Re: [Bluez-devel] audio problems with a2play

Marcel Holtmann
2004-11-23T09:34:55Z

Hi Henryk,

> > I don't know the "real" mapping between the indexed settings in the
> > sbc file format and the bitmapped settings/capabilities we use with
> > the a2dp protocol.
>
> It's on page 20 of the A2DP spec where it says, for example, that the
> first byte of the codec specific information elements for SBC encodes
> the sampling frequency in the upper half of the byte and the channel
> mode in the lower half. The first byte that a2play sends for
> sbc_test_01.sbc (which is 48 kHz mono) is 0x81, so bits 7 (0x80) and 0
> (0x01) are set. Bit 7 set means 16 kHz (section 4.3.2.1), bit 0 set
> means joint stereo (section 4.3.2.2). The correct value for this byte
> would be 0x18 (bits 4 and 3 set).
>
> Similarly the second byte (currently 0x86) should be 0x1a (bits 4, 3 and
> 1 set).

may you check the hcidump from CVS again if it is now correct? If yes,
then I will release another version.

Regards

Marcel