Hi Community, I have two questions about how bluez would invoke the SelectConfiguration provided by the registered media endpoint. I am using bluez-4.101. 1. With a bluetooth speaker that supports A2DP, from logs of my program manipulating bluez's dbus API I saw bluez had invoked the SelectConfiguration method with parameters describing the capability of the bluetooth speaker, so that my program could send back bluez a dbus message with my preferred settings, e.g., 48k Hz frequency and Mono. However, when I tested with a bluetooth headset that only supports HFP/HSP, bluez seems not calling SelectConfiguration, but SetConfiguration directly. Furthermore, the "Configuration" in the parameters of the SetConfiguration is an empty array: object path "/org/bluez/3765/hci1/dev_1C_48_F9_AD_19_EE/fd5" array [ dict entry( string "Device" variant object path "/org/bluez/3765/hci1/dev_1C_48_F9_AD_19_EE" ) dict entry( string "UUID" variant string "0000111f-0000-1000-8000-00805f9b34fb" ) dict entry( string "Codec" variant byte 0 ) dict entry( string "Configuration" variant array [ ] ) dict entry( string "NREC" variant boolean true ) dict entry( string "InbandRingtone" variant boolean true ) dict entry( string "Routing" variant string "HCI" ) ] I am wondering if this is the reason that makes bluez not calling SelectConfiguration for such bluetooth headsetl in the first place, since it is not configurable at all. Please confirm whether this is how bluez works. Then how can I further know the frequency and the number of channel supported by my bluetooth headset? (from my testing with different wav files it seems only plays well format of S16_LE, 8kHz, mono) 2. For my bluetooth speaker that is configurable on frequency and the number of channel, if I specify a particular configuration, then it won't support other wave files with different configurations. For example, if I specify the sample rate used by it to be 48k Hz, but I play a wav file of 8k Hz instead, then it will be played 6 times faster than expected, only a short screaming is heard. Moreover, during testing I found that if I specify more than one bit for frequency or channel_mode for example in the return message of SelectConfiguration, the connection will simply fail. So, does this mean my program, or the audio server, would have to convert the format of sound files to the frequency, channel_mode etc used by the remote bluetooth configured through SelectConfiguration before playing sound files? Many thanks for any comments! Cheers, Harry -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html