Re: [maemo-developers] Bluetooth headset - not really working?
Ralph Is there a bandwidth problem, or just people being silly with the design? There is a bandwidth problem. High-quality audio is compressed on the fly before transmission. We will probably be able to build in the delay to the video player so it slips the video stream a bit. gstreamer may even have a way to specify in the codec plugin how much latency it introduces. Some of these problems could be fixed if a new audio spec was written that required the extended data rate of bluetooth 2.0 and left out compression. The a2dp spec says nothing about duplex high-quality audio, but there's no reason a headset couldn't try to connect back to the source node on an independent connection when it starts receiving audio. That's basically how the AVRCP connection works. Brad ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
BTW, did anyone notice the following lines in the dmesg output on the 770 in the 51-13 firmware? [4.037261] Bluetooth: L2CAP ver 2.7 [4.041015] Bluetooth: L2CAP socket layer initialized [4.046356] Bluetooth: SCO (Voice Link) ver 0.4 [4.051147] Bluetooth: SCO socket layer initialized [4.056365] Bluetooth: RFCOMM ver 1.5 [4.060272] Bluetooth: RFCOMM socket layer initialized [4.065704] Bluetooth: RFCOMM TTY layer initialized [4.070861] Bluetooth: BNEP (Ethernet Emulation) ver 1.2 [4.076477] Bluetooth: HIDP (Human Interface Emulation) ver 1.1 It mentions SCO. I'm not sure if that means anything or if this was present in the older versions of the firmware, I just thought it was interesting. Also, a few lines above the Bluetooth stuff, you can find: [3.814697] Advanced Linux Sound Architecture Driver Version 1.0.9rc2 (Thu Mar 24 10:33:39 2005 UTC). [3.828033] usbcore: registered new driver snd-usb-audio [3.833709] ALSA device list: [3.836822] #0: Dummy 1 USB Audio? Anyway, I sort of get the feeling that Nokia is keeping so quiet about this mostly because this is something they want to release in the 2006 firmware and they most probably don't want anyone stealing their thunder and releasing a fully-working VoIP package for the 770 before that. With Asterisk and chan_bluetooth ported to the device, the 770 could become the ultimate VoIP phone. Any clues yet from Nokia? :). Razvan -- Razvan Dragomirescu Chief Technology Officer Cayenne Graphics SRL On 1/10/06, Johannes Eickhold [EMAIL PROTECTED] wrote: On Tue, 2005-12-20 at 10:16 -0700, Brad Midgley wrote: I'm overseeing the bluetooth audio on linux project... Linux only supports SCO transfers for CSR chips. To use the current btsco stuff, Nokia is going to have to contribute a SCO driver to the kernel for whatever bluetooth chip they put in the 770. I found some further info at: http://thread.gmane.org/gmane.linux.bluez.devel/6713 Can anyone of the Nokia developers give us some more hints on the head set topic please? Can we only expect that to work when the 2006 software edition will be released or will the head set support be included in an earlier firmware update? This missing feature is very much appreciated! Greets, Jonek. ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
Razvan Dragomirescu wrote: BTW, did anyone notice the following lines in the dmesg output on the 770 in the 51-13 firmware? [4.037261] Bluetooth: L2CAP ver 2.7 [4.041015] Bluetooth: L2CAP socket layer initialized [4.046356] Bluetooth: SCO (Voice Link) ver 0.4 [4.051147] Bluetooth: SCO socket layer initialized [4.056365] Bluetooth: RFCOMM ver 1.5 [4.060272] Bluetooth: RFCOMM socket layer initialized [4.065704] Bluetooth: RFCOMM TTY layer initialized [4.070861] Bluetooth: BNEP (Ethernet Emulation) ver 1.2 [4.076477] Bluetooth: HIDP (Human Interface Emulation) ver 1.1 It mentions SCO. I'm not sure if that means anything or if this was present in the older versions of the firmware, I just thought it was interesting. Also, a few lines above the Bluetooth stuff, you can find: [3.814697] Advanced Linux Sound Architecture Driver Version 1.0.9rc2 (Thu Mar 24 10:33:39 2005 UTC). [3.828033] usbcore: registered new driver snd-usb-audio [3.833709] ALSA device list: [3.836822] #0: Dummy 1 USB Audio? Hmmh, interesting... may be anyone out there who has a usb headset can check if it is possible to use it. BTW: The same output already appears on .45-8 Anyway, I sort of get the feeling that Nokia is keeping so quiet about this mostly because this is something they want to release in the 2006 firmware and they most probably don't want anyone stealing their thunder and releasing a fully-working VoIP package for the 770 before that. With Asterisk and chan_bluetooth ported to the device, the 770 could become the ultimate VoIP phone. full ACK! Any clues yet from Nokia? :). I suppose: no! :-( Cheers, Timo ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
On Mon, 2006-01-09 at 20:04 -0700, Brad Midgley wrote: Johannes The two types of bluetooth audio are very different. You linked to a discussion about the other type. Sorry, I didn't made that clear enough. I was refering to the following said in http://article.gmane.org/gmane.linux.bluez.devel/6729 by Marcel Holtmann: The Nokia 770 is using a TI chip and basically nobody of us has real experiences with these chips. I have seen them in an iPAQ and now the 770, but that's it. Do you think Nokia is willing to donate some of the TI development kits to BlueZ? Especially the SCO and eSCO stuff needs a lot of testing and I would prefer to do it with an i386 or x86_86 based system. And the answer to that in http://article.gmane.org/gmane.linux.bluez.devel/6748 by Ville Tervo from Nokia: I'll try to arrange something. low-latency voice-quality mono audio uses a special transport (SCO) and is delivered from the bluetooth chip either over the regular data connection to the cpu (HCI) or it is connected to dedicated audio/analog hardware (PCM). The HCI formatting and negotiation differs from chip to chip and the linux driver is only complete for CSR chipsets. Thanks for the explanation - SCO is exectly what I need then. a2dp specifies one-way high-quality, traditionally stereo, audio. It is delivered over an L2CAP socket so linux can send and receive this audio with any bluetooth chip that has even the most basic support. So that is used for bluetooth stereo earphones to listen to e.g. CD music? We know what has to be done for a2dp. The SCO stuff is what I would like to see help from Nokia on. I would hope they can help us with the HCI interaction with the SCO transport since that gives us the most generic control over the audio stream. Thanks for that details! Jonek ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
Razvan [4.046356] Bluetooth: SCO (Voice Link) ver 0.4 [4.051147] Bluetooth: SCO socket layer initialized this will be printed both for adapters with and without sco support. The driver does not detect and disable the interface on unsupported hardware. (Although it should--we get questions all the time about everything working right up to the point that they get silence on the connection instead of audio) Brad ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Brad Midgley schrieb: Razvan [4.046356] Bluetooth: SCO (Voice Link) ver 0.4 [4.051147] Bluetooth: SCO socket layer initialized this will be printed both for adapters with and without sco support. The driver does not detect and disable the interface on unsupported hardware. (Although it should--we get questions all the time about everything working right up to the point that they get silence on the connection instead of audio) Umm... to be more precise this is just the output from the SCO kernel driver not from the HCI driver. So the Bluetooth stack, according to this message, now supports handling of SCO traffic (kernel modules sco.ko). But this does not mean that the HCI driver for the specific Bluetooth module in use can handle it (kernel modules hci_* and friends). Those are two distinct things... Brad Cheers nils faerber - -- kernel concepts Tel: +49-271-771091-12 Dreisbachstr. 24 Fax: +49-271-771091-19 D-57250 Netphen Mob: +49-176-21024535 - -- -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.1 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDw+nrJXeIURG1qHgRAvEOAJ92LOph0Rm6YjwPtgROcFCC6SW9GwCgvKeK mKcAe1fz3cWaWYiNw46IvnA= =gEpd -END PGP SIGNATURE- ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
On Tue, 2005-12-20 at 10:16 -0700, Brad Midgley wrote: I'm overseeing the bluetooth audio on linux project... Linux only supports SCO transfers for CSR chips. To use the current btsco stuff, Nokia is going to have to contribute a SCO driver to the kernel for whatever bluetooth chip they put in the 770. I found some further info at: http://thread.gmane.org/gmane.linux.bluez.devel/6713 Can anyone of the Nokia developers give us some more hints on the head set topic please? Can we only expect that to work when the 2006 software edition will be released or will the head set support be included in an earlier firmware update? This missing feature is very much appreciated! Greets, Jonek. ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
Johannes The two types of bluetooth audio are very different. You linked to a discussion about the other type. low-latency voice-quality mono audio uses a special transport (SCO) and is delivered from the bluetooth chip either over the regular data connection to the cpu (HCI) or it is connected to dedicated audio/analog hardware (PCM). The HCI formatting and negotiation differs from chip to chip and the linux driver is only complete for CSR chipsets. a2dp specifies one-way high-quality, traditionally stereo, audio. It is delivered over an L2CAP socket so linux can send and receive this audio with any bluetooth chip that has even the most basic support. We know what has to be done for a2dp. The SCO stuff is what I would like to see help from Nokia on. I would hope they can help us with the HCI interaction with the SCO transport since that gives us the most generic control over the audio stream. Brad On Tue, 2005-12-20 at 10:16 -0700, Brad Midgley wrote: I'm overseeing the bluetooth audio on linux project... Linux only supports SCO transfers for CSR chips. To use the current btsco stuff, Nokia is going to have to contribute a SCO driver to the kernel for whatever bluetooth chip they put in the 770. I found some further info at: http://thread.gmane.org/gmane.linux.bluez.devel/6713 Can anyone of the Nokia developers give us some more hints on the head set topic please? Can we only expect that to work when the 2006 software edition will be released or will the head set support be included in an earlier firmware update? This missing feature is very much appreciated! Greets, Jonek. ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
On Mon, Jan 09, 2006 at 08:04:35PM -0700, Brad Midgley wrote: low-latency voice-quality mono audio uses a special transport (SCO) and is delivered from the bluetooth chip either over the regular data connection to the cpu (HCI) or it is connected to dedicated audio/analog hardware (PCM). The HCI formatting and negotiation differs from chip to chip and the linux driver is only complete for CSR chipsets. Hmm. Linux support aside, does this mean I'm never going to find a bt headset with both a mic for voice and high quality stereo playback for music in the same device? More or less what all the game consoles use, for example? -r ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
Ralph Hmm. Linux support aside, does this mean I'm never going to find a bt headset with both a mic for voice and high quality stereo playback for music in the same device? More or less what all the game consoles use, for example? I assumed you're aware that a lot of the stereo sets will switch into low-quality 2-way mode. It's the simultaneous stereo/mic that no one can do now. Brad ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
On Mon, Jan 09, 2006 at 08:29:38PM -0700, Brad Midgley wrote: The latency for every stereo set out there is so bad (500ms!) that you'd lose every game or just throw yourself out the nearest window. Oh dear. And I thought USB audio was bad... I wasn't actually aware that there were dual mode stereo/interactive headsets, but I see plantronics is selling one now. Clever how it's spun as a feature (Switch seamlessly between your phone and music from your stereo!) and not a bug. Is there a bandwidth problem, or just people being silly with the design? -r ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
Re: [maemo-developers] Bluetooth headset - not really working?
Razvan This seems to have been reported before (not for the 770): http://sourceforge.net/tracker/index.php?func=detailaid=1273754group_id=116589atid=678258 http://sourceforge.net/tracker/index.php?func=detailaid=1273754group_id=116589atid=678258 . However, the solution pskey mapsco 0 only seems to work with CSR Bluetooth chips, and the 770 has a TI chip. I'm overseeing the bluetooth audio on linux project... Linux only supports SCO transfers for CSR chips. To use the current btsco stuff, Nokia is going to have to contribute a SCO driver to the kernel for whatever bluetooth chip they put in the 770. It's possible that they will route SCO to PCM hardware (direct to audio hardware or even the dsp) rather than HCI (to the cpu). If this is the case, btsco etc will need a little hacking to work that way. (Or even better, to be rewritten) Brad ___ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers