2012/3/13 Siarhei Siamashka <siarhei.siamashka@xxxxxxxxx>:
> On Tue, Mar 13, 2012 at 3:48 AM, qduaty <qduaty@xxxxxxxxx> wrote:
>> 2011/10/18 Siarhei Siamashka <siarhei.siamashka@xxxxxxxxx>:
> Thanks for testing! One more experiment would be very much welcome. I
> wonder if just defining SBC_HIGH_PRECISION without doing anything else
> would have any noticeable effect on audio quality in listening tests.
Well, before I move on, there is one thing that makes me sad:
< ACL data: handle 1 flags 0x02 dlen 7
L2CAP(d): cid 0x006d len 3 [psm 25]
AVDTP(s): Capabilities cmd: transaction 10 nsp 0x00
ACP SEID 1
> HCI Event: Number of Completed Packets (0x13) plen 5
handle 1 packets 1
> ACL data: handle 1 flags 0x02 dlen 16
L2CAP(d): cid 0x0040 len 12 [psm 25]
AVDTP(s): Capabilities rsp: transaction 10 nsp 0x00
Media Transport
Media Codec - SBC
44.1kHz
Stereo
16 Blocks
8 Subbands
Loudness
Bitpool Range 112-128
< ACL data: handle 1 flags 0x02 dlen 18
L2CAP(d): cid 0x006d len 14 [psm 25]
AVDTP(s): Set config cmd: transaction 11 nsp 0x00
ACP SEID 1 - INT SEID 2
Media Transport
Media Codec - SBC
44.1kHz
Stereo
16 Blocks
8 Subbands
Loudness
Bitpool Range 112-53
> HCI Event: Number of Completed Packets (0x13) plen 5
handle 1 packets 1
> ACL data: handle 1 flags 0x02 dlen 8
L2CAP(d): cid 0x0040 len 4 [psm 25]
AVDTP(s): Set config rej: transaction 11 nsp 0x00
Media Codec
Error code 204
The other device that tries to communicate at bitpool=112 and gives
up, is my phone. Now I'm listening to it with the headset and the
sound is perfectly clear, with no sign of that "analog" distortion I
mentioned earlier.
Bluez has MAX_BITPOOL=53 or 64 stored everywhere and who knows, maybe
it's even able to recover these magic numbers from bitrate. Should I
look for bitrate constant, like 320 or so?
> audio quality in the current bluez sbc decoder is
> far from perfect and the synthesis filter needs to be replaced first.
I'm not sure what you expect from sbcenc-sbcdec tests. Even if they
prove the encoding/decoding within Bluez has a reasonably good
quality, what then? Will it propagate among different devices,
bluetooth stacks?
Regards
--
Sebastian Olter
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