Re: [Bluez-devel] more encoder stuff

Marcel Holtmann
2004-11-25T06:02:19Z

Hi Brad,

> It was fantastic listening to my headset on the bus today. I didn't have
> to deal with the bluetake dongle at all... very nice.

I updated the a2play program to detect my buggy Aiptek headphone and
activate the non specification conform use of SBC audio. Actually I did
changes at many places in the code, because the parameter sets of some
functions had to be changed. And I also cleaned up some mess that was
generated by Lindent.

> What should I be using if I want to encode live from the computer's
> line-in? (I want to see if encoding on the computer results in shorter
> latency than the bluetake dongle. Watching TV with the headset is
> currently not all that fun because of the delay.)

Maybe something like this might work:

arecord -f cd -t au /dev/stdout | sbcenc - | a2play <bdaddr> -

> We should get Sonorix to send us a headset for testing. Have you had
> much luck with vendor cooperation, Marcel? Right now in a2play we sort
> of assume the headset will only report one codec and I suspect they
> support mp3 natively. (It's possible they are pulling tricks like
> transcoding into SBC before uploading mp3's to the headset's flash
> memory I guess.)

In the past I only talked to Aiptek and they won't send me a headphone
for free and so I finally bought one by myself. Right now I think that I
also need the Bluetake headphone, but I don't like to buy another one by
myself. The Sonorix and also the Logitech (sold as HP model for iPAQs at
the moment) are two other interesting headphones. In general it is no
problem for the companies to donate a bunch of their devices, but you
need to talk to right people. As you might have seen on the BlueZ page
there are some friendly companies. They have no problems in giving away
their hardware to developers for free.

http://www.bluez.org/sponsors.html

May you simply try to contact Sonorix and put me on CC. If they care
about Linux and Bluetooth they should really know my name. And I think
we need actually three of these headphones. One for each of us.

Another way is if people like our work they may donate some money or buy
one of these devices and send it to us. Anyone feel free to contact me
by private email about this.

To answer your MP3 question, I don't know. At the moment I don't expect
any headphones with more than one codec or even with more than one SEID.
The biggest problem might be that the MP3 codec is not license free, but
SBC is. The total cost calculations for software and hardware (including
the firmware) are different.

Regards

Marcel