find problems? Stop.> Now Search log events and configuration files using AJAX and a browser.> Download your FREE copy of Splunk now >> http://get.splunk.com/> _______________________________________________> Bluez-devel mailing list> Bluez-devel@lists.sourceforge.net> https://lists.sourceforge.net/lists/listinfo/bluez-devel
_________________________________________________________________
Nu kan du får Messenger i mobilen, läs mer!
http://www.mobil.msn.se/

[-- Attachment #1.2: Type: text/html, Size: 3322 bytes --]

[-- Attachment #2: Type: text/plain, Size: 315 bytes --]

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >>  http://get.splunk.com/

[-- Attachment #3: Type: text/plain, Size: 164 bytes --]

_______________________________________________
Bluez-devel mailing list
Bluez-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/bluez-devel