Wire up FlexFEC in VideoEngine2.

webrtc/config.cc

Index: webrtc/config.cc
diff --git a/webrtc/config.cc b/webrtc/config.cc
index 4b437e264d3dcebd675fb7c41ce4175697ed532c..313390494f66f8cbb4409560da41d493df43a95f 100644
--- a/webrtc/config.cc
+++ b/webrtc/config.cc
@@ -50,6 +50,18 @@ std::string FlexfecConfig::ToString() const {
   return ss.str();
 }
 
+bool FlexfecConfig::IsValid() const {
+  if (flexfec_payload_type < 0)

[magjed_webrtc, 2016/11/17 13:37:19]

Isn't the valid payload type range 96-127 for this?

[brandtr, 2016/11/17 17:28:57]

Yes, you are right. My intention with this function is however to check if we
have enough information to enable FlexFEC/if we should enable FlexFEC. The way
to signal that we do not want to enable FlexFEC is to send a payload type of -1,
hence this check. To make my intentions clearer, I will rename this function and
remove the 127 check.

(The validity of the payload type values is checked in VideoSendStream. There we
however allow anything in the range 0-127. I'll check with danilchap if we
should tighten that.)

+    return false;
+  if (flexfec_payload_type > 127)
+    return false;
+  if (flexfec_ssrc == 0)
+    return false;
+  if (protected_media_ssrcs.size() != 1)
+    return false;
+  return true;
+}
+
 std::string RtpExtension::ToString() const {
   std::stringstream ss;
   ss << "{uri: " << uri;