来结贴啦。
模拟模式下切换到voip是没有声音的,因为相关的音频路径在代码中没有铺设。
这个在ADK Audio Source Application User Guide 中有说明:
The HFP profile is not intended for use in an Analogue or S/PDIF mode device. The audio associated
with the HFP profile is not routed, so is not audible at the Source application end or the remote end.