Return-Path: Message-ID: <20040604215717.30223.qmail@web52309.mail.yahoo.com> Date: Fri, 4 Jun 2004 14:57:17 -0700 (PDT) From: Aarti Kumar Subject: Re: [Bluez-devel] Thoughts about AVDTP support To: Marcel Holtmann , BlueZ Mailing List In-Reply-To: <1085900700.12117.106.camel@pegasus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii List-ID: Hi Marcel, The bluetooth avdtp specification is complex but the if we are dealing with the basic functionality part itself and it reduces a lot of complexities. What makes you think that avdtp is using Multiple l2cap channels between same devices with same PSM - is it beacuse of the siganlling link and data transfer link ? Using AVDTP as kernel module is good idea (much better than using it at user space). I think the connection oriented socket is required for avdtp. Its also mentioned in the specification. I would like to help with coding and testing if it fine with you. I had started with the AVDTP implementation, but it was at the user level only and I have not much experience coding at kernel level. Thats it for now. Aarti. --- Marcel Holtmann wrote: > Hi Folks, > > I think one of the next major goals of BlueZ should > be the support of > the Audio/Video Distribution Transport Protocol > (AVDTP). So I spent some > time in reading the protocol specification. The > specification is very > complex and I think most of the products will only > support the basic > mode with signal and media channel. However it took > me some time to > realize that they are using multiple L2CAP channels > between two devices > with the same PSM. I never thought that this was > possible, but our L2CAP > core already supports such configuration. Now I > asked myself, why HID > and HCRP needed two different PSM values? > > To be capable of handling multiple audio and video > streams nicely, I > think we need to implement AVDTP as a kernel module. > In that case we can > make use of two different interfaces to AVDTP. One > for the A2DP support > that is directly connected to ALSA and the second > should be a simple > socket interface. I am no audio/video streaming > expert, so what socket > type is the best for this case? > > Before I start writing any source code, I would like > to get my hands on > a product that already uses AVDTP. I need to know > what parts of this > protocol are in use and how they handle it. > Searching for an end user > product I found one from Air2U (www.air2u.com.tw). > The german reseller > is Aiptek and they call it BT MusiCool 300 > > > http://www.aiptek.de/index.php?mapid=31&katid1=4&detailid=11 > > I asked them to donate one of these to me, but they > said no. Actually > not a nice company. Searching a little bit more I > found out that Amazon > is selling it for 99 EUR. This is fair price for two > Bluetooth devices > (SNK and SRC), but I decided not to buy them. My > conclusion was that if > I should really start working on AVDTP, someone else > should buy me an > end user device for testing any of my code. However > there is always the > possibility to donate money > (www.bluez.org/sponsors.html) which I can > use to buy unsupported hardware. > > Regards > > Marcel > > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: Oracle 10g > Get certified on the hottest thing ever to hit the > market... Oracle 10g. > Take an Oracle 10g class now, and we'll give you the > exam FREE. > http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click > _______________________________________________ > Bluez-devel mailing list > Bluez-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bluez-devel __________________________________ Do you Yahoo!? Friends. Fun. Try the all-new Yahoo! Messenger. http://messenger.yahoo.com/