diff --git a/encoders/dv8-enc.go b/encoders/dv8-enc.go
index 3c54622..3395e97 100644
--- a/encoders/dv8-enc.go
+++ b/encoders/dv8-enc.go
@@ -14,10 +14,14 @@ type VP8ImageEncoder struct {
 	FFMpegBinPath string
 	input         io.WriteCloser
 	closed        bool
+	Framerate     int
 }
 
 func (enc *VP8ImageEncoder) Init(videoFileName string) {
 	fileExt := ".webm"
+	if enc.Framerate == 0 {
+		enc.Framerate = 12
+	}
 	if !strings.HasSuffix(videoFileName, fileExt) {
 		videoFileName = videoFileName + fileExt
 	}
diff --git a/encoders/dv9-enc.go b/encoders/dv9-enc.go
index c608789..c5e4016 100644
--- a/encoders/dv9-enc.go
+++ b/encoders/dv9-enc.go
@@ -13,10 +13,14 @@ type DV9ImageEncoder struct {
 	cmd           *exec.Cmd
 	FFMpegBinPath string
 	input         io.WriteCloser
+	Framerate     int
 }
 
 func (enc *DV9ImageEncoder) Init(videoFileName string) {
 	fileExt := ".mp4"
+	if enc.Framerate == 0 {
+		enc.Framerate = 12
+	}
 	if !strings.HasSuffix(videoFileName, fileExt) {
 		videoFileName = videoFileName + fileExt
 	}
diff --git a/encoders/huffyuv-enc.go b/encoders/huffyuv-enc.go
new file mode 100644
index 0000000..8ec3651
--- /dev/null
+++ b/encoders/huffyuv-enc.go
@@ -0,0 +1,116 @@
+package encoders
+
+import (
+	"errors"
+	"image"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+	"vnc2video/logger"
+)
+
+// this is a very common loseless encoder (but produces huge files)
+type HuffYuvImageEncoder struct {
+	FFMpegBinPath string
+	cmd           *exec.Cmd
+	input         io.WriteCloser
+	closed        bool
+	Framerate     int
+}
+
+func (enc *HuffYuvImageEncoder) Init(videoFileName string) {
+	if enc.Framerate == 0 {
+		enc.Framerate = 12
+	}
+
+	fileExt := ".avi"
+	if !strings.HasSuffix(videoFileName, fileExt) {
+		videoFileName = videoFileName + fileExt
+	}
+	//binary := "./ffmpeg"
+	cmd := exec.Command(enc.FFMpegBinPath,
+		"-f", "image2pipe",
+		"-vcodec", "ppm",
+		//"-r", strconv.Itoa(framerate),
+		"-r", "12",
+
+		//"-re",
+		//"-i", "pipe:0",
+		"-an", //no audio
+		//"-vsync", "2",
+		///"-probesize", "10000000",
+		"-y",
+
+		"-i", "-",
+		//"–s", "640×360",
+		"-vcodec", "huffyuv", //"libvpx",//"libvpx-vp9"//"libx264"
+		//"-b:v", "0.33M",
+		"-threads", "7",
+		///"-coder", "1",
+		///"-bf", "0",
+		///"-me_method", "hex",
+		//"-speed", "0",
+		//"-lossless", "1", //for vpx
+		// "-an", "-f", "webm",
+		"-preset", "veryfast",
+		//"-tune", "animation",
+		"-maxrate", "0.5M",
+		"-bufsize", "50M",
+		"-g", "250",
+
+		//"-crf", "0", //for lossless encoding!!!!
+
+		//"-rc_lookahead", "16",
+		//"-profile", "0",
+		"-crf", "34",
+		//"-qmax", "51",
+		//"-qmin", "7",
+		//"-slices", "4",
+		//"-vb", "2M",
+
+		videoFileName,
+	)
+	//cmd := exec.Command("/bin/echo")
+
+	//io.Copy(cmd.Stdout, os.Stdout)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	encInput, err := cmd.StdinPipe()
+	enc.input = encInput
+	if err != nil {
+		logger.Error("can't get ffmpeg input pipe")
+	}
+	enc.cmd = cmd
+}
+func (enc *HuffYuvImageEncoder) Run(videoFileName string) error {
+	if _, err := os.Stat(enc.FFMpegBinPath); os.IsNotExist(err) {
+		logger.Error("encoder file doesn't exist in path:", enc.FFMpegBinPath)
+		return errors.New("encoder file doesn't exist in path" + videoFileName)
+	}
+
+	enc.Init(videoFileName)
+	logger.Debugf("launching binary: %v", enc.cmd)
+	err := enc.cmd.Run()
+	if err != nil {
+		logger.Errorf("error while launching ffmpeg: %v\n err: %v", enc.cmd.Args, err)
+		return err
+	}
+	return nil
+}
+func (enc *HuffYuvImageEncoder) Encode(img image.Image) {
+	if enc.input == nil || enc.closed {
+		return
+	}
+
+	err := encodePPM(enc.input, img)
+	if err != nil {
+		logger.Error("error while encoding image:", err)
+	}
+}
+
+func (enc *HuffYuvImageEncoder) Close() {
+	enc.closed = true
+	//enc.cmd.Process.Kill()
+}
diff --git a/encoders/mjpeg-enc.go b/encoders/mjpeg-enc.go
index ea6fdfd..595d58e 100644
--- a/encoders/mjpeg-enc.go
+++ b/encoders/mjpeg-enc.go
@@ -19,6 +19,9 @@ type MJPegImageEncoder struct {
 
 func (enc *MJPegImageEncoder) Init(videoFileName string) {
 	fileExt := ".avi"
+	if enc.Framerate == 0 {
+		enc.Framerate = 12
+	}
 	if !strings.HasSuffix(videoFileName, fileExt) {
 		videoFileName = videoFileName + fileExt
 	}
diff --git a/encoders/qtrle-enc.go b/encoders/qtrle-enc.go
new file mode 100644
index 0000000..476eb39
--- /dev/null
+++ b/encoders/qtrle-enc.go
@@ -0,0 +1,115 @@
+package encoders
+
+import (
+	"errors"
+	"image"
+	"io"
+	"os"
+	"os/exec"
+	"strings"
+	"vnc2video/logger"
+)
+
+// QTRLEImageEncoder quick time rle is an efficient loseless codec, uses .mov extension
+type QTRLEImageEncoder struct {
+	FFMpegBinPath string
+	cmd           *exec.Cmd
+	input         io.WriteCloser
+	closed        bool
+	Framerate     int
+}
+
+func (enc *QTRLEImageEncoder) Init(videoFileName string) {
+	fileExt := ".mov"
+	if enc.Framerate == 0 {
+		enc.Framerate = 12
+	}
+	if !strings.HasSuffix(videoFileName, fileExt) {
+		videoFileName = videoFileName + fileExt
+	}
+	//binary := "./ffmpeg"
+	cmd := exec.Command(enc.FFMpegBinPath,
+		"-f", "image2pipe",
+		"-vcodec", "ppm",
+		//"-r", strconv.Itoa(framerate),
+		"-r", "12",
+
+		//"-re",
+		//"-i", "pipe:0",
+		"-an", //no audio
+		//"-vsync", "2",
+		///"-probesize", "10000000",
+		"-y",
+
+		"-i", "-",
+		//"–s", "640×360",
+		"-vcodec", "qtrle", //"libvpx",//"libvpx-vp9"//"libx264"
+		//"-b:v", "0.33M",
+		"-threads", "7",
+		///"-coder", "1",
+		///"-bf", "0",
+		///"-me_method", "hex",
+		//"-speed", "0",
+		//"-lossless", "1", //for vpx
+		// "-an", "-f", "webm",
+		"-preset", "veryfast",
+		//"-tune", "animation",
+		"-maxrate", "0.5M",
+		"-bufsize", "50M",
+		"-g", "250",
+
+		//"-crf", "0", //for lossless encoding!!!!
+
+		//"-rc_lookahead", "16",
+		//"-profile", "0",
+		"-crf", "34",
+		//"-qmax", "51",
+		//"-qmin", "7",
+		//"-slices", "4",
+		//"-vb", "2M",
+
+		videoFileName,
+	)
+	//cmd := exec.Command("/bin/echo")
+
+	//io.Copy(cmd.Stdout, os.Stdout)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	encInput, err := cmd.StdinPipe()
+	enc.input = encInput
+	if err != nil {
+		logger.Error("can't get ffmpeg input pipe")
+	}
+	enc.cmd = cmd
+}
+func (enc *QTRLEImageEncoder) Run(videoFileName string) error {
+	if _, err := os.Stat(enc.FFMpegBinPath); os.IsNotExist(err) {
+		logger.Error("encoder file doesn't exist in path:", enc.FFMpegBinPath)
+		return errors.New("encoder file doesn't exist in path" + videoFileName)
+	}
+
+	enc.Init(videoFileName)
+	logger.Debugf("launching binary: %v", enc.cmd)
+	err := enc.cmd.Run()
+	if err != nil {
+		logger.Errorf("error while launching ffmpeg: %v\n err: %v", enc.cmd.Args, err)
+		return err
+	}
+	return nil
+}
+func (enc *QTRLEImageEncoder) Encode(img image.Image) {
+	if enc.input == nil || enc.closed {
+		return
+	}
+
+	err := encodePPM(enc.input, img)
+	if err != nil {
+		logger.Error("error while encoding image:", err)
+	}
+}
+
+func (enc *QTRLEImageEncoder) Close() {
+	enc.closed = true
+	//enc.cmd.Process.Kill()
+}
diff --git a/encoders/x264-enc.go b/encoders/x264-enc.go
index 02f98d2..12db9a5 100644
--- a/encoders/x264-enc.go
+++ b/encoders/x264-enc.go
@@ -15,10 +15,14 @@ type X264ImageEncoder struct {
 	cmd           *exec.Cmd
 	input         io.WriteCloser
 	closed        bool
+	Framerate     int
 }
 
 func (enc *X264ImageEncoder) Init(videoFileName string) {
 	fileExt := ".mp4"
+	if enc.Framerate == 0 {
+		enc.Framerate = 12
+	}
 	if !strings.HasSuffix(videoFileName, fileExt) {
 		videoFileName = videoFileName + fileExt
 	}
diff --git a/encoding_tight.go b/encoding_tight.go
index 0082815..7a1b4e2 100644
--- a/encoding_tight.go
+++ b/encoding_tight.go
@@ -367,9 +367,8 @@ func (enc *TightEncoding) drawTightPalette(rect *Rectangle, palette color.Palett
 			enc.Image.Set(int(rect.X)+x, int(rect.Y)+y, palette[palettePos])
 			//logger.Tracef("(%d,%d): pos: %d col:%d", int(rect.X)+j, int(rect.Y)+i, palettePos, palette[palettePos])
 		}
-		// if bitPos != 7 {
-		// 	bytePos++
-		// }
+
+		// reset bit alignment to first bit in byte (msb)
 		bitPos = 7
 	}
 
diff --git a/encoding_util.go b/encoding_util.go
index 252d1de..9c5010c 100644
--- a/encoding_util.go
+++ b/encoding_util.go
@@ -3,12 +3,18 @@ package vnc2video
 import (
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"image"
 	"image/color"
 	"image/draw"
 	"io"
 )
 
+const (
+	BlockWidth  = 16
+	BlockHeight = 16
+)
+
 type VncCanvas struct {
 	draw.Image
 	//DisplayBuff draw.Image
@@ -20,6 +26,7 @@ type VncCanvas struct {
 	CursorOffset   *image.Point
 	CursorLocation *image.Point
 	DrawCursor     bool
+	Changed        map[string]bool
 }
 
 func NewVncCanvas(width, height int) *VncCanvas {
@@ -33,6 +40,23 @@ func NewVncCanvas(width, height int) *VncCanvas {
 	return &canvas
 }
 
+func (c *VncCanvas) SetChanged(rect *Rectangle) {
+	if c.Changed == nil {
+		c.Changed = make(map[string]bool)
+	}
+	for x := int(rect.X) / BlockWidth; x*BlockWidth < int(rect.X+rect.Width); x++ {
+		for y := int(rect.Y) / BlockHeight; y*BlockHeight < int(rect.Y+rect.Height); y++ {
+			key := fmt.Sprintf("%d,%d", x, y)
+			//fmt.Println("setting block: ", key)
+			c.Changed[key] = true
+		}
+	}
+}
+
+func (c *VncCanvas) Reset(rect *Rectangle) {
+	c.Changed = nil
+}
+
 func (c *VncCanvas) RemoveCursor() image.Image {
 	if c.Cursor == nil || c.CursorLocation == nil {
 		return c.Image
diff --git a/encoding_util_test.go b/encoding_util_test.go
new file mode 100644
index 0000000..28e8b21
--- /dev/null
+++ b/encoding_util_test.go
@@ -0,0 +1,15 @@
+package vnc2video
+
+import "testing"
+
+func TestSetChanged(t *testing.T) {
+	canvas := &VncCanvas{}
+	rect := &Rectangle{X: 1, Y: 1, Width: 1024, Height: 64}
+	canvas.SetChanged(rect)
+	if canvas.Changed["64,0"] == false ||
+		canvas.Changed["64,1"] == false ||
+		canvas.Changed["64,4"] == false {
+		t.Fail()
+	}
+
+}