diff --git a/codecParam.go b/codecParam.go
index e05df5f..d6910d1 100644
--- a/codecParam.go
+++ b/codecParam.go
@@ -23,23 +23,30 @@ func (cp *CodecParameters) Free() {
 	C.avcodec_parameters_free(&cp.avCodecParameters)
 }
 
-func (cp *CodecParameters) GetCodecType() int {
+func (cp *CodecParameters) CodecType() int {
 	return int(cp.avCodecParameters.codec_type)
 }
 
-func (cp *CodecParameters) GetCodecId() int {
+func (cp *CodecParameters) CodecId() int {
 	return int(cp.avCodecParameters.codec_id)
 }
 
-func (cp *CodecParameters) GetBitRate() int64 {
+func (cp *CodecParameters) BitRate() int64 {
 	return int64(cp.avCodecParameters.bit_rate)
 }
 
-func (cp *CodecParameters) GetWidth() int {
+func (cp *CodecParameters) Width() int {
 	return int(cp.avCodecParameters.width)
 }
 
-func (cp *CodecParameters) GetHeight() int {
+// Format
+// video: the pixel format, the value corresponds to enum AVPixelFormat.
+// audio: the sample format, the value corresponds to enum AVSampleFormat.
+func (cp *CodecParameters) Format() int32 {
+	return int32(cp.avCodecParameters.format)
+}
+
+func (cp *CodecParameters) Height() int {
 	return int(cp.avCodecParameters.height)
 }
 
diff --git a/example_encoding_test.go b/example_encoding_test.go
new file mode 100644
index 0000000..82c2a22
--- /dev/null
+++ b/example_encoding_test.go
@@ -0,0 +1,96 @@
+package gmf_test
+
+import (
+	"errors"
+	"fmt"
+	"log"
+
+	"github.com/3d0c/gmf"
+)
+
+func Example() {
+	outputfilename := "examples/sample-encoding1.mpg"
+	dstWidth, dstHeight := 640, 480
+
+	codec, err := gmf.FindEncoder(gmf.AV_CODEC_ID_MPEG1VIDEO)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	videoEncCtx := gmf.NewCodecCtx(codec)
+	if videoEncCtx == nil {
+		log.Fatal(errors.New("failed to create a new codec context"))
+	}
+	defer videoEncCtx.Free()
+
+	outputCtx, err := gmf.NewOutputCtx(outputfilename)
+	if err != nil {
+		log.Fatal(errors.New("failed to create a new output context"))
+	}
+	defer outputCtx.Free()
+
+	videoEncCtx.
+		SetBitRate(400000).
+		SetWidth(dstWidth).
+		SetHeight(dstHeight).
+		SetTimeBase(gmf.AVR{Num: 1, Den: 25}).
+		SetPixFmt(gmf.AV_PIX_FMT_YUV420P).
+		SetProfile(gmf.FF_PROFILE_MPEG4_SIMPLE).
+		SetMbDecision(gmf.FF_MB_DECISION_RD)
+
+	if outputCtx.IsGlobalHeader() {
+		videoEncCtx.SetFlag(gmf.CODEC_FLAG_GLOBAL_HEADER)
+	}
+
+	videoStream := outputCtx.NewStream(codec)
+	if videoStream == nil {
+		log.Fatal(errors.New(fmt.Sprintf("Unable to create stream for videoEnc [%s]\n", codec.LongName())))
+	}
+	defer videoStream.Free()
+
+	if err = videoEncCtx.Open(nil); err != nil {
+		log.Fatal(err)
+	}
+	videoStream.DumpContexCodec(videoEncCtx)
+	// videoStream.SetCodecCtx(videoEncCtx)
+
+	outputCtx.SetStartTime(0)
+
+	if err = outputCtx.WriteHeader(); err != nil {
+		log.Fatal(err)
+	}
+	outputCtx.Dump()
+	i := int64(0)
+	n := 0
+
+	for frame := range gmf.GenSyntVideoNewFrame(videoEncCtx.Width(), videoEncCtx.Height(), videoEncCtx.PixFmt()) {
+		frame.SetPts(i)
+
+		if p, err := frame.Encode(videoEncCtx); p != nil {
+			if p.Pts() != gmf.AV_NOPTS_VALUE {
+				p.SetPts(gmf.RescaleQ(p.Pts(), videoEncCtx.TimeBase(), videoStream.TimeBase()))
+			}
+
+			if p.Dts() != gmf.AV_NOPTS_VALUE {
+				p.SetDts(gmf.RescaleQ(p.Dts(), videoEncCtx.TimeBase(), videoStream.TimeBase()))
+			}
+
+			if err := outputCtx.WritePacket(p); err != nil {
+				log.Fatal(err)
+			}
+
+			n++
+
+			log.Printf("Write frame=%d size=%v pts=%v dts=%v\n", frame.Pts(), p.Size(), p.Pts(), p.Dts())
+
+			p.Free()
+		} else if err != nil {
+			log.Fatal(err)
+		}
+
+		frame.Free()
+		i++
+	}
+	fmt.Println("frames written to examples/sample-encoding1.mpg")
+	// Output: frames written to examples/sample-encoding1.mpg
+}
diff --git a/packet_go112.go b/packet_go112.go
index 96c38d4..7a0f52c 100644
--- a/packet_go112.go
+++ b/packet_go112.go
@@ -23,7 +23,7 @@ import (
 )
 
 const (
-	AV_PKT_FLAG_KEY = C.AV_PKT_FLAG_KEY
+	AV_PKT_FLAG_KEY = C.AV_PKT_FLAG_KEY // The packet contains a keyframe
 )
 
 type Packet struct {
diff --git a/packet_test.go b/packet_test.go
index bdda880..3909aed 100644
--- a/packet_test.go
+++ b/packet_test.go
@@ -1,8 +1,9 @@
 package gmf_test
 
 import (
-	"github.com/3d0c/gmf"
 	"testing"
+
+	"github.com/3d0c/gmf"
 )
 
 func TestFramesIterator(t *testing.T) {
@@ -14,9 +15,8 @@ func TestFramesIterator(t *testing.T) {
 
 	cnt := 0
 	ist := assert(inputCtx.GetStream(0)).(*gmf.Stream)
-	t.Log("NbFrames", ist.NbFrames())
-	ctx := ist.CodecCtx()
-	for frame := range gmf.GenSyntVideoNewFrame(ctx.Width(), ctx.Height(), ctx.PixFmt()) {
+	par := ist.CodecPar()
+	for frame := range gmf.GenSyntVideoNewFrame(par.Width(), par.Height(), par.Format()) {
 		cnt++
 		frame.Free()
 	}
@@ -25,3 +25,16 @@ func TestFramesIterator(t *testing.T) {
 		t.Fatalf("Expected %d frames, obtained %d\n", 25, cnt)
 	}
 }
+
+func ExamplePacket_SetData() {
+	p := gmf.NewPacket()
+	defer p.Free()
+	p.SetData([]byte{0x00, 0x00, 0x00, 0x01, 0x67})
+	defer p.FreeData()
+}
+
+func ExamplePacket_SetFlags() {
+	p := gmf.NewPacket()
+	p.SetFlags(p.Flags() | gmf.AV_PKT_FLAG_KEY)
+	defer p.Free()
+}
diff --git a/stream.go b/stream.go
index 2ac4a26..9492a40 100644
--- a/stream.go
+++ b/stream.go
@@ -19,8 +19,9 @@ type Stream struct {
 	SwsCtx   *SwsCtx
 	SwrCtx   *SwrCtx
 	AvFifo   *AVAudioFifo
-	cc       *CodecCtx
-	Pts      int64
+	// Deprecated: Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
+	cc  *CodecCtx
+	Pts int64
 	CgoMemoryManage
 }
 
@@ -47,6 +48,8 @@ func (s *Stream) SetCodecFlags() {
 	s.avStream.codec.flags |= C.AV_CODEC_FLAG_GLOBAL_HEADER
 }
 
+// CodecCtx
+// Deprecated: Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
 func (s *Stream) CodecCtx() *CodecCtx {
 	// Supposed that output context is set and opened by user
 	if s.IsCodecCtxSet() {
@@ -83,7 +86,16 @@ func (s *Stream) SetCodecCtx(cc *CodecCtx) {
 	s.cc = cc
 }
 
-func (s *Stream) SetCodecParameters(cp *CodecParameters) error {
+func (s *Stream) CodecPar() *CodecParameters {
+	if s.avStream == nil || s.avStream.codecpar == nil {
+		return nil
+	}
+	return &CodecParameters{
+		avCodecParameters: s.avStream.codecpar,
+	}
+}
+
+func (s *Stream) SetCodecPar(cp *CodecParameters) error {
 	if cp == nil || cp.avCodecParameters == nil {
 		return fmt.Errorf("codec parameters are not initialized")
 	}
@@ -92,6 +104,8 @@ func (s *Stream) SetCodecParameters(cp *CodecParameters) error {
 	return nil
 }
 
+// IsCodecCtxSet
+// Deprecated: Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
 func (s *Stream) IsCodecCtxSet() bool {
 	return s.cc != nil
 }
@@ -117,7 +131,7 @@ func (s *Stream) TimeBase() AVRational {
 }
 
 func (s *Stream) Type() int32 {
-	return s.CodecCtx().Type()
+	return int32(s.CodecPar().CodecType())
 }
 
 func (s *Stream) IsAudio() bool {
diff --git a/stream_test.go b/stream_test.go
index d853dcb..b6e30fd 100644
--- a/stream_test.go
+++ b/stream_test.go
@@ -1,9 +1,10 @@
 package gmf_test
 
 import (
-	"github.com/3d0c/gmf"
 	"log"
 	"testing"
+
+	"github.com/3d0c/gmf"
 )
 
 func TestStream(t *testing.T) {
@@ -34,9 +35,9 @@ func TestStream(t *testing.T) {
 
 	st := assert(ctx.GetStream(0)).(*gmf.Stream)
 
-	st.SetCodecCtx(cc)
+	st.DumpContexCodec(cc)
 
-	if st.CodecCtx().Height() != td.height || st.CodecCtx().Width() != td.width {
+	if cc.Height() != td.height || cc.Width() != td.width {
 		t.Fatalf("Expected dimension = %dx%d, %dx%d got\n", td.width, td.height, st.CodecCtx().Width(), st.CodecCtx().Height())
 	}
 
@@ -53,7 +54,7 @@ func TestStreamInputCtx(t *testing.T) {
 
 	ist := assert(inputCtx.GetStream(0)).(*gmf.Stream)
 
-	if ist.CodecCtx().Width() != inputSampleWidth || ist.CodecCtx().Height() != inputSampleHeight {
+	if ist.CodecPar().Width() != inputSampleWidth || ist.CodecPar().Height() != inputSampleHeight {
 		t.Fatalf("Expected dimension = %dx%d, %dx%d got\n", inputSampleWidth, inputSampleHeight, ist.CodecCtx().Width(), ist.CodecCtx().Height())
 	}
 
diff --git a/sws_test.go b/sws_test.go
index 18a7774..5ef6360 100644
--- a/sws_test.go
+++ b/sws_test.go
@@ -1,9 +1,10 @@
 package gmf_test
 
 import (
-	"github.com/3d0c/gmf"
 	"log"
 	"testing"
+
+	"github.com/3d0c/gmf"
 )
 
 // @todo export rescaled frame as jpeg and compare dimension.
@@ -45,7 +46,7 @@ func TestScale(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	videoStream.SetCodecCtx(dstCodecCtx)
+	videoStream.DumpContexCodec(dstCodecCtx)
 	swsCtx, err := gmf.NewSwsCtx(srcEncCtx.Width(), srcEncCtx.Height(), srcEncCtx.PixFmt(), dstCodecCtx.Width(), dstCodecCtx.Height(), dstCodecCtx.PixFmt(), gmf.SWS_BICUBIC)
 	if err != nil {
 		t.Fatal(err)