[pulseaudio-discuss] SBC XQ for PA 13.0
h1p8r10n at yandex.com
Mon Dec 9 12:53:31 UTC 2019
09.12.2019, 12:47, "Andrey Semashev" <andrey.semashev at gmail.com>:
> On 2019-12-09 14:39, Pali RohÃ¡r wrote:
>> Â On Monday 09 December 2019 14:32:52 Andrey Semashev wrote:
>>> Â I have another piece of feedback to provide. Sometimes I experience audio
>>> Â dropouts. Sometimes in both left and right headphones, sometimes just one.
>>> Â In particular, I noticed this happen when I have a Bluetooth-connected
>>> Â DualShock 4 gamepad connected and playing games, but it also happens without
>>> Â it, although less often.
>>> Â I assume this is caused by Bluetooth bandwidth limitation. Note that EOZ Air
>>> Â are "truly wireless" (i.e. the two headphones connect wirelessly), and I
>>> Â have multiple WiFi networks available (one access point in the same room as
>>> Â the Bluetooth transmitter, a few others behind walls). I expect 2.4 GHz
>>> Â radio to be rather crowded. The gamepad and the headphones are in the same
>>> Â room as the Bluetooth transmitter, in clear direct visibility, so it can't
>>> Â get better than that.
>> Â Yes, 2.4 GHz is shared by both Bluetooth and WiFi, so it may be a
>> Â problem.
>>> Â I can see Pali's patches offer reduce_encoder_bitrate API that is supposed
>>> Â to mitigate this problem, but both SBC XQ profiles don't allow bitrate
>>> Â reduction.
>> Â Yes, SBC XQ is there the highest available quality profile of SBC.
>>> Â I think, SBC XQ desperately needs to support bitrate reduction,
>> Â No, this is main reason for usage of SBC XQ it is high quality codec.
>> Â SBC XQ needs high bitrate by its definition.
>>> Â as the codec with the highest bitrate out of all. Users might actually have
>>> Â reduced experience due to audio dropouts compared to the previously
>>> Â supported SBC HQ.
>> Â If you cannot use high bitrate codecs, then do not use high bitrate
>> Â codecs. There are other profiles of SBC which lower bitpool value and
>> Â therefore lower bitrate. E.g. SBC MQ or SBC LQ (medium and low quality).
>> Â Or you can use SBC in automatic mode where bitrate is automatically
>> Â decreased.
> As a user, I don't know whether I can use SBC XQ. I don't know whether
> its bitrate will fit in my radio conditions. If my device happens to
> support SBC XQ, that is the codec that will get picked upon connection.
> Please, correct me if I'm wrong, but I don't see a way to influence that.
> SBC XQ is high quality and high bitrate, true, but PA should adapt to
> the actual use conditions. More so if it actually has the means to do
> so. If PA detects that SBC XQ does not fit in BT bandwidth, it should
> gradually drop quality.
Please take a look at the many discussions, experiments, specifications analysis and calculations about
SBC XQ, before posting this kind of complaint. You make devs waste a lot of time at this point of implementation.
> pulseaudio-discuss mailing list
> pulseaudio-discuss at lists.freedesktop.org
More information about the pulseaudio-discuss