diff --git a/ChangeLog b/ChangeLog
index 97d1bc5..9d63661 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2023-02-16:
+- fixed positioncontrol. made some misstakes in calculating the angle
+  of the axsis vectors.
+- changed: convert function is now only presend in videodef class.
+
 2023-02-07:
 - position control is now working. has still some glitches
   with negative Kp, Ki and Kd values. But in general it is working.
diff --git a/error.h b/error.h
index 11343e3..5054759 100644
--- a/error.h
+++ b/error.h
@@ -15,6 +15,7 @@ struct ErrorMessage {
 	char message[ERRORMSG_LEN];
 };
 
+void errorexit (char *fmt,...);
 void errormessage_display (char *windowname, char *title, char *fmt,...);
 
 #endif    // _ERROR_H_
diff --git a/videodev-dummy.h b/videodev-dummy.h
index f222ffe..b696250 100644
--- a/videodev-dummy.h
+++ b/videodev-dummy.h
@@ -32,7 +32,7 @@ class VideoDev_Dummy: public VideoDev {
 private:
 	ConvertData cdata;
 
-	int Grab(VideoFrame *vf);
+	int Grab(VideoFrameRaw *vf);
 	int Open();
 	int Close();
 	int CaptureStart();
diff --git a/videodev-dumpfile.cc b/videodev-dumpfile.cc
index fc8aa17..02b0e8c 100644
--- a/videodev-dumpfile.cc
+++ b/videodev-dumpfile.cc
@@ -25,8 +25,6 @@
 #endif
 #include <sys/stat.h>
 
-
-#include "convert.h"
 #include "configuration.h"
 #include "videodev-dumpfile.h"
 
@@ -182,8 +180,7 @@ int VideoDev_Dumpfile::CaptureStart() {
 
 	// read timestamp and first header and frame
 	gettimeofday(&starttv, NULL);
-
-	ConvertStart(&cdata, pixformat);
+	pixelformat = pixformat;
 	ReadFrame();
 
 	return VDEV_STATUS_OK;
@@ -203,9 +200,6 @@ int VideoDev_Dumpfile::CaptureStop() {
 		inframe_size = 0;
 		inframe = NULL;
 	}
-
-	ConvertStop(&cdata, pixformat);
-
 	return VDEV_STATUS_OK;
 };
 
@@ -215,7 +209,7 @@ int VideoDev_Dumpfile::CaptureStop() {
  * If something goes wrong return an error code.
  * Return code VDEV_STATUS_AGAIN is not an error. There was no video image ready to read.
  */
-int VideoDev_Dumpfile::Grab(VideoFrame *vf) {
+int VideoDev_Dumpfile::Grab(VideoFrameRaw *vf) {
 	struct timeval curtv;
 	unsigned int diff = 0;
 
@@ -237,7 +231,7 @@ int VideoDev_Dumpfile::Grab(VideoFrame *vf) {
 				__FILE__, __LINE__, (diff - inframe_nexttime));
 
 	LockMutex();
-	Convert(&cdata, vf, inframe, inframe_size, pixformat, w, h);
+	vf->CopyFrom(pixformat, w, h, inframe_size, inframe);
 	UnLockMutex();
 
 	//
diff --git a/videodev-dumpfile.h b/videodev-dumpfile.h
index 1dbca4e..b099047 100644
--- a/videodev-dumpfile.h
+++ b/videodev-dumpfile.h
@@ -21,8 +21,6 @@
 #include <list>
 #include <string>
 
-
-#include "convert.h"
 #include "gui.h"
 #include "videodev.h"
 
@@ -42,7 +40,7 @@ private:
 	int inframe_maxsize;
 	int inframe_size;
 
-	int Grab(VideoFrame *vf);
+	int Grab(VideoFrameRaw *vf);
 	int Open();
 	int Close();
 	int CaptureStart();
diff --git a/videodev-simulation.cc b/videodev-simulation.cc
index 678fc6c..9703846 100644
--- a/videodev-simulation.cc
+++ b/videodev-simulation.cc
@@ -107,7 +107,7 @@ int VideoDev_Simulation::CaptureStart() {
 
 	if (inframe != NULL) Close();
 	if (Open() != VDEV_STATUS_OK) return VDEV_STATUS_ERROR;
-	ConvertStart(&cdata, V4L2_PIX_FMT_RGB24);
+	pixelformat = V4L2_PIX_FMT_RGB24;
 	get_cycletime(&lastframetv);
 
 	return VDEV_STATUS_OK;
@@ -118,7 +118,6 @@ int VideoDev_Simulation::CaptureStop() {
 	printf ("%s:%d %s\n", __FILE__, __LINE__, __FUNCTION__);
 
 	if (inframe != NULL) Close();
-	ConvertStop(&cdata, V4L2_PIX_FMT_RGB24);
 	return VDEV_STATUS_OK;
 };
 
@@ -129,7 +128,7 @@ int VideoDev_Simulation::CaptureStop() {
  * Return code VDEV_STATUS_AGAIN is not an error. There was no video image ready to read.
  */
 #define SIMULATION_SIZE 16
-int VideoDev_Simulation::Grab(VideoFrame *vf) {
+int VideoDev_Simulation::Grab(VideoFrameRaw *vf) {
 	int posx, posy, x ,y, r, radius;
 	double a, dsec;
 
@@ -152,8 +151,7 @@ int VideoDev_Simulation::Grab(VideoFrame *vf) {
 	}
 
 	LockMutex();
-	Convert(&cdata, vf, inframe, (conf_width*conf_height*3), V4L2_PIX_FMT_RGB24,
-			conf_width, conf_height);
+	vf->CopyFrom(V4L2_PIX_FMT_RGB24, conf_width, conf_height, (conf_width*conf_height*3), inframe);
 	UnLockMutex();
 
 	return VDEV_STATUS_OK;
diff --git a/videodev-simulation.h b/videodev-simulation.h
index 9051636..e85fce5 100644
--- a/videodev-simulation.h
+++ b/videodev-simulation.h
@@ -72,7 +72,7 @@ private:
 	ConvertData cdata;
 	GThread *simulation_thread;
 
-	int Grab(VideoFrame *vf);
+	int Grab(VideoFrameRaw *vf);
 	int Open();
 	int Close();
 	int CaptureStart();
diff --git a/videodev-svbcam.cc b/videodev-svbcam.cc
index c8b069c..d9b3f7e 100644
--- a/videodev-svbcam.cc
+++ b/videodev-svbcam.cc
@@ -289,8 +289,7 @@ int VideoDev_SVBCam::CaptureStart() {
 	if (inframe != NULL) free (inframe);
 	inframe_size = 4 * inframe_w * inframe_h;
 	inframe = (unsigned char*) malloc(inframe_size);
-
-	ConvertStart(&cdata, inframe_pixfmt);
+	pixelformat = inframe_pixfmt;
 
 	return VDEV_STATUS_OK;
 };
@@ -315,8 +314,6 @@ int VideoDev_SVBCam::CaptureStop() {
 		inframe_size = 0;
 	}
 
-	ConvertStop(&cdata, inframe_pixfmt);
-
 	return VDEV_STATUS_OK;
 };
 
@@ -327,7 +324,7 @@ int VideoDev_SVBCam::CaptureStop() {
  * Return code VDEV_STATUS_AGAIN is not an error. There was no video image ready to read.
  */
 // FIXME: SVBGetVideoData needs to be outside of Lock/UnLockMutex - using inside thread inbuffer
-int VideoDev_SVBCam::Grab(VideoFrame *vf) {
+int VideoDev_SVBCam::Grab(VideoFrameRaw *vf) {
 	int err;
 
 	if (inframe == NULL) return VDEV_STATUS_ERROR;
@@ -339,7 +336,7 @@ int VideoDev_SVBCam::Grab(VideoFrame *vf) {
 		}
 	}
 	LockMutex();
-	Convert(&cdata, vf, inframe, inframe_size, inframe_pixfmt, inframe_w, inframe_h);
+	vf->CopyFrom(inframe_pixfmt, inframe_w, inframe_h, inframe_size, inframe);
 	UnLockMutex();
 
 	return VDEV_STATUS_OK;
diff --git a/videodev-svbcam.h b/videodev-svbcam.h
index a5e51da..7a1ce44 100644
--- a/videodev-svbcam.h
+++ b/videodev-svbcam.h
@@ -44,7 +44,7 @@ private:
 	ConvertData cdata;
 	int camid;
 
-	int Grab(VideoFrame *vf);
+	int Grab(VideoFrameRaw *vf);
 	int Open();
 	int Close();
 	int CaptureStart();
diff --git a/videodev-v4l2.cc b/videodev-v4l2.cc
index 16c366f..bf1f684 100644
--- a/videodev-v4l2.cc
+++ b/videodev-v4l2.cc
@@ -395,7 +395,7 @@ int VideoDev_V4L2::CaptureStart() {
 		return VDEV_STATUS_ERROR;
 	}
 
-	ConvertStart(&cdata, fmt.fmt.pix.pixelformat);
+	pixelformat = fmt.fmt.pix.pixelformat;
 
 	return VDEV_STATUS_OK;
 };
@@ -405,8 +405,6 @@ int VideoDev_V4L2::CaptureStop() {
     enum v4l2_buf_type type;
 	printf ("%s:%d %s\n", __FILE__, __LINE__, __FUNCTION__);
 
-	ConvertStop(&cdata, fmt.fmt.pix.pixelformat);
-
     switch (io) {
     case IOMODE_READ:
             /* Nothing to do. */
@@ -431,7 +429,7 @@ int VideoDev_V4L2::CaptureStop() {
  * If something goes wrong return an error code.
  * Return code VDEV_STATUS_AGAIN is not an error. There was no video image ready to read.
  */
-int VideoDev_V4L2::Grab(VideoFrame *vf) {
+int VideoDev_V4L2::Grab(VideoFrameRaw *vf) {
 	struct v4l2_buffer buf;
 	int len;
 
@@ -451,7 +449,7 @@ int VideoDev_V4L2::Grab(VideoFrame *vf) {
 		}
 		else {
 			LockMutex();
-			Convert(&cdata, vf, inbuffer[0].data, len, fmt.fmt.pix.pixelformat, fmt.fmt.pix.width, fmt.fmt.pix.height);
+
 			UnLockMutex();
 		}
 		break;
@@ -477,7 +475,7 @@ int VideoDev_V4L2::Grab(VideoFrame *vf) {
 
 		if (buf.index >= 0 && buf.index < VDEV_INBUFFERS) {
 			LockMutex();
-			Convert(&cdata, vf, inbuffer[buf.index].data, buf.bytesused, fmt.fmt.pix.pixelformat, fmt.fmt.pix.width, fmt.fmt.pix.height);
+			vf->CopyFrom(fmt.fmt.pix.pixelformat, fmt.fmt.pix.width, fmt.fmt.pix.height, buf.bytesused, inbuffer[buf.index].data);
 			UnLockMutex();
 		}
 
diff --git a/videodev-v4l2.h b/videodev-v4l2.h
index 2b0cd3d..858e1c1 100644
--- a/videodev-v4l2.h
+++ b/videodev-v4l2.h
@@ -46,9 +46,7 @@ private:
 	struct v4l2_crop crop;
 	struct v4l2_format fmt;
 
-	ConvertData cdata;
-
-	int Grab(VideoFrame *vf);
+	int Grab(VideoFrameRaw *vf);
 	int Open();
 	int Close();
 	int CaptureStart();
diff --git a/videodev-vfw.cc b/videodev-vfw.cc
index 7d53f4f..b4df1c6 100644
--- a/videodev-vfw.cc
+++ b/videodev-vfw.cc
@@ -19,6 +19,11 @@ VideoDev_VFW::VideoDev_VFW() {
 	printf ("%s:%d %s\n", __FILE__, __LINE__, __FUNCTION__);
 	cap = NULL;
 	camid = -1;
+	inframe_pixfmt = 0x0;
+	inframe_w = -1;
+	inframe_h = -1;
+	inframe = NULL;
+	inframe_size = 0;
 };
 
 
@@ -176,7 +181,7 @@ int VideoDev_VFW::CaptureStart() {
 	  printf ("%s:%d %s Could not set frame callback to VFW id %d\n", __FILE__, __LINE__, __FUNCTION__, camid);
 	}
 	
-	ConvertStart(&cdata, inframe_pixfmt);
+	pixelformat = inframe_pixfmt;
 
 	return VDEV_STATUS_OK;
 };
@@ -192,7 +197,6 @@ int VideoDev_VFW::CaptureStop() {
 	capCaptureAbort(cap);
 	capSetCallbackOnError(cap, NULL);
 	capSetCallbackOnFrame(cap, NULL);
-	ConvertStop(&cdata, inframe_pixfmt);
 	return VDEV_STATUS_OK;
 };
 
@@ -202,12 +206,12 @@ int VideoDev_VFW::CaptureStop() {
  * Return code VDEV_STATUS_AGAIN is not an error. There was no video image ready to read.
  */
 // FIXME: SVBGetVideoData needs to be outside of Lock/UnLockMutex - using inside thread inbuffer
-int VideoDev_VFW::Grab(VideoFrame *vf) {
+int VideoDev_VFW::Grab(VideoFrameRaw *vf) {
 
   //if (inframe == NULL) return VDEV_STATUS_ERROR;
 
 	LockMutex();
-	Convert(&cdata, vf, VFW_frame_buffer, VFW_frame_size, inframe_pixfmt, conf_width, conf_height);
+	vf->CopyFrom(inframe_pixfmt, conf_width, conf_height, VFW_frame_size, VFW_frame_buffer)
 	UnLockMutex();
 	
 	return VDEV_STATUS_OK;
diff --git a/videodev-vfw.h b/videodev-vfw.h
index 561247d..995dee7 100644
--- a/videodev-vfw.h
+++ b/videodev-vfw.h
@@ -13,9 +13,9 @@ private:
 
 	ConvertData cdata;
 	int camid;
-        HWND cap;
+    HWND cap;
 
-	int Grab(VideoFrame *vf);
+	int Grab(VideoFrameRaw *vf);
 	int Open();
 	int Close();
 	int CaptureStart();
diff --git a/videodev.cc b/videodev.cc
index e9317ec..1988abe 100644
--- a/videodev.cc
+++ b/videodev.cc
@@ -26,6 +26,7 @@
 #include "video.h"
 #include "videoframe.h"
 #include "videodev.h"
+#include "convert.h"
 
 
 VideoDev::VideoDev() {
@@ -38,6 +39,7 @@ VideoDev::VideoDev() {
 	conf_width = 600;
 	running = 0;
 	callback = NULL;
+	pixelformat = 0x0;
 	g_mutex_init (&mutex);
 };
 
@@ -162,14 +164,18 @@ void VideoDev::ThreadProcess() {
 		running = 0;
 	}
 
+	if (running) {
+		ConvertStart(&cdata, pixelformat);
+	}
+
 	threaddata.running = 1;	// prevent reading all controlls every time.
 							// will be set to 2 in callback function, after the first frame
 							// is read and all controls a loaded.
 	if (callback) gdk_threads_add_idle(callback, &threaddata);
 
 	while (running) {
-		i = Grab(&threaddata.vf);
-
+		i = Grab(&threaddata.vfr);
+		Convert(&cdata, &threaddata.vf, threaddata.vfr.data, threaddata.vfr.size, threaddata.vfr.pixfmt, threaddata.vfr.w, threaddata.vfr.h);
 		switch (i) {
 		case VDEV_STATUS_OK:
 			if (callback) gdk_threads_add_idle(callback, &threaddata);
@@ -196,6 +202,7 @@ void VideoDev::ThreadProcess() {
 	//
 	// stop capturing
 	if (callback) gdk_threads_add_idle(callback, NULL);
+	ConvertStop(&cdata, pixelformat);
 	CaptureStop();
 	Close();
 
diff --git a/videodev.h b/videodev.h
index 21c4528..03271e0 100644
--- a/videodev.h
+++ b/videodev.h
@@ -66,6 +66,7 @@ struct {
 struct {
 	int running;
 	VideoFrame vf;
+	VideoFrameRaw vfr;
 } typedef VideoDevThreadData;
 
 #ifndef CLEAR
@@ -85,13 +86,14 @@ private:
 	std::string conf_devicename;		// human friendly name of the device
 	std::string conf_format;			// video or image format (should every device have)
 	std::string conf_parameter; 		// can hold additional parameters
+	uint32_t pixelformat;				// pixelformat
 	int conf_height;
 	int conf_width;
 
 	int running;						// 0 ... not running
 										// 1 ... initialized (init, first frame)
 										// 2 ... running
-
+	ConvertData cdata;
 
 	GMutex mutex;
 	gboolean (*callback)(gpointer data);
@@ -101,7 +103,7 @@ private:
 	std::list<VideoDevCtrl> vidctrls;
 
 	/* grabs a single frame, writes the RGB24 converted frame to the VideoFrame pointer */
-	virtual int Grab(VideoFrame *vf) { return VDEV_STATUS_AGAIN; };
+	virtual int Grab(VideoFrameRaw *vf) { return VDEV_STATUS_AGAIN; };
 
 	/* opens the device, will need to fill the controls as well */
 	virtual int Open()  { return VDEV_STATUS_OK; };
diff --git a/videoframe.cc b/videoframe.cc
index 26fc97e..88c7a9e 100644
--- a/videoframe.cc
+++ b/videoframe.cc
@@ -1,11 +1,74 @@
 
+#include <errno.h>
 #include <string.h>
 #include "video.h"
 #include "config.h"
 #include "gui.h"
+#include "error.h"
 
-#define VIDEOFRAME_DEPTH_BYTES 3
+VideoFrameRaw::VideoFrameRaw() {
+	size = 0;
+	data = NULL;
+	w = 0;
+	h = 0;
+	pixfmt = 0x0;
+}
+
+VideoFrameRaw::~VideoFrameRaw() {
+	if (data != NULL) {
+		free (data);
+		data = NULL;
+	}
+}
+
+
+int VideoFrameRaw::CopyFrom(int spixfmt, int sw, int sh, int ssize, unsigned char *sdata) {
+	if (size != ssize) {
+		if (ReAlloc(ssize) != 0) {
+			errorexit((char*) "%s:%d %s could not reallocate memory. Error:%s\n",
+					__FILE__, __LINE__, __FUNCTION__, strerror(errno));
+		}
+	}
+
+	if (data == NULL) {
+		errorexit((char*) "%s:%d %s invalid pointer of data. Error:%s\n",
+				__FILE__, __LINE__, __FUNCTION__, strerror(errno));
+	}
 
+	w = sw;
+	h = sh;
+	pixfmt = spixfmt;
+	memcpy (data, sdata, size);
+
+	return 0;
+}
+
+
+int VideoFrameRaw::ReAlloc(int newsize) {
+	unsigned char *newdata = NULL;
+	if (newsize == 0) {
+		free (data);
+		data = NULL;
+		size = newsize;
+		return 0;
+	}
+	if (data == NULL) {
+		if ((data = (unsigned char*) malloc (newsize)) == NULL) return -1;
+	}
+	else if (size < newsize || size > newsize) {
+		if ((newdata = (unsigned char*) realloc (data, newsize)) == NULL) {
+			free (data);
+			size = 0;
+			return -1;
+		}
+		data = newdata;
+	}
+	size = newsize;
+	return 0;
+}
+
+
+#define VIDEOFRAME_DEPTH_BYTES 3
 VideoFrame::VideoFrame() {
 	data = NULL;
 	w = 0;
diff --git a/videoframe.h b/videoframe.h
index 7e46673..f87a3dc 100644
--- a/videoframe.h
+++ b/videoframe.h
@@ -4,6 +4,21 @@
 #include "gui.h"
 #include "config.h"
 
+class VideoFrameRaw {
+private:
+public:
+	unsigned char *data;
+	int size;
+	int w;
+	int h;
+	uint32_t pixfmt;
+	VideoFrameRaw();
+	~VideoFrameRaw();
+	int ReAlloc(int newsize);
+	int CopyFrom(int spixfmt, int sw, int sh, int ssize, unsigned char *sdata);
+};
+
+
 
 class FloatImage {
 public: