Fix MIME type comparisons to be case-insensitive

mediaengine.go

@@ -240,7 +240,7 @@ func (m *MediaEngine) RegisterDefaultCodecs() error {
 func (m *MediaEngine) addCodec(codecs []RTPCodecParameters, codec RTPCodecParameters) ([]RTPCodecParameters, error) {
 	for _, c := range codecs {
 		if c.PayloadType == codec.PayloadType {
-			if c.MimeType == codec.MimeType &&
+			if strings.EqualFold(c.MimeType, codec.MimeType) &&
 				fmtp.ClockRateEqual(c.MimeType, c.ClockRate, codec.ClockRate) &&
 				fmtp.ChannelsEqual(c.MimeType, c.Channels, codec.Channels) {
 				return codecs, nil
@@ -798,7 +798,7 @@ func payloaderForCodec(codec RTPCodecCapability) (rtp.Payloader, error) {
 
 func (m *MediaEngine) isRTXEnabled(typ RTPCodecType, directions []RTPTransceiverDirection) bool {
 	for _, p := range m.getRTPParametersByKind(typ, directions).Codecs {
-		if p.MimeType == MimeTypeRTX {
+		if strings.EqualFold(p.MimeType, MimeTypeRTX) {
 			return true
 		}
 	}
@@ -808,7 +808,7 @@ func (m *MediaEngine) isRTXEnabled(typ RTPCodecType, directions []RTPTransceiver
 
 func (m *MediaEngine) isFECEnabled(typ RTPCodecType, directions []RTPTransceiverDirection) bool {
 	for _, p := range m.getRTPParametersByKind(typ, directions).Codecs {
-		if strings.Contains(p.MimeType, MimeTypeFlexFEC) {
+		if strings.Contains(strings.ToLower(p.MimeType), MimeTypeFlexFEC) {
 			return true
 		}
 	}

mediaengine_test.go

@@ -575,6 +575,7 @@ func TestMediaEngineHeaderExtensionDirection(t *testing.T) {
 
 // If a user attempts to register a codec twice we should just discard duplicate calls.
 func TestMediaEngineDoubleRegister(t *testing.T) {
+	t.Run("Same Codec", func(t *testing.T) {
 		mediaEngine := MediaEngine{}
 
 		assert.NoError(t, mediaEngine.RegisterCodec(
@@ -590,6 +591,55 @@ func TestMediaEngineDoubleRegister(t *testing.T) {
 			}, RTPCodecTypeAudio))
 
 		assert.Equal(t, len(mediaEngine.audioCodecs), 1)
+	})
+
+	t.Run("Case Insensitive Audio Codec", func(t *testing.T) {
+		mediaEngine := MediaEngine{}
+
+		assert.NoError(t, mediaEngine.RegisterCodec(
+			RTPCodecParameters{
+				RTPCodecCapability: RTPCodecCapability{"audio/OPUS", 48000, 0, "", nil},
+				PayloadType:        111,
+			}, RTPCodecTypeAudio))
+
+		assert.NoError(t, mediaEngine.RegisterCodec(
+			RTPCodecParameters{
+				RTPCodecCapability: RTPCodecCapability{"audio/opus", 48000, 0, "", nil},
+				PayloadType:        111,
+			}, RTPCodecTypeAudio))
+
+		assert.Equal(t, len(mediaEngine.audioCodecs), 1)
+	})
+
+	t.Run("Case Insensitive Video Codec", func(t *testing.T) {
+		mediaEngine := MediaEngine{}
+
+		assert.NoError(t, mediaEngine.RegisterCodec(
+			RTPCodecParameters{
+				RTPCodecCapability: RTPCodecCapability{strings.ToUpper(MimeTypeRTX), 90000, 0, "", nil},
+				PayloadType:        98,
+			}, RTPCodecTypeVideo))
+		assert.NoError(t, mediaEngine.RegisterCodec(
+			RTPCodecParameters{
+				RTPCodecCapability: RTPCodecCapability{MimeTypeRTX, 90000, 0, "", nil},
+				PayloadType:        98,
+			}, RTPCodecTypeVideo))
+		assert.NoError(t, mediaEngine.RegisterCodec(
+			RTPCodecParameters{
+				RTPCodecCapability: RTPCodecCapability{strings.ToUpper(MimeTypeFlexFEC), 90000, 0, "", nil},
+				PayloadType:        100,
+			}, RTPCodecTypeVideo))
+		assert.NoError(t, mediaEngine.RegisterCodec(
+			RTPCodecParameters{
+				RTPCodecCapability: RTPCodecCapability{MimeTypeFlexFEC, 90000, 0, "", nil},
+				PayloadType:        100,
+			}, RTPCodecTypeVideo))
+		assert.Equal(t, len(mediaEngine.videoCodecs), 2)
+		isRTX := mediaEngine.isRTXEnabled(RTPCodecTypeVideo, []RTPTransceiverDirection{RTPTransceiverDirectionRecvonly})
+		assert.True(t, isRTX)
+		isFEC := mediaEngine.isFECEnabled(RTPCodecTypeVideo, []RTPTransceiverDirection{RTPTransceiverDirectionRecvonly})
+		assert.True(t, isFEC)
+	})
 }
 
 // If a user attempts to register a codec with same payload but with different