Re: [Bluez-devel] audio problems with a2play

Brad Midgley
2004-11-23T03:49:05Z

Henryk,

Are you saying the problem is in a2play or in hcidump?

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.

Are these backwards then?

s_config.sbc_elements.channel_mode = 1 << sbc_info.channel_mode;
s_config.sbc_elements.frequency = 1 << sbc_info.sampling_frequency;
s_config.sbc_elements.allocation_method =
1 << sbc_info.allocation_method;
s_config.sbc_elements.subbands = 1 << sbc_info.subbands;
s_config.sbc_elements.block_length = 1 << sbc_info.blocks;

Brad

Henryk Plötz wrote:
> Moin,
>
> Hmm, If I'm not mistaken a2play has even other problems. I tried to play
> sbc_test_01.sbc (for a start) through it while doing hcidump -x (the
> old hcidump, that is). When doing the set configuration hcidump said
>
> < ACL data: handle 0x002b flags 0x02 dlen 18
> L2CAP(d): cid 0x40 len 14 [psm 25]
> AVDTP(s): Set config cmd: transaction 0
> 04 04 01 00 07 06 00 00 81 86 02 FA
>
> which decodes as
> ACP SEID = 1 (OK)
> INT SEID = 1 (OK)
> Media transport capability (OK)
> Media Codec capability
> Audio (OK)
> SBC (OK)
> Sampling frequency = 16kHz (should be 48)
> Channel mode = Joint stereo (should be mono)
> Block length = 4 (should be 16)
> Subbands = 8 (should be 4)
> Allocation method = SNR (OK)
> Bitspool = 2 to 250 (OK)
>
> As you can see the only correct parameter (apart from the hardwired
> ones) is the allocation method. All others seem to be kind of bit
> reversed. As a side note: The new hcidump AVDTP parser has the same
> problem.
>