diff --git a/av/codec/frame.go b/av/codec/frame.go
index 144d133..5943d37 100644
--- a/av/codec/frame.go
+++ b/av/codec/frame.go
@@ -4,15 +4,77 @@
 
 package codec
 
-// 帧类型
-const (
-	FrameVideo = byte(iota)
-	FrameAudio
+import (
+	"fmt"
+	"strings"
 )
 
+// MediaType 媒体类型
+type MediaType int
+
+// 媒体类型常量
+const (
+	MediaTypeUnknown MediaType = iota - 1 // Usually treated as MediaTypeData
+	MediaTypeVideo
+	MediaTypeAudio
+	MediaTypeData // Opaque data information usually continuous
+	MediaTypeSubtitle
+	MediaTypeAttachment // Opaque data information usually sparse
+	MediaTypeNB
+)
+
+// String returns a lower-case ASCII representation of the media type.
+func (mt MediaType) String() string {
+	switch mt {
+	case MediaTypeVideo:
+		return "video"
+	case MediaTypeAudio:
+		return "audio"
+	case MediaTypeData:
+		return "data"
+	case MediaTypeSubtitle:
+		return "subtitle"
+	case MediaTypeAttachment:
+		return "attachment"
+	default:
+		return ""
+	}
+}
+
+// MarshalText marshals the MediaType to text.
+func (mt *MediaType) MarshalText() ([]byte, error) {
+	return []byte(mt.String()), nil
+}
+
+// UnmarshalText unmarshals text to a MediaType.
+func (mt *MediaType) UnmarshalText(text []byte) error {
+	if !mt.unmarshalText(string(text)) {
+		return fmt.Errorf("unrecognized media type: %q", text)
+	}
+	return nil
+}
+
+func (mt *MediaType) unmarshalText(text string) bool {
+	switch strings.ToLower(text) {
+	case "video":
+		*mt = MediaTypeVideo
+	case "audio":
+		*mt = MediaTypeAudio
+	case "data":
+		*mt = MediaTypeData
+	case "subtitle":
+		*mt = MediaTypeSubtitle
+	case "attachment":
+		*mt = MediaTypeAttachment
+	default:
+		return false
+	}
+	return true
+}
+
 // Frame 音视频完整帧
 type Frame struct {
-	FrameType    byte   // 帧类型
+	MediaType           // 媒体类型
 	AbsTimestamp int64  // 绝对时间戳(主要用于表示 pts)，单位为 ms 的 UNIX 时间
 	Payload      []byte // 媒体数据载荷
 }
diff --git a/av/codec/metadata.go b/av/codec/metadata.go
index 04a199d..d9e3f6b 100644
--- a/av/codec/metadata.go
+++ b/av/codec/metadata.go
@@ -6,14 +6,16 @@ package codec
 
 // VideoMeta 视频元数据
 type VideoMeta struct {
-	Codec     string  `json:"codec"`
-	Width     int     `json:"width,omitempty"`
-	Height    int     `json:"height,omitempty"`
-	FrameRate float64 `json:"framerate,omitempty"`
-	DataRate  float64 `json:"datarate,omitempty"`
-	Sps       []byte  `json:"-"`
-	Pps       []byte  `json:"-"`
-	Vps       []byte  `json:"-"`
+	Codec          string  `json:"codec"`
+	Width          int     `json:"width,omitempty"`
+	Height         int     `json:"height,omitempty"`
+	FixedFrameRate bool    `json:"fixedframerate,omitempty"`
+	FrameRate      float64 `json:"framerate,omitempty"`
+	DataRate       float64 `json:"datarate,omitempty"`
+	ClockRate      int     `json:"clockrate,omitempty"`
+	Sps            []byte  `json:"-"`
+	Pps            []byte  `json:"-"`
+	Vps            []byte  `json:"-"`
 }
 
 // AudioMeta 音频元数据
diff --git a/av/format/flv/muxeravcaac.go b/av/format/flv/muxeravcaac.go
index 47a6bf9..885ff9a 100644
--- a/av/format/flv/muxeravcaac.go
+++ b/av/format/flv/muxeravcaac.go
@@ -116,7 +116,7 @@ func (muxer *MuxerAvcAac) process() {
 			muxer.basePts = frame.AbsTimestamp
 		}
 
-		if frame.FrameType == codec.FrameVideo {
+		if frame.MediaType == codec.MediaTypeVideo {
 			if err := muxer.muxVideoTag(frame); err != nil {
 				muxer.logger.Errorf("flvmuxer: muxVideoTag error - %s", err.Error())
 			}
diff --git a/av/format/mpegts/muxeravcaac.go b/av/format/mpegts/muxeravcaac.go
index 0bf8d86..8019b32 100644
--- a/av/format/mpegts/muxeravcaac.go
+++ b/av/format/mpegts/muxeravcaac.go
@@ -131,7 +131,7 @@ func (muxer *MuxerAvcAac) process() {
 			muxer.basePts = frame.AbsTimestamp
 		}
 
-		if frame.FrameType == codec.FrameVideo {
+		if frame.MediaType == codec.MediaTypeVideo {
 			if err := muxer.muxVideoTag(frame); err != nil {
 				muxer.logger.Errorf("tsmuxer: muxVideoFrame error - %s", err.Error())
 			}
diff --git a/av/format/rtp/aac_depacketizer.go b/av/format/rtp/aac_depacketizer.go
index eecef99..20b1559 100644
--- a/av/format/rtp/aac_depacketizer.go
+++ b/av/format/rtp/aac_depacketizer.go
@@ -75,7 +75,7 @@ func (aacdp *aacDepacketizer) depacketizeFor2ByteAUHeader(packet *Packet) (err e
 		auHeader := uint16(0) | (uint16(auHeaders[0]) << 8) | uint16(auHeaders[1])
 		frameSize := auHeader >> aacdp.indexLength
 		frame := &codec.Frame{
-			FrameType:    codec.FrameAudio,
+			MediaType:    codec.MediaTypeAudio,
 			AbsTimestamp: aacdp.rtp2ntp(frameTimeStamp),
 			Payload:      framesPayload[:frameSize],
 		}
@@ -109,7 +109,7 @@ func (aacdp *aacDepacketizer) depacketizeFor1ByteAUHeader(packet *Packet) (err e
 		auHeader := auHeaders[0]
 		frameSize := auHeader >> aacdp.indexLength
 		frame := &codec.Frame{
-			FrameType:    codec.FrameAudio,
+			MediaType:    codec.MediaTypeAudio,
 			AbsTimestamp: aacdp.rtp2ntp(frameTimeStamp),
 			Payload:      framesPayload[:frameSize],
 		}
diff --git a/av/format/rtp/demuxer_test.go b/av/format/rtp/demuxer_test.go
index d168c55..7048684 100644
--- a/av/format/rtp/demuxer_test.go
+++ b/av/format/rtp/demuxer_test.go
@@ -77,7 +77,7 @@ type frameWriter struct {
 }
 
 func (fw *frameWriter) WriteFrame(frame *codec.Frame) (err error) {
-	if frame.FrameType == codec.FrameVideo {
+	if frame.MediaType == codec.MediaTypeVideo {
 		fw.videoFrames++
 		if h264.IsSps(frame.Payload[0]) {
 			fw.sps++
diff --git a/av/format/rtp/h264_depacketizer.go b/av/format/rtp/h264_depacketizer.go
index 83d455e..f0e7242 100644
--- a/av/format/rtp/h264_depacketizer.go
+++ b/av/format/rtp/h264_depacketizer.go
@@ -67,7 +67,7 @@ func (h264dp *h264Depacketizer) Depacketize(packet *Packet) (err error) {
 			return
 		}
 		frame := &codec.Frame{
-			FrameType:    codec.FrameVideo,
+			MediaType:    codec.MediaTypeVideo,
 			AbsTimestamp: h264dp.rtp2ntp(packet.Timestamp),
 			Payload:      payload,
 		}
@@ -113,7 +113,7 @@ func (h264dp *h264Depacketizer) depacketizeStapa(packet *Packet) (err error) {
 		off += 2
 		if payload[off]&0x1f != h264.NalFillerData {
 			frame := &codec.Frame{
-				FrameType:    codec.FrameVideo,
+				MediaType:    codec.MediaTypeVideo,
 				AbsTimestamp: h264dp.rtp2ntp(packet.Timestamp),
 				Payload:      make([]byte, nalSize),
 			}
@@ -176,7 +176,7 @@ func (h264dp *h264Depacketizer) depacketizeFuA(packet *Packet) (err error) {
 		}
 
 		frame := &codec.Frame{
-			FrameType:    codec.FrameVideo,
+			MediaType:    codec.MediaTypeVideo,
 			AbsTimestamp: h264dp.rtp2ntp(packet.Timestamp),
 			Payload:      make([]byte, frameLen)}