Android系统在VOICE_COMMUNICATION模式下视频通话，如主板没有语音通话模块，只有麦克风。这个时候app调用视频通话 对方接受不到声音。需要做如下修改：

--- a/frameworks/av/services/audiopolicy/enginedefault/src/Engine.cpp
+++ b/frameworks/av/services/audiopolicy/enginedefault/src/Engine.cpp
         // Allow only use of devices on primary input if in call and HAL does not support routing
         // to voice call path.
         if ((getPhoneState() == AUDIO_MODE_IN_CALL) &&
                 (availableOutputDevices.types() & AUDIO_DEVICE_OUT_TELEPHONY_TX) == 0) {
             sp<AudioOutputDescriptor> primaryOutput = outputs.getPrimaryOutput();
             availableDeviceTypes =
-                    availableInputDevices.getDevicesFromHwModule(primaryOutput->getModuleHandle())
-                    & ~AUDIO_DEVICE_BIT_IN;
+                    availableInputDevices.getDevicesFromHwModule(primaryOutput->getModuleHandle());
         }
 
         switch (mForceUse[AUDIO_POLICY_FORCE_FOR_COMMUNICATION]) {