[maemo-developers] [maemo-developers] Bluetooth Headset Support - Status update?

From: Brad Midgley bmidgley at xmission.com
Date: Sun Jan 14 05:21:12 EET 2007

> I'm pretty sure that you could write an A2DP music player that worked on
> the 770 without any help from Nokia. It wouldn't be nicely integrated,
> but it should work. I tested an app awhile ago, and got music coming out
> of my headset, it was just not real time - a second of music, 5 seconds
> silence, etc.
> The reason for this is that it needed to transcode the music into a
> different CODEC, for which there was no integer version available.

you must have tried our sbc encoder before any optimization. we have a
version that runs ok* in 32 bits that should execute in realtime without
burning up too much battery life.

> you were to, say, just store all your music in that format, transcoding
> as you uploaded to the 770, then no problem.

sbc typically takes twice the space of mp3 and then you'd need to build
an sbc decoder into gstreamer to play your files through wired audio.

fyi, there are headsets out there that have an mp3 decoder. our a2play
test app at least recognizes when the mp3 decoder is present even though
it doesn't try to use it.

> Thus, there's often more config and poking needed to get the chipset
> into the right mode.
> Does anybody know if the N800 uses the same Bluetooth chipset as the 770?

it's a bluecore4. you could use bccmd to route its audio to hci. if you
do mess around with bccmd, i'd recommend you make all changes to ram and
just don't even bother with the permanent settings. it would be so sad
to brick the bluetooth adapter in a new n800.


* resulting audio is not very loud and occasionally makes a "pop" sound
on high-volume input. 64-bit version runs without these problems.

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