When using the VOLUME command to change volume I’m observing that the command will only report success once the A2DP stream has indicated a start even though a A2DP link is open. Please can you confirm if this is expected behaviour?
The Melody commands documentation does not give any indication that for the VOLUME command to be successful it requires to be in the A2DP_STREAM_START state. Also, the documentation uses the term link in relation to volume changes, to me this implies that once a A2DP link is open then volume changes should be successful.
Here is a simple log showing volume changes (both error and success):
BlueCreation Copyright 2017 Melody Audio V6.1.5 HD Build: 1496941831 Ready OPEN_OK 10 A2DP 88CB8791F5C3 ROLE_OK 88CB8791F5C3 S OPEN_OK 11 AVRCP 88CB8791F5C3 ABS_VOL 11 127 get bt_vol_config BT_VOL_CONFIG=A A 10 0 OK volume 01 ANLG A 10 A2DP F OK volume 10 8 ERROR 0x0013 A2DP_STREAM_START 10 AVRCP_PLAY 11 volume 10 8 OK A2DP_STREAM_SUSPEND 10 AVRCP_STOP 11 A2DP_STREAM_START 10 AVRCP_PLAY 11 AVRCP_STOP 11 A2DP_STREAM_SUSPEND 10 volume 10 4 ERROR 0x0013