Move defaultSrtpProtectionProfiles to constants.go

If a user is curious about the default value when configuring
SetSRTPProtectionProfiles this makes it easier to find.

Author: Sean-Der

constants.go

@@ -1,5 +1,7 @@
 package webrtc
 
+import "github.com/pion/dtls/v2"
+
 const (
 	// Unknown defines default public constant to use for "enum" like struct
 	// comparisons when no value was defined.
@@ -23,3 +25,7 @@ const (
 
 	rtpOutboundMTU = 1200
 )
+
+func defaultSrtpProtectionProfiles() []dtls.SRTPProtectionProfile {
+	return []dtls.SRTPProtectionProfile{dtls.SRTP_AEAD_AES_128_GCM, dtls.SRTP_AES128_CM_HMAC_SHA1_80}
+}

dtlstransport.go

@@ -306,7 +306,7 @@ func (t *DTLSTransport) Start(remoteParameters DTLSParameters) error {
 					return t.api.settingEngine.srtpProtectionProfiles
 				}
 
-				return []dtls.SRTPProtectionProfile{dtls.SRTP_AEAD_AES_128_GCM, dtls.SRTP_AES128_CM_HMAC_SHA1_80}
+				return defaultSrtpProtectionProfiles()
 			}(),
 			ClientAuth:         dtls.RequireAnyClientCert,
 			LoggerFactory:      t.api.settingEngine.LoggerFactory,

settingengine.go

@@ -72,7 +72,8 @@ func (e *SettingEngine) DetachDataChannels() {
 	e.detach.DataChannels = true
 }
 
-// SetSRTPProtectionProfiles overrides default srtp protection profiles
+// SetSRTPProtectionProfiles allows the user to override the default SRTP Protection Profiles
+// The default srtp protection profiles are provided by the function `defaultSrtpProtectionProfiles`
 func (e *SettingEngine) SetSRTPProtectionProfiles(profiles ...dtls.SRTPProtectionProfile) {
 	e.srtpProtectionProfiles = profiles
 }