diff --git a/README.md b/README.md
index ad412e9a5254..ad312362baa2 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ Live streams can be published to the server with:
 |[WebRTC servers](#webrtc-servers)|WHEP|AV1, VP9, VP8, [H265](#supported-browsers), H264|Opus, G722, G711 (PCMA, PCMU)|
 |[RTSP clients](#rtsp-clients)|UDP, TCP, RTSPS|AV1, VP9, VP8, H265, H264, MPEG-4 Video (H263, Xvid), MPEG-1/2 Video, M-JPEG and any RTP-compatible codec|Opus, MPEG-4 Audio (AAC), MPEG-1/2 Audio (MP3), AC-3, G726, G722, G711 (PCMA, PCMU), LPCM and any RTP-compatible codec|
 |[RTSP cameras and servers](#rtsp-cameras-and-servers)|UDP, UDP-Multicast, TCP, RTSPS|AV1, VP9, VP8, H265, H264, MPEG-4 Video (H263, Xvid), MPEG-1/2 Video, M-JPEG and any RTP-compatible codec|Opus, MPEG-4 Audio (AAC), MPEG-1/2 Audio (MP3), AC-3, G726, G722, G711 (PCMA, PCMU), LPCM and any RTP-compatible codec|
-|[RTMP clients](#rtmp-clients)|RTMP, RTMPS, Enhanced RTMP|AV1, VP9, H265, H264|MPEG-4 Audio (AAC), MPEG-1/2 Audio (MP3), G711 (PCMA, PCMU), LPCM|
+|[RTMP clients](#rtmp-clients)|RTMP, RTMPS, Enhanced RTMP|AV1, VP9, H265, H264|Opus, MPEG-4 Audio (AAC), MPEG-1/2 Audio (MP3), G711 (PCMA, PCMU), LPCM|
 |[RTMP cameras and servers](#rtmp-cameras-and-servers)|RTMP, RTMPS, Enhanced RTMP|AV1, VP9, H265, H264|MPEG-4 Audio (AAC), MPEG-1/2 Audio (MP3), G711 (PCMA, PCMU), LPCM|
 |[HLS cameras and servers](#hls-cameras-and-servers)|Low-Latency HLS, MP4-based HLS, legacy HLS|AV1, VP9, [H265](#supported-browsers-1), H264|Opus, MPEG-4 Audio (AAC)|
 |[UDP/MPEG-TS](#udpmpeg-ts)|Unicast, broadcast, multicast|H265, H264, MPEG-4 Video (H263, Xvid), MPEG-1/2 Video|Opus, MPEG-4 Audio (AAC), MPEG-1/2 Audio (MP3), AC-3|
@@ -2438,9 +2438,10 @@ All the code in this repository is released under the [MIT License](LICENSE). Co
 |----|----|
 |[RTSP / RTP / RTCP specifications](https://github.com/bluenviron/gortsplib#specifications)|RTSP|
 |[HLS specifications](https://github.com/bluenviron/gohlslib#specifications)|HLS|
-|[RTMP](https://rtmp.veriskope.com/pdf/rtmp_specification_1.0.pdf)|RTMP|
-|[Enhanced RTMP v1](https://veovera.org/docs/enhanced/enhanced-rtmp-v1.pdf)|RTMP|
-|[Action Message Format](https://rtmp.veriskope.com/pdf/amf0-file-format-specification.pdf)|RTMP|
+|[Action Message Format - AMF 0](https://veovera.org/docs/legacy/amf0-file-format-spec.pdf)|RTMP|
+|[FLV](https://veovera.org/docs/legacy/video-file-format-v10-1-spec.pdf)|RTMP|
+|[RTMP](https://veovera.org/docs/legacy/rtmp-v1-0-spec.pdf)|RTMP|
+|[Enhanced RTMP v2](https://veovera.org/docs/enhanced/enhanced-rtmp-v2.pdf)|RTMP|
 |[WebRTC: Real-Time Communication in Browsers](https://www.w3.org/TR/webrtc/)|WebRTC|
 |[RFC8835, Transports for WebRTC](https://datatracker.ietf.org/doc/html/rfc8835)|WebRTC|
 |[RFC7742, WebRTC Video Processing and Codec Requirements](https://datatracker.ietf.org/doc/html/rfc7742)|WebRTC|
diff --git a/internal/protocols/rtmp/message/extended_mpeg2ts_sequence_start.go b/internal/protocols/rtmp/message/extended_mpeg2ts_sequence_start.go
deleted file mode 100644
index f599c3265649..000000000000
--- a/internal/protocols/rtmp/message/extended_mpeg2ts_sequence_start.go
+++ /dev/null
@@ -1,26 +0,0 @@
-package message
-
-import (
-	"fmt"
-
-	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
-)
-
-// ExtendedMPEG2TSSequenceStart is a MPEG2-TS sequence start extended message.
-type ExtendedMPEG2TSSequenceStart struct {
-	FourCC FourCC
-}
-
-func (m *ExtendedMPEG2TSSequenceStart) unmarshal(raw *rawmessage.Message) error {
-	if len(raw.Body) < 5 {
-		return fmt.Errorf("invalid body size")
-	}
-
-	m.FourCC = FourCC(raw.Body[1])<<24 | FourCC(raw.Body[2])<<16 | FourCC(raw.Body[3])<<8 | FourCC(raw.Body[4])
-
-	return fmt.Errorf("ExtendedMPEG2TSSequenceStart is not implemented yet")
-}
-
-func (m ExtendedMPEG2TSSequenceStart) marshal() (*rawmessage.Message, error) {
-	return nil, fmt.Errorf("TODO")
-}
diff --git a/internal/protocols/rtmp/message/message.go b/internal/protocols/rtmp/message/message.go
index 4d34d0334863..15c280889348 100644
--- a/internal/protocols/rtmp/message/message.go
+++ b/internal/protocols/rtmp/message/message.go
@@ -18,19 +18,15 @@ const (
 	TypeSetChunkSize     Type = 1
 	TypeAbortMessage     Type = 2
 	TypeAcknowledge      Type = 3
+	TypeUserControl      Type = 4
 	TypeSetWindowAckSize Type = 5
 	TypeSetPeerBandwidth Type = 6
-
-	TypeUserControl Type = 4
-
-	TypeCommandAMF3 Type = 17
-	TypeCommandAMF0 Type = 20
-
-	TypeDataAMF3 Type = 15
-	TypeDataAMF0 Type = 18
-
-	TypeAudio Type = 8
-	TypeVideo Type = 9
+	TypeAudio            Type = 8
+	TypeVideo            Type = 9
+	TypeDataAMF3         Type = 15
+	TypeDataAMF0         Type = 18
+	TypeCommandAMF3      Type = 17
+	TypeCommandAMF0      Type = 20
 )
 
 // UserControlType is a user control type.
@@ -47,27 +43,44 @@ const (
 	UserControlTypePingResponse     UserControlType = 7
 )
 
-// ExtendedType is a message extended type.
-type ExtendedType uint8
+// AudioExType is an audio message extended type.
+type AudioExType uint8
 
-// message extended types.
+// video message extended types.
 const (
-	ExtendedTypeSequenceStart        ExtendedType = 0
-	ExtendedTypeCodedFrames          ExtendedType = 1
-	ExtendedTypeSequenceEnd          ExtendedType = 2
-	ExtendedTypeFramesX              ExtendedType = 3
-	ExtendedTypeMetadata             ExtendedType = 4
-	ExtendedTypeMPEG2TSSequenceStart ExtendedType = 5
+	AudioExTypeSequenceStart      AudioExType = 0
+	AudioExTypeCodedFrames        AudioExType = 1
+	AudioExTypeSequenceEnd        AudioExType = 2
+	AudioExTypeMultichannelConfig AudioExType = 4
+	AudioExTypeMultitrack         AudioExType = 5
 )
 
-// FourCC is an identifier of a video codec.
+// VideoExType is a video message extended type.
+type VideoExType uint8
+
+// video message extended types.
+const (
+	VideoExTypeSequenceStart        VideoExType = 0
+	VideoExTypeCodedFrames          VideoExType = 1
+	VideoExTypeSequenceEnd          VideoExType = 2
+	VideoExTypeFramesX              VideoExType = 3
+	VideoExTypeMetadata             VideoExType = 4
+	VideoExTypeMPEG2TSSequenceStart VideoExType = 5
+	VideoExTypeMultitrack           VideoExType = 6
+)
+
+// FourCC is an identifier of a Extended-RTMP codec.
 type FourCC uint32
 
-// video codec identifiers.
+// codec identifiers.
 var (
+	// video
 	FourCCAV1  FourCC = 'a'<<24 | 'v'<<16 | '0'<<8 | '1'
 	FourCCVP9  FourCC = 'v'<<24 | 'p'<<16 | '0'<<8 | '9'
 	FourCCHEVC FourCC = 'h'<<24 | 'v'<<16 | 'c'<<8 | '1'
+
+	// audio
+	FourCCOpus FourCC = 'O'<<24 | 'p'<<16 | 'u'<<8 | 's'
 )
 
 // Message is a message.
diff --git a/internal/protocols/rtmp/message/acknowledge.go b/internal/protocols/rtmp/message/msg_acknowledge.go
similarity index 100%
rename from internal/protocols/rtmp/message/acknowledge.go
rename to internal/protocols/rtmp/message/msg_acknowledge.go
diff --git a/internal/protocols/rtmp/message/audio.go b/internal/protocols/rtmp/message/msg_audio.go
similarity index 100%
rename from internal/protocols/rtmp/message/audio.go
rename to internal/protocols/rtmp/message/msg_audio.go
diff --git a/internal/protocols/rtmp/message/msg_audio_ex_coded_frames.go b/internal/protocols/rtmp/message/msg_audio_ex_coded_frames.go
new file mode 100644
index 000000000000..28fd8607c840
--- /dev/null
+++ b/internal/protocols/rtmp/message/msg_audio_ex_coded_frames.go
@@ -0,0 +1,54 @@
+package message
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
+)
+
+// AudioExCodedFrames is a CodedFrames extended message.
+type AudioExCodedFrames struct {
+	ChunkStreamID   byte
+	DTS             time.Duration
+	MessageStreamID uint32
+	FourCC          FourCC
+	Payload         []byte
+}
+
+func (m *AudioExCodedFrames) unmarshal(raw *rawmessage.Message) error {
+	if len(raw.Body) < 6 {
+		return fmt.Errorf("not enough bytes")
+	}
+
+	m.ChunkStreamID = raw.ChunkStreamID
+	m.DTS = raw.Timestamp
+	m.MessageStreamID = raw.MessageStreamID
+	m.FourCC = FourCC(raw.Body[1])<<24 | FourCC(raw.Body[2])<<16 | FourCC(raw.Body[3])<<8 | FourCC(raw.Body[4])
+	m.Payload = raw.Body[5:]
+
+	return nil
+}
+
+func (m AudioExCodedFrames) marshalBodySize() int {
+	return 5 + len(m.Payload)
+}
+
+func (m AudioExCodedFrames) marshal() (*rawmessage.Message, error) {
+	body := make([]byte, m.marshalBodySize())
+
+	body[0] = (9 << 4) | byte(AudioExTypeCodedFrames)
+	body[1] = uint8(m.FourCC >> 24)
+	body[2] = uint8(m.FourCC >> 16)
+	body[3] = uint8(m.FourCC >> 8)
+	body[4] = uint8(m.FourCC)
+	copy(body[5:], m.Payload)
+
+	return &rawmessage.Message{
+		ChunkStreamID:   m.ChunkStreamID,
+		Timestamp:       m.DTS,
+		Type:            uint8(TypeAudio),
+		MessageStreamID: m.MessageStreamID,
+		Body:            body,
+	}, nil
+}
diff --git a/internal/protocols/rtmp/message/msg_audio_ex_multichannel_config.go b/internal/protocols/rtmp/message/msg_audio_ex_multichannel_config.go
new file mode 100644
index 000000000000..5cbd51d626a2
--- /dev/null
+++ b/internal/protocols/rtmp/message/msg_audio_ex_multichannel_config.go
@@ -0,0 +1,69 @@
+package message
+
+import (
+	"fmt"
+
+	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
+)
+
+// AudioExChannelOrder is an audio channel order.
+type AudioExChannelOrder uint8
+
+// audio channel orders.
+const (
+	AudioExChannelOrderUnspecified AudioExChannelOrder = 0
+	AudioExChannelOrderNative      AudioExChannelOrder = 1
+	AudioExChannelOrderCustom      AudioExChannelOrder = 2
+)
+
+// AudioExMultichannelConfig is a sequence start extended message.
+type AudioExMultichannelConfig struct {
+	ChunkStreamID       byte
+	MessageStreamID     uint32
+	FourCC              FourCC
+	AudioChannelOrder   AudioExChannelOrder
+	ChannelCount        uint8
+	AudioChannelMapping uint8  // only for AudioChannelOrder == AudioExChannelOrderCustom
+	AudioChannelFlags   uint32 // only for AudioChannelOrder == AudioExChannelOrderNative
+}
+
+func (m *AudioExMultichannelConfig) unmarshal(raw *rawmessage.Message) error {
+	if len(raw.Body) < 7 {
+		return fmt.Errorf("not enough bytes")
+	}
+
+	m.ChunkStreamID = raw.ChunkStreamID
+	m.MessageStreamID = raw.MessageStreamID
+	m.FourCC = FourCC(raw.Body[1])<<24 | FourCC(raw.Body[2])<<16 | FourCC(raw.Body[3])<<8 | FourCC(raw.Body[4])
+	m.AudioChannelOrder = AudioExChannelOrder(raw.Body[5])
+	m.ChannelCount = raw.Body[6]
+
+	switch m.AudioChannelOrder {
+	case AudioExChannelOrderCustom:
+		if len(raw.Body) != 8 {
+			return fmt.Errorf("invalid AudioExMultichannelConfig size")
+		}
+		m.AudioChannelMapping = raw.Body[7]
+
+	case AudioExChannelOrderNative:
+		if len(raw.Body) != 11 {
+			return fmt.Errorf("invalid AudioExMultichannelConfig size")
+		}
+		m.AudioChannelFlags = uint32(raw.Body[7])<<24 | uint32(raw.Body[8])<<16 |
+			uint32(raw.Body[9])<<8 | uint32(raw.Body[10])
+
+	case AudioExChannelOrderUnspecified:
+		if len(raw.Body) != 7 {
+			return fmt.Errorf("invalid AudioExMultichannelConfig size")
+		}
+
+	default:
+		return fmt.Errorf("invalid AudioChannelOrder")
+	}
+
+	return nil
+}
+
+func (m AudioExMultichannelConfig) marshal() (*rawmessage.Message, error) {
+	return nil, fmt.Errorf("TODO")
+}
diff --git a/internal/protocols/rtmp/message/msg_audio_ex_sequence_start.go b/internal/protocols/rtmp/message/msg_audio_ex_sequence_start.go
new file mode 100644
index 000000000000..dccf560e1fe8
--- /dev/null
+++ b/internal/protocols/rtmp/message/msg_audio_ex_sequence_start.go
@@ -0,0 +1,32 @@
+package message
+
+import (
+	"fmt"
+
+	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
+)
+
+// AudioExSequenceStart is a sequence start extended message.
+type AudioExSequenceStart struct {
+	ChunkStreamID   byte
+	MessageStreamID uint32
+	FourCC          FourCC
+	Config          []byte
+}
+
+func (m *AudioExSequenceStart) unmarshal(raw *rawmessage.Message) error {
+	if len(raw.Body) < 6 {
+		return fmt.Errorf("not enough bytes")
+	}
+
+	m.ChunkStreamID = raw.ChunkStreamID
+	m.MessageStreamID = raw.MessageStreamID
+	m.FourCC = FourCC(raw.Body[1])<<24 | FourCC(raw.Body[2])<<16 | FourCC(raw.Body[3])<<8 | FourCC(raw.Body[4])
+	m.Config = raw.Body[5:]
+
+	return nil
+}
+
+func (m AudioExSequenceStart) marshal() (*rawmessage.Message, error) {
+	return nil, fmt.Errorf("TODO")
+}
diff --git a/internal/protocols/rtmp/message/command_amf0.go b/internal/protocols/rtmp/message/msg_command_amf0.go
similarity index 100%
rename from internal/protocols/rtmp/message/command_amf0.go
rename to internal/protocols/rtmp/message/msg_command_amf0.go
diff --git a/internal/protocols/rtmp/message/command_amf0_test.go b/internal/protocols/rtmp/message/msg_command_amf0_test.go
similarity index 100%
rename from internal/protocols/rtmp/message/command_amf0_test.go
rename to internal/protocols/rtmp/message/msg_command_amf0_test.go
diff --git a/internal/protocols/rtmp/message/data_amf0.go b/internal/protocols/rtmp/message/msg_data_amf0.go
similarity index 100%
rename from internal/protocols/rtmp/message/data_amf0.go
rename to internal/protocols/rtmp/message/msg_data_amf0.go
diff --git a/internal/protocols/rtmp/message/set_chunk_size.go b/internal/protocols/rtmp/message/msg_set_chunk_size.go
similarity index 100%
rename from internal/protocols/rtmp/message/set_chunk_size.go
rename to internal/protocols/rtmp/message/msg_set_chunk_size.go
diff --git a/internal/protocols/rtmp/message/set_peer_bandwidth.go b/internal/protocols/rtmp/message/msg_set_peer_bandwidth.go
similarity index 100%
rename from internal/protocols/rtmp/message/set_peer_bandwidth.go
rename to internal/protocols/rtmp/message/msg_set_peer_bandwidth.go
diff --git a/internal/protocols/rtmp/message/set_window_ack_size.go b/internal/protocols/rtmp/message/msg_set_window_ack_size.go
similarity index 100%
rename from internal/protocols/rtmp/message/set_window_ack_size.go
rename to internal/protocols/rtmp/message/msg_set_window_ack_size.go
diff --git a/internal/protocols/rtmp/message/user_control_ping_request.go b/internal/protocols/rtmp/message/msg_user_control_ping_request.go
similarity index 100%
rename from internal/protocols/rtmp/message/user_control_ping_request.go
rename to internal/protocols/rtmp/message/msg_user_control_ping_request.go
diff --git a/internal/protocols/rtmp/message/user_control_ping_response.go b/internal/protocols/rtmp/message/msg_user_control_ping_response.go
similarity index 100%
rename from internal/protocols/rtmp/message/user_control_ping_response.go
rename to internal/protocols/rtmp/message/msg_user_control_ping_response.go
diff --git a/internal/protocols/rtmp/message/user_control_set_buffer_length.go b/internal/protocols/rtmp/message/msg_user_control_set_buffer_length.go
similarity index 100%
rename from internal/protocols/rtmp/message/user_control_set_buffer_length.go
rename to internal/protocols/rtmp/message/msg_user_control_set_buffer_length.go
diff --git a/internal/protocols/rtmp/message/user_control_stream_begin.go b/internal/protocols/rtmp/message/msg_user_control_stream_begin.go
similarity index 100%
rename from internal/protocols/rtmp/message/user_control_stream_begin.go
rename to internal/protocols/rtmp/message/msg_user_control_stream_begin.go
diff --git a/internal/protocols/rtmp/message/user_control_stream_dry.go b/internal/protocols/rtmp/message/msg_user_control_stream_dry.go
similarity index 100%
rename from internal/protocols/rtmp/message/user_control_stream_dry.go
rename to internal/protocols/rtmp/message/msg_user_control_stream_dry.go
diff --git a/internal/protocols/rtmp/message/user_control_stream_eof.go b/internal/protocols/rtmp/message/msg_user_control_stream_eof.go
similarity index 100%
rename from internal/protocols/rtmp/message/user_control_stream_eof.go
rename to internal/protocols/rtmp/message/msg_user_control_stream_eof.go
diff --git a/internal/protocols/rtmp/message/user_control_stream_is_recorded.go b/internal/protocols/rtmp/message/msg_user_control_stream_is_recorded.go
similarity index 100%
rename from internal/protocols/rtmp/message/user_control_stream_is_recorded.go
rename to internal/protocols/rtmp/message/msg_user_control_stream_is_recorded.go
diff --git a/internal/protocols/rtmp/message/video.go b/internal/protocols/rtmp/message/msg_video.go
similarity index 100%
rename from internal/protocols/rtmp/message/video.go
rename to internal/protocols/rtmp/message/msg_video.go
diff --git a/internal/protocols/rtmp/message/extended_coded_frames.go b/internal/protocols/rtmp/message/msg_video_ex_coded_frames.go
similarity index 81%
rename from internal/protocols/rtmp/message/extended_coded_frames.go
rename to internal/protocols/rtmp/message/msg_video_ex_coded_frames.go
index 5759f4b8ea21..1e4e071143e1 100644
--- a/internal/protocols/rtmp/message/extended_coded_frames.go
+++ b/internal/protocols/rtmp/message/msg_video_ex_coded_frames.go
@@ -7,8 +7,8 @@ import (
 	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
 )
 
-// ExtendedCodedFrames is a CodedFrames extended message.
-type ExtendedCodedFrames struct {
+// VideoExCodedFrames is a CodedFrames extended message.
+type VideoExCodedFrames struct {
 	ChunkStreamID   byte
 	DTS             time.Duration
 	MessageStreamID uint32
@@ -17,7 +17,7 @@ type ExtendedCodedFrames struct {
 	Payload         []byte
 }
 
-func (m *ExtendedCodedFrames) unmarshal(raw *rawmessage.Message) error {
+func (m *VideoExCodedFrames) unmarshal(raw *rawmessage.Message) error {
 	if len(raw.Body) < 8 {
 		return fmt.Errorf("not enough bytes")
 	}
@@ -37,7 +37,7 @@ func (m *ExtendedCodedFrames) unmarshal(raw *rawmessage.Message) error {
 	return nil
 }
 
-func (m ExtendedCodedFrames) marshalBodySize() int {
+func (m VideoExCodedFrames) marshalBodySize() int {
 	var l int
 	if m.FourCC == FourCCHEVC {
 		l = 8 + len(m.Payload)
@@ -47,10 +47,10 @@ func (m ExtendedCodedFrames) marshalBodySize() int {
 	return l
 }
 
-func (m ExtendedCodedFrames) marshal() (*rawmessage.Message, error) {
+func (m VideoExCodedFrames) marshal() (*rawmessage.Message, error) {
 	body := make([]byte, m.marshalBodySize())
 
-	body[0] = 0b10000000 | byte(ExtendedTypeCodedFrames)
+	body[0] = 0b10000000 | byte(VideoExTypeCodedFrames)
 	body[1] = uint8(m.FourCC >> 24)
 	body[2] = uint8(m.FourCC >> 16)
 	body[3] = uint8(m.FourCC >> 8)
diff --git a/internal/protocols/rtmp/message/extended_frames_x.go b/internal/protocols/rtmp/message/msg_video_ex_frames_x.go
similarity index 75%
rename from internal/protocols/rtmp/message/extended_frames_x.go
rename to internal/protocols/rtmp/message/msg_video_ex_frames_x.go
index a85ea764e3cb..3443c7778e9d 100644
--- a/internal/protocols/rtmp/message/extended_frames_x.go
+++ b/internal/protocols/rtmp/message/msg_video_ex_frames_x.go
@@ -7,8 +7,8 @@ import (
 	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
 )
 
-// ExtendedFramesX is a FramesX extended message.
-type ExtendedFramesX struct {
+// VideoExFramesX is a FramesX extended message.
+type VideoExFramesX struct {
 	ChunkStreamID   byte
 	DTS             time.Duration
 	MessageStreamID uint32
@@ -16,7 +16,7 @@ type ExtendedFramesX struct {
 	Payload         []byte
 }
 
-func (m *ExtendedFramesX) unmarshal(raw *rawmessage.Message) error {
+func (m *VideoExFramesX) unmarshal(raw *rawmessage.Message) error {
 	if len(raw.Body) < 6 {
 		return fmt.Errorf("not enough bytes")
 	}
@@ -30,14 +30,14 @@ func (m *ExtendedFramesX) unmarshal(raw *rawmessage.Message) error {
 	return nil
 }
 
-func (m ExtendedFramesX) marshalBodySize() int {
+func (m VideoExFramesX) marshalBodySize() int {
 	return 5 + len(m.Payload)
 }
 
-func (m ExtendedFramesX) marshal() (*rawmessage.Message, error) {
+func (m VideoExFramesX) marshal() (*rawmessage.Message, error) {
 	body := make([]byte, m.marshalBodySize())
 
-	body[0] = 0b10000000 | byte(ExtendedTypeFramesX)
+	body[0] = 0b10000000 | byte(VideoExTypeFramesX)
 	body[1] = uint8(m.FourCC >> 24)
 	body[2] = uint8(m.FourCC >> 16)
 	body[3] = uint8(m.FourCC >> 8)
diff --git a/internal/protocols/rtmp/message/extended_metadata.go b/internal/protocols/rtmp/message/msg_video_ex_metadata.go
similarity index 79%
rename from internal/protocols/rtmp/message/extended_metadata.go
rename to internal/protocols/rtmp/message/msg_video_ex_metadata.go
index 8a8ee5172c5a..5a79c200ba1c 100644
--- a/internal/protocols/rtmp/message/extended_metadata.go
+++ b/internal/protocols/rtmp/message/msg_video_ex_metadata.go
@@ -8,8 +8,8 @@ import (
 	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
 )
 
-// ExtendedMetadata is a metadata extended message.
-type ExtendedMetadata struct {
+// VideoExMetadata is a metadata extended message.
+type VideoExMetadata struct {
 	ChunkStreamID   byte
 	DTS             time.Duration
 	MessageStreamID uint32
@@ -17,7 +17,7 @@ type ExtendedMetadata struct {
 	Payload         amf0.Data
 }
 
-func (m *ExtendedMetadata) unmarshal(raw *rawmessage.Message) error {
+func (m *VideoExMetadata) unmarshal(raw *rawmessage.Message) error {
 	if len(raw.Body) < 6 {
 		return fmt.Errorf("invalid body size")
 	}
@@ -36,7 +36,7 @@ func (m *ExtendedMetadata) unmarshal(raw *rawmessage.Message) error {
 	return nil
 }
 
-func (m ExtendedMetadata) marshalBodySize() (int, error) {
+func (m VideoExMetadata) marshalBodySize() (int, error) {
 	ms, err := m.Payload.MarshalSize()
 	if err != nil {
 		return 0, err
@@ -44,14 +44,14 @@ func (m ExtendedMetadata) marshalBodySize() (int, error) {
 	return 5 + ms, nil
 }
 
-func (m ExtendedMetadata) marshal() (*rawmessage.Message, error) {
+func (m VideoExMetadata) marshal() (*rawmessage.Message, error) {
 	mbs, err := m.marshalBodySize()
 	if err != nil {
 		return nil, err
 	}
 	body := make([]byte, mbs)
 
-	body[0] = 0b10000000 | byte(ExtendedTypeMetadata)
+	body[0] = 0b10000000 | byte(VideoExTypeMetadata)
 	body[1] = uint8(m.FourCC >> 24)
 	body[2] = uint8(m.FourCC >> 16)
 	body[3] = uint8(m.FourCC >> 8)
diff --git a/internal/protocols/rtmp/message/extended_sequence_end.go b/internal/protocols/rtmp/message/msg_video_ex_sequence_end.go
similarity index 59%
rename from internal/protocols/rtmp/message/extended_sequence_end.go
rename to internal/protocols/rtmp/message/msg_video_ex_sequence_end.go
index b595225d8677..7de3ac550936 100644
--- a/internal/protocols/rtmp/message/extended_sequence_end.go
+++ b/internal/protocols/rtmp/message/msg_video_ex_sequence_end.go
@@ -6,12 +6,12 @@ import (
 	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
 )
 
-// ExtendedSequenceEnd is a sequence end extended message.
-type ExtendedSequenceEnd struct {
+// VideoExSequenceEnd is a sequence end extended message.
+type VideoExSequenceEnd struct {
 	FourCC FourCC
 }
 
-func (m *ExtendedSequenceEnd) unmarshal(raw *rawmessage.Message) error {
+func (m *VideoExSequenceEnd) unmarshal(raw *rawmessage.Message) error {
 	if len(raw.Body) < 5 {
 		return fmt.Errorf("invalid body size")
 	}
@@ -21,6 +21,6 @@ func (m *ExtendedSequenceEnd) unmarshal(raw *rawmessage.Message) error {
 	return nil
 }
 
-func (m ExtendedSequenceEnd) marshal() (*rawmessage.Message, error) {
+func (m VideoExSequenceEnd) marshal() (*rawmessage.Message, error) {
 	return nil, fmt.Errorf("TODO")
 }
diff --git a/internal/protocols/rtmp/message/extended_sequence_start.go b/internal/protocols/rtmp/message/msg_video_ex_sequence_start.go
similarity index 71%
rename from internal/protocols/rtmp/message/extended_sequence_start.go
rename to internal/protocols/rtmp/message/msg_video_ex_sequence_start.go
index 59804c6b6942..afe32f3a4430 100644
--- a/internal/protocols/rtmp/message/extended_sequence_start.go
+++ b/internal/protocols/rtmp/message/msg_video_ex_sequence_start.go
@@ -6,15 +6,15 @@ import (
 	"github.com/bluenviron/mediamtx/internal/protocols/rtmp/rawmessage"
 )
 
-// ExtendedSequenceStart is a sequence start extended message.
-type ExtendedSequenceStart struct {
+// VideoExSequenceStart is a sequence start extended message.
+type VideoExSequenceStart struct {
 	ChunkStreamID   byte
 	MessageStreamID uint32
 	FourCC          FourCC
 	Config          []byte
 }
 
-func (m *ExtendedSequenceStart) unmarshal(raw *rawmessage.Message) error {
+func (m *VideoExSequenceStart) unmarshal(raw *rawmessage.Message) error {
 	if len(raw.Body) < 6 {
 		return fmt.Errorf("not enough bytes")
 	}
@@ -27,14 +27,14 @@ func (m *ExtendedSequenceStart) unmarshal(raw *rawmessage.Message) error {
 	return nil
 }
 
-func (m ExtendedSequenceStart) marshalBodySize() int {
+func (m VideoExSequenceStart) marshalBodySize() int {
 	return 5 + len(m.Config)
 }
 
-func (m ExtendedSequenceStart) marshal() (*rawmessage.Message, error) {
+func (m VideoExSequenceStart) marshal() (*rawmessage.Message, error) {
 	body := make([]byte, m.marshalBodySize())
 
-	body[0] = 0b10000000 | byte(ExtendedTypeSequenceStart)
+	body[0] = 0b10000000 | byte(VideoExTypeSequenceStart)
 	body[1] = uint8(m.FourCC >> 24)
 	body[2] = uint8(m.FourCC >> 16)
 	body[3] = uint8(m.FourCC >> 8)
diff --git a/internal/protocols/rtmp/message/reader.go b/internal/protocols/rtmp/message/reader.go
index b4a34b63adba..3aba9e512fc0 100644
--- a/internal/protocols/rtmp/message/reader.go
+++ b/internal/protocols/rtmp/message/reader.go
@@ -62,6 +62,36 @@ func allocateMessage(raw *rawmessage.Message) (Message, error) {
 		return &DataAMF0{}, nil
 
 	case TypeAudio:
+		if len(raw.Body) < 5 {
+			return nil, fmt.Errorf("not enough bytes")
+		}
+
+		if (raw.Body[0] >> 4) == 9 {
+			fourCC := FourCC(raw.Body[1])<<24 | FourCC(raw.Body[2])<<16 | FourCC(raw.Body[3])<<8 | FourCC(raw.Body[4])
+
+			switch fourCC {
+			case FourCCOpus:
+			default:
+				return nil, fmt.Errorf("invalid fourCC: %v", fourCC)
+			}
+
+			extendedType := AudioExType(raw.Body[0] & 0x0F)
+
+			switch extendedType {
+			case AudioExTypeSequenceStart:
+				return &AudioExSequenceStart{}, nil
+
+			case AudioExTypeMultichannelConfig:
+				return &AudioExMultichannelConfig{}, nil
+
+			case AudioExTypeCodedFrames:
+				return &AudioExCodedFrames{}, nil
+
+			default:
+				return nil, fmt.Errorf("unsupported audio extended type: %v", extendedType)
+			}
+		}
+
 		return &Audio{}, nil
 
 	case TypeVideo:
@@ -78,29 +108,26 @@ func allocateMessage(raw *rawmessage.Message) (Message, error) {
 				return nil, fmt.Errorf("invalid fourCC: %v", fourCC)
 			}
 
-			extendedType := ExtendedType(raw.Body[0] & 0x0F)
+			extendedType := VideoExType(raw.Body[0] & 0x0F)
 
 			switch extendedType {
-			case ExtendedTypeSequenceStart:
-				return &ExtendedSequenceStart{}, nil
-
-			case ExtendedTypeCodedFrames:
-				return &ExtendedCodedFrames{}, nil
+			case VideoExTypeSequenceStart:
+				return &VideoExSequenceStart{}, nil
 
-			case ExtendedTypeSequenceEnd:
-				return &ExtendedSequenceEnd{}, nil
+			case VideoExTypeCodedFrames:
+				return &VideoExCodedFrames{}, nil
 
-			case ExtendedTypeFramesX:
-				return &ExtendedFramesX{}, nil
+			case VideoExTypeSequenceEnd:
+				return &VideoExSequenceEnd{}, nil
 
-			case ExtendedTypeMetadata:
-				return &ExtendedMetadata{}, nil
+			case VideoExTypeFramesX:
+				return &VideoExFramesX{}, nil
 
-			case ExtendedTypeMPEG2TSSequenceStart:
-				return &ExtendedMPEG2TSSequenceStart{}, nil
+			case VideoExTypeMetadata:
+				return &VideoExMetadata{}, nil
 
 			default:
-				return nil, fmt.Errorf("invalid extended type: %v", extendedType)
+				return nil, fmt.Errorf("unsupported video extended type: %v", extendedType)
 			}
 		}
 		return &Video{}, nil
diff --git a/internal/protocols/rtmp/message/reader_test.go b/internal/protocols/rtmp/message/reader_test.go
index b2f8239ddefd..5a86ac90acad 100644
--- a/internal/protocols/rtmp/message/reader_test.go
+++ b/internal/protocols/rtmp/message/reader_test.go
@@ -22,8 +22,8 @@ var readWriterCases = []struct {
 			Value: 45953968,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x3,
-			0x0, 0x0, 0x0, 0x0, 0x2, 0xbd, 0x33, 0xb0,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x03,
+			0x00, 0x00, 0x00, 0x00, 0x02, 0xbd, 0x33, 0xb0,
 		},
 	},
 	{
@@ -39,8 +39,9 @@ var readWriterCases = []struct {
 			Payload:         []byte{0x01, 0x02, 0x03, 0x04},
 		},
 		[]byte{
-			0x7, 0x5b, 0xc3, 0x6e, 0x0, 0x0, 0x5, 0x8, 0x0, 0x45, 0x31, 0xf, 0x2f,
-			0x01, 0x02, 0x03, 0x04,
+			0x07, 0x5b, 0xc3, 0x6e, 0x00, 0x00, 0x05, 0x08,
+			0x00, 0x45, 0x31, 0x0f, 0x2f, 0x01, 0x02, 0x03,
+			0x04,
 		},
 	},
 	{
@@ -57,8 +58,8 @@ var readWriterCases = []struct {
 			Payload:         []byte{0x5A, 0xC0, 0x77, 0x40},
 		},
 		[]byte{
-			0x7, 0x5b, 0xc3, 0x6e, 0x0, 0x0, 0x6, 0x8,
-			0x0, 0x45, 0x31, 0xf, 0xaf, 0x1, 0x5a, 0xc0,
+			0x07, 0x5b, 0xc3, 0x6e, 0x00, 0x00, 0x06, 0x08,
+			0x00, 0x45, 0x31, 0x0f, 0xaf, 0x01, 0x5a, 0xc0,
 			0x77, 0x40,
 		},
 	},
@@ -78,14 +79,14 @@ var readWriterCases = []struct {
 			},
 		},
 		[]byte{
-			0x3, 0x0, 0x0, 0x0, 0x0, 0x0, 0x2f, 0x14,
-			0x0, 0x5, 0x44, 0x9b, 0x2, 0x0, 0xc, 0x69,
+			0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x2f, 0x14,
+			0x00, 0x05, 0x44, 0x9b, 0x02, 0x00, 0x0c, 0x69,
 			0x38, 0x79, 0x79, 0x74, 0x68, 0x72, 0x65, 0x72,
-			0x67, 0x72, 0x65, 0x0, 0x40, 0xeb, 0x91, 0x0,
-			0x0, 0x0, 0x0, 0x0, 0x3, 0x0, 0x2, 0x6b,
-			0x31, 0x2, 0x0, 0x2, 0x76, 0x31, 0x0, 0x2,
-			0x6b, 0x32, 0x2, 0x0, 0x2, 0x76, 0x32, 0x0,
-			0x0, 0x9, 0x5,
+			0x67, 0x72, 0x65, 0x00, 0x40, 0xeb, 0x91, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x02, 0x6b,
+			0x31, 0x02, 0x00, 0x02, 0x76, 0x31, 0x00, 0x02,
+			0x6b, 0x32, 0x02, 0x00, 0x02, 0x76, 0x32, 0x00,
+			0x00, 0x09, 0x05,
 		},
 	},
 	{
@@ -100,9 +101,9 @@ var readWriterCases = []struct {
 			},
 		},
 		[]byte{
-			0x3, 0x0, 0x0, 0x0, 0x0, 0x0, 0x13, 0x12,
-			0x0, 0x5, 0x44, 0x9b, 0x0, 0x40, 0x6d, 0x40,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x6,
+			0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x13, 0x12,
+			0x00, 0x05, 0x44, 0x9b, 0x00, 0x40, 0x6d, 0x40,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x06,
 			0x73, 0x74, 0x72, 0x69, 0x6e, 0x67, 0x05,
 		},
 	},
@@ -112,8 +113,8 @@ var readWriterCases = []struct {
 			Value: 10000,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x1,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x27, 0x10,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x01,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x27, 0x10,
 		},
 	},
 	{
@@ -122,8 +123,8 @@ var readWriterCases = []struct {
 			Value: 10000,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x1,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x27, 0x10,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x01,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x27, 0x10,
 		},
 	},
 	{
@@ -132,8 +133,8 @@ var readWriterCases = []struct {
 			Value: 10000,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x1,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x27, 0x10,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x01,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x27, 0x10,
 		},
 	},
 	{
@@ -142,8 +143,8 @@ var readWriterCases = []struct {
 			ServerTime: 569834435,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x4,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x21, 0xf6,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x04,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x21, 0xf6,
 			0xfb, 0xc3,
 		},
 	},
@@ -153,8 +154,8 @@ var readWriterCases = []struct {
 			ServerTime: 569834435,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x4,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x7, 0x21, 0xf6,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x04,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0x21, 0xf6,
 			0xfb, 0xc3,
 		},
 	},
@@ -165,9 +166,9 @@ var readWriterCases = []struct {
 			BufferLength: 235345,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0xa, 0x4,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x3, 0x0, 0x0,
-			0x8a, 0xce, 0x0, 0x3, 0x97, 0x51,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x04,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00,
+			0x8a, 0xce, 0x00, 0x03, 0x97, 0x51,
 		},
 	},
 	{
@@ -176,8 +177,8 @@ var readWriterCases = []struct {
 			StreamID: 35534,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x4,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x04,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 			0x8a, 0xce,
 		},
 	},
@@ -187,8 +188,8 @@ var readWriterCases = []struct {
 			StreamID: 35534,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x4,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x2, 0x0, 0x0,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x04,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00,
 			0x8a, 0xce,
 		},
 	},
@@ -198,8 +199,8 @@ var readWriterCases = []struct {
 			StreamID: 35534,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x4,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x04,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00,
 			0x8a, 0xce,
 		},
 	},
@@ -209,8 +210,8 @@ var readWriterCases = []struct {
 			StreamID: 35534,
 		},
 		[]byte{
-			0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x6, 0x4,
-			0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x0, 0x0,
+			0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x04,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00,
 			0x8a, 0xce,
 		},
 	},
@@ -234,7 +235,7 @@ var readWriterCases = []struct {
 	},
 	{
 		"extended sequence start",
-		&ExtendedSequenceStart{
+		&VideoExSequenceStart{
 			ChunkStreamID:   4,
 			MessageStreamID: 0x1000000,
 			FourCC:          FourCCHEVC,
@@ -248,7 +249,7 @@ var readWriterCases = []struct {
 	},
 	{
 		"extended coded frames",
-		&ExtendedCodedFrames{
+		&VideoExCodedFrames{
 			ChunkStreamID:   4,
 			DTS:             15100 * time.Millisecond,
 			MessageStreamID: 0x1000000,
@@ -264,7 +265,7 @@ var readWriterCases = []struct {
 	},
 	{
 		"extended frames x",
-		&ExtendedFramesX{
+		&VideoExFramesX{
 			ChunkStreamID:   4,
 			DTS:             15100 * time.Millisecond,
 			MessageStreamID: 0x1000000,
@@ -279,7 +280,7 @@ var readWriterCases = []struct {
 	},
 	{
 		"extended metadata",
-		&ExtendedMetadata{
+		&VideoExMetadata{
 			ChunkStreamID:   0x6,
 			DTS:             0,
 			MessageStreamID: 0x1000000,
diff --git a/internal/protocols/rtmp/reader.go b/internal/protocols/rtmp/reader.go
index b111780b8058..3dfdf2216a26 100644
--- a/internal/protocols/rtmp/reader.go
+++ b/internal/protocols/rtmp/reader.go
@@ -31,6 +31,9 @@ type OnDataVP9Func func(pts time.Duration, frame []byte)
 // OnDataH26xFunc is the prototype of the callback passed to OnDataH26x().
 type OnDataH26xFunc func(pts time.Duration, au [][]byte)
 
+// OnDataOpusFunc is the prototype of the callback passed to OnDataOpus().
+type OnDataOpusFunc func(pts time.Duration, packet []byte)
+
 // OnDataMPEG4AudioFunc is the prototype of the callback passed to OnDataMPEG4Audio().
 type OnDataMPEG4AudioFunc func(pts time.Duration, au []byte)
 
@@ -87,17 +90,12 @@ func hasAudio(md amf0.Object, audioTrack *format.Format) (bool, error) {
 		case 0:
 			return false, nil
 
-		case message.CodecMPEG4Audio, message.CodecLPCM:
-			return true, nil
-
 		case message.CodecMPEG1Audio:
 			*audioTrack = &format.MPEG1Audio{}
 			return true, nil
 
-		case message.CodecPCMA:
-			return true, nil
-
-		case message.CodecPCMU:
+		case message.CodecMPEG4Audio, message.CodecLPCM,
+			message.CodecPCMA, message.CodecPCMU, float64(message.FourCCOpus):
 			return true, nil
 		}
 
@@ -263,7 +261,7 @@ func tracksFromMetadata(conn *Conn, payload []interface{}) (format.Format, forma
 				return videoTrack, nil, nil
 			}
 
-		case *message.ExtendedSequenceStart:
+		case *message.VideoExSequenceStart:
 			if !hasVideo {
 				return nil, nil, fmt.Errorf("unexpected video packet")
 			}
@@ -308,7 +306,7 @@ func tracksFromMetadata(conn *Conn, payload []interface{}) (format.Format, forma
 						PayloadTyp: 96,
 					}
 
-				default: // VP9
+				case message.FourCCVP9:
 					var vpcc mp4.VpcC
 					_, err = mp4.Unmarshal(bytes.NewReader(msg.Config), uint64(len(msg.Config)), &vpcc, mp4.Context{})
 					if err != nil {
@@ -383,6 +381,20 @@ func tracksFromMetadata(conn *Conn, payload []interface{}) (format.Format, forma
 					}
 				}
 			}
+
+		case *message.AudioExSequenceStart:
+			if !hasAudio {
+				return nil, nil, fmt.Errorf("unexpected audio packet")
+			}
+
+			if audioTrack == nil {
+				if msg.FourCC == message.FourCCOpus {
+					audioTrack = &format.Opus{
+						PayloadTyp:   96,
+						ChannelCount: 2, // TODO
+					}
+				}
+			}
 		}
 	}
 }
@@ -467,7 +479,7 @@ type Reader struct {
 	videoTrack  format.Format
 	audioTrack  format.Format
 	onDataVideo func(message.Message) error
-	onDataAudio func(*message.Audio) error
+	onDataAudio func(message.Message) error
 }
 
 // NewReader allocates a Reader.
@@ -542,7 +554,7 @@ func (r *Reader) Tracks() (format.Format, format.Format) {
 // OnDataAV1 sets a callback that is called when AV1 data is received.
 func (r *Reader) OnDataAV1(cb OnDataAV1Func) {
 	r.onDataVideo = func(msg message.Message) error {
-		if msg, ok := msg.(*message.ExtendedCodedFrames); ok {
+		if msg, ok := msg.(*message.VideoExCodedFrames); ok {
 			tu, err := av1.BitstreamUnmarshal(msg.Payload, true)
 			if err != nil {
 				return fmt.Errorf("unable to decode bitstream: %w", err)
@@ -557,7 +569,7 @@ func (r *Reader) OnDataAV1(cb OnDataAV1Func) {
 // OnDataVP9 sets a callback that is called when VP9 data is received.
 func (r *Reader) OnDataVP9(cb OnDataVP9Func) {
 	r.onDataVideo = func(msg message.Message) error {
-		if msg, ok := msg.(*message.ExtendedCodedFrames); ok {
+		if msg, ok := msg.(*message.VideoExCodedFrames); ok {
 			cb(msg.DTS, msg.Payload)
 		}
 		return nil
@@ -579,7 +591,7 @@ func (r *Reader) OnDataH265(cb OnDataH26xFunc) {
 
 			cb(msg.DTS+msg.PTSDelta, au)
 
-		case *message.ExtendedFramesX:
+		case *message.VideoExFramesX:
 			au, err := h264.AVCCUnmarshal(msg.Payload)
 			if err != nil {
 				if errors.Is(err, h264.ErrAVCCNoNALUs) {
@@ -590,7 +602,7 @@ func (r *Reader) OnDataH265(cb OnDataH26xFunc) {
 
 			cb(msg.DTS, au)
 
-		case *message.ExtendedCodedFrames:
+		case *message.VideoExCodedFrames:
 			au, err := h264.AVCCUnmarshal(msg.Payload)
 			if err != nil {
 				if errors.Is(err, h264.ErrAVCCNoNALUs) {
@@ -642,11 +654,23 @@ func (r *Reader) OnDataH264(cb OnDataH26xFunc) {
 	}
 }
 
+// OnDataOpus sets a callback that is called when Opus data is received.
+func (r *Reader) OnDataOpus(cb OnDataOpusFunc) {
+	r.onDataAudio = func(msg message.Message) error {
+		if msg, ok := msg.(*message.AudioExCodedFrames); ok {
+			cb(msg.DTS, msg.Payload)
+		}
+		return nil
+	}
+}
+
 // OnDataMPEG4Audio sets a callback that is called when MPEG-4 Audio data is received.
 func (r *Reader) OnDataMPEG4Audio(cb OnDataMPEG4AudioFunc) {
-	r.onDataAudio = func(msg *message.Audio) error {
-		if msg.AACType == message.AudioAACTypeAU {
-			cb(msg.DTS, msg.Payload)
+	r.onDataAudio = func(msg message.Message) error {
+		if msg, ok := msg.(*message.Audio); ok {
+			if msg.AACType == message.AudioAACTypeAU {
+				cb(msg.DTS, msg.Payload)
+			}
 		}
 		return nil
 	}
@@ -654,16 +678,20 @@ func (r *Reader) OnDataMPEG4Audio(cb OnDataMPEG4AudioFunc) {
 
 // OnDataMPEG1Audio sets a callback that is called when MPEG-1 Audio data is received.
 func (r *Reader) OnDataMPEG1Audio(cb OnDataMPEG1AudioFunc) {
-	r.onDataAudio = func(msg *message.Audio) error {
-		cb(msg.DTS, msg.Payload)
+	r.onDataAudio = func(msg message.Message) error {
+		if msg, ok := msg.(*message.Audio); ok {
+			cb(msg.DTS, msg.Payload)
+		}
 		return nil
 	}
 }
 
 // OnDataG711 sets a callback that is called when G711 data is received.
 func (r *Reader) OnDataG711(cb OnDataG711Func) {
-	r.onDataAudio = func(msg *message.Audio) error {
-		cb(msg.DTS, msg.Payload)
+	r.onDataAudio = func(msg message.Message) error {
+		if msg, ok := msg.(*message.Audio); ok {
+			cb(msg.DTS, msg.Payload)
+		}
 		return nil
 	}
 }
@@ -673,23 +701,27 @@ func (r *Reader) OnDataLPCM(cb OnDataLPCMFunc) {
 	bitDepth := r.audioTrack.(*format.LPCM).BitDepth
 
 	if bitDepth == 16 {
-		r.onDataAudio = func(msg *message.Audio) error {
-			le := len(msg.Payload)
-			if le%2 != 0 {
-				return fmt.Errorf("invalid payload length: %d", le)
-			}
+		r.onDataAudio = func(msg message.Message) error {
+			if msg, ok := msg.(*message.Audio); ok {
+				le := len(msg.Payload)
+				if le%2 != 0 {
+					return fmt.Errorf("invalid payload length: %d", le)
+				}
 
-			// convert from little endian to big endian
-			for i := 0; i < le; i += 2 {
-				msg.Payload[i], msg.Payload[i+1] = msg.Payload[i+1], msg.Payload[i]
-			}
+				// convert from little endian to big endian
+				for i := 0; i < le; i += 2 {
+					msg.Payload[i], msg.Payload[i+1] = msg.Payload[i+1], msg.Payload[i]
+				}
 
-			cb(msg.DTS, msg.Payload)
+				cb(msg.DTS, msg.Payload)
+			}
 			return nil
 		}
 	} else {
-		r.onDataAudio = func(msg *message.Audio) error {
-			cb(msg.DTS, msg.Payload)
+		r.onDataAudio = func(msg message.Message) error {
+			if msg, ok := msg.(*message.Audio); ok {
+				cb(msg.DTS, msg.Payload)
+			}
 			return nil
 		}
 	}
@@ -703,14 +735,14 @@ func (r *Reader) Read() error {
 	}
 
 	switch msg := msg.(type) {
-	case *message.Video, *message.ExtendedFramesX, *message.ExtendedCodedFrames:
+	case *message.Video, *message.VideoExFramesX, *message.VideoExCodedFrames:
 		if r.onDataVideo == nil {
 			return fmt.Errorf("received a video packet, but track is not set up")
 		}
 
 		return r.onDataVideo(msg)
 
-	case *message.Audio:
+	case *message.Audio, *message.AudioExCodedFrames:
 		if r.onDataAudio == nil {
 			return fmt.Errorf("received an audio packet, but track is not set up")
 		}
diff --git a/internal/protocols/rtmp/reader_test.go b/internal/protocols/rtmp/reader_test.go
index f5a2e9a5c5d8..655fecb21c49 100644
--- a/internal/protocols/rtmp/reader_test.go
+++ b/internal/protocols/rtmp/reader_test.go
@@ -579,7 +579,7 @@ func TestReadTracks(t *testing.T) {
 						},
 					},
 				},
-				&message.ExtendedSequenceStart{
+				&message.VideoExSequenceStart{
 					ChunkStreamID:   4,
 					MessageStreamID: 0x1000000,
 					FourCC:          message.FourCCHEVC,
@@ -628,7 +628,7 @@ func TestReadTracks(t *testing.T) {
 						},
 					},
 				},
-				&message.ExtendedSequenceStart{
+				&message.VideoExSequenceStart{
 					ChunkStreamID:   4,
 					MessageStreamID: 0x1000000,
 					FourCC:          message.FourCCHEVC,
@@ -690,7 +690,7 @@ func TestReadTracks(t *testing.T) {
 						},
 					},
 				},
-				&message.ExtendedSequenceStart{
+				&message.VideoExSequenceStart{
 					ChunkStreamID:   6,
 					MessageStreamID: 0x1000000,
 					FourCC:          message.FourCCAV1,
diff --git a/internal/protocols/rtmp/to_stream.go b/internal/protocols/rtmp/to_stream.go
index 4b8f8b0ce930..0a5e956bc794 100644
--- a/internal/protocols/rtmp/to_stream.go
+++ b/internal/protocols/rtmp/to_stream.go
@@ -95,6 +95,17 @@ func ToStream(r *Reader, stream **stream.Stream) ([]*description.Media, error) {
 		medias = append(medias, medi)
 
 		switch audioFormat.(type) {
+		case *format.Opus:
+			r.OnDataOpus(func(pts time.Duration, packet []byte) {
+				(*stream).WriteUnit(medi, audioFormat, &unit.Opus{
+					Base: unit.Base{
+						NTP: time.Now(),
+						PTS: durationToTimestamp(pts, audioFormat.ClockRate()),
+					},
+					Packets: [][]byte{packet},
+				})
+			})
+
 		case *format.MPEG4Audio:
 			r.OnDataMPEG4Audio(func(pts time.Duration, au []byte) {
 				(*stream).WriteUnit(medi, audioFormat, &unit.MPEG4Audio{