There are multiple definitions of SBC XQ, but in all cases this is SBC codec in Dual Channel mode, 8 bands, block length 16, allocation method Loudness, with bitpool adjusted to match target bitrates.
Most commonly chosen bitrates and reasons are:
- 453000 - this yields most efficient packing of frames on Android for bluetooth EDR 2mbps
- 512000 - this looks to be old limit stated in bluetooth documents
- 552000 - this yields most efficient packing of frames on Android for bluetooth EDR 3mbps
Efficient packing considerations do not apply on Linux (yet?) but still we can gain from increased bitrate.
Desired SBC bitpool value is calculated from target bitrate limit; calculation could be open-coded if needed, no call to sbc library is actually required as bitrate formula is known from A2DP spec.
Issue ref #1092 (closed)