Remove un-preferred codecs for android firefox (#2183)

* Remove un-preferred codecs for android firefox

Android firefox don't comply with the codec order in answer sdp and
has problem to publish h.264, remove other codecs to fix this.

* false(false) is true

pkg/rtc/clientinfo.go

@@ -37,6 +37,10 @@ func (c ClientInfo) isGo() bool {
 	return c.ClientInfo != nil && c.ClientInfo.Sdk == livekit.ClientInfo_GO
 }
 
+func (c ClientInfo) isLinux() bool {
+	return c.ClientInfo != nil && strings.EqualFold(c.ClientInfo.Os, "linux")
+}
+
 func (c ClientInfo) SupportsAudioRED() bool {
 	return !c.isFirefox() && !c.isSafari()
 }
@@ -80,6 +84,10 @@ func (c ClientInfo) SupportsChangeRTPSenderEncodingActive() bool {
 	return !c.isFirefox()
 }
 
+func (c ClientInfo) ComplyWithCodecOrderInSDPAnswer() bool {
+	return !(c.isLinux() && c.isFirefox())
+}
+
 // compareVersion compares a semver against the current client SDK version
 // returning 1 if current version is greater than version
 // 0 if they are the same, and -1 if it's an earlier version

pkg/rtc/participant_sdp.go

@@ -180,7 +180,10 @@ func (p *ParticipantImpl) setCodecPreferencesVideoForPublisher(offer webrtc.Sess
 			}
 
 			unmatchVideo.MediaName.Formats = append(unmatchVideo.MediaName.Formats[:0], preferredCodecs...)
-			unmatchVideo.MediaName.Formats = append(unmatchVideo.MediaName.Formats, leftCodecs...)
+			// if the client don't comply with codec order in SDP answer, only keep preferred codecs to force client to use it
+			if p.params.ClientInfo.ComplyWithCodecOrderInSDPAnswer() {
+				unmatchVideo.MediaName.Formats = append(unmatchVideo.MediaName.Formats, leftCodecs...)
+			}
 		}
 	}