fix: Fix can't open mic alone when built-in AEC is enabled. (#29)

Author: cloudwebrtc

audio/audio_state.cc

@@ -103,6 +103,14 @@ void AudioState::AddSendingStream(webrtc::AudioSendStream* stream,
   if (!adm->Recording()) {
     if (adm->InitRecording() == 0) {
       if (recording_enabled_) {
+#if defined(WEBRTC_WIN)
+        if (adm->BuiltInAECIsAvailable() && !adm->Playing()) {
+          if (!adm->PlayoutIsInitialized()) {
+            adm->InitPlayout();
+          }
+          adm->StartPlayout();
+        }
+#endif
         adm->StartRecording();
       }
     } else {