When using A2DP with SBC codec resulting bitrate mainly depends on bitpool parameter
Now on my Linux machine, my goal is to know bitpool value when playing audio to a Bluetooth A2DP receiver. With wireshark I've captured frames when connecting to this bluetooth receiver, in AVDTP protocol frames I found frame getting/setting bluetooth receiver capabilities. I can see actual A2Dp codec configuration :
Service: Media Codec - Audio SBC (44100 | JointStereo | block: 16 | subbands: 8 | allocation: Loudness | bitpool: 2..53)
I got bitpool range value, but when playing, this value can change when radio link is bad...
How can I get current bitpool when playing?
I've captured bluetooth frames before and during playing, but I did not found any frame giving bitpool current value (when playing most of frames are HCI H4 frames)