Enable stereo Opus for cloud gaming. (#181)

Author: jianjunz

BUILD.gn

@@ -478,6 +478,10 @@ config("common_config") {
       "/U_UNICODE",
     ]
   }
+
+  if (owt_cloud_gaming) {
+    defines += [ "OWT_CLOUD_GAMING" ]
+  }
 }
 
 config("common_objc") {

api/audio_codecs/opus/audio_decoder_opus.cc

@@ -44,6 +44,9 @@ absl::optional<AudioDecoderOpus::Config> AudioDecoderOpus::SdpToConfig(
         return absl::nullopt;  // Bad stereo parameter.
       }
     }
+#ifdef OWT_CLOUD_GAMING
+    return 2;
+#endif
     return 1;  // Default to mono.
   }();
   if (absl::EqualsIgnoreCase(format.name, "opus") &&

api/transport/bitrate_settings.h

@@ -42,7 +42,11 @@ struct BitrateConstraints {
   int max_bitrate_bps = -1;
 
  private:
+#ifdef OWT_CLOUD_GAMING
+  static constexpr int kDefaultStartBitrateBps = 5000000;
+#else
   static constexpr int kDefaultStartBitrateBps = 300000;
+#endif
 };
 
 }  // namespace webrtc