Screenshots using GUI_BMP_SerializeExBpp

kain2609 · July 27, 2015 at 10:56 AM

Hello,

i am using emWin in one of our µ-Controller Projects. I try to make a 'screenshot' of the GUI using the following Code:

C

char buffer[100];
int counter;


static void _WriteByte2File(U8 Data, void * p)
 {	
  FILE* bmpFile;	
  bmpFile = (FILE*) p;
  buffer[counter] = Data;
  counter++;		
  if (counter == 100) 	
  {		
    fwrite(&buffer, sizeof(U8), counter, bmpFile);			 
    fflush(bmpFile);				
    counter = 0;		
  }
}


static void vMakeScreenshot() 
{		
  FILE * bmpFile;	
  counter = 0;		
  bmpFile = fopen( 	"M0:\\temp\\temp.bmp", "w" );		
  GUI_BMP_SerializeExBpp( _WriteByte2File, 320, 240, 50, 50, bmpFile, 16);		 
  // Write rest of buffer		
  fwrite(&buffer, sizeof(U8), counter, bmpFile);		
  fflush(bmpFile);		
  fclose(bmpFile);
}

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However, i can't get a working screenshot. Am i doing something wrong here? While debugging i also saw that 'Data' ist just 0x00 most of the time. Is this correct?!

Hope someone can help me with this.

Thanks in advance and kind Regards

SEGGER - Adrian · July 28, 2015 at 9:15 AM

Hello,

Please note that you have a global and a local array called "buffer".

Best regards,
Adrian

kain2609 · July 28, 2015 at 10:27 AM

Hey Adrian,

why do you think i got a local "buffer" array? It is just declared globally and i use it in both functions.

Kind Regards

SEGGER - Adrian · July 29, 2015 at 9:13 AM

Hello,

I am sorry. It seemed to me that this identifier has been declared twice.

Please note that the function GUI_BMP_SerializeExBpp() uses 320, 240 as starting positions. Could you please tell me what is the dimension of your display? Thank you.

Best regards,
Adrian

kain2609 · July 29, 2015 at 12:16 PM

Hey Adrian,

the dimension is 640x480. I just tested the center of the screen.

Kind Regards,

SEGGER - Adrian · July 30, 2015 at 9:50 AM

Hello,

This function works very well on my end. If most of your data is 0x00, does this match the part of the screen which has to be stored as BMP file?

Best regards,
Adrian

kain2609 · July 31, 2015 at 11:54 AM

Hey Adrian,

i figured out one error in my software when i tried to copy the Bitmap over Ethernet, now i access it directly from my sd card.

However, i just get unicolored bitmaps, for example i tried to save a 320x240 screenshot but the bitmap is just completely red (i uploaded it as attachement).

Do you have any idea why this is that way?

Kind Regards,

SEGGER - Adrian · August 3, 2015 at 10:41 AM

Hello,

Please note that the function GUI_BMP_SerializeExBpp() reads the pixel data out of the currently selected device. This can be a Memory Device.

Best regards,
Adrian

kain2609 · August 3, 2015 at 12:55 PM

Hey Adrian,

okay, i just want to write the content of the LCD to the BMP file.
I inserted

Code

GUI_MEMDEV_Select(0);

just before GUI_BMP_SerializeExBpp, but the Bitmaps are still empty. Or do i have to use a memory device to get the Bitmap?

Kind Regards

SEGGER - Adrian · August 4, 2015 at 9:47 AM

Hello,

Please make sure that the function to which a pointer is passed as parameter to GUI_BMP_SerializeExBpp() works correctly.

Best regards,
Adrian

kain2609 · August 4, 2015 at 1:37 PM

Hey Adrian,

i posted my function in the first post and you said that this function works very well on your end?

Even if i debug and step through my implementation, i see that the Bytes passed to the

C

_WriteByte2File

function are correctly written into the buffer array and then to the file.

Kind Regards,

SEGGER - Adrian · August 5, 2015 at 9:24 AM

Hello,

The function GUI_BMP_SerializeExBpp() works on my end. I did not test your _WriteByte2File() function.

Best regards,
Adrian

kain2609 · August 5, 2015 at 12:50 PM

Hey Adrian,

the '_WriteByte2File()' seemed to work well, the header of the Bitmap is written correct.
However i simplified the function to write each byte instantly to the file:

C

static void _WriteByte2File(U8 Data, void * p)
 {	
  FILE* bmpFile;	
  bmpFile = (FILE*) p;
  fwrite(&Data, sizeof(U8), 1, bmpFile);			 
  fflush(bmpFile);				
}


static void vMakeScreenshot() 
{		
  FILE * bmpFile;	
	GUI_MEMDEV_Select(0);	
  bmpFile = fopen( 	"M0:\\temp\\temp.bmp", "w" );		
  GUI_BMP_SerializeExBpp( _WriteByte2File, 0, 0, 20, 20, bmpFile, 8);		 	
  fclose(bmpFile);
}

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So this does not seem to be the error, since i got *.bmp Files that i can open with any ImageViewer. However, the image is still just black.
Do i have to change something else?
Is the way i select the LCD as device the wrong way?

Kind Regards,

kain2609 · August 10, 2015 at 3:33 PM

Hello,

i digged more into our implementation and saw the following:
We are using the 'GUIDRV_FLEXCOLOR'-Driver and the mode 'GUICC_M565'.
When i try to take the screenshot using 'GUI_BMP_Serialize' the function 'pfReadM16_A1' is called multiple times to read the data from the LCD.

C

void pfReadM16_A1( unsigned short * pData, int iNumItems ) 
{
  for( ; iNumItems; iNumItems-- )
  {
  	*pData = *m_pusLCDReadData;
  	pData++;
  }
}

For example this function returns 3 2-byte-elements:
0xF79E
0xF79E
0x0000

The BMP-File is generated by:

C

static void _WriteByte2File(U8 Data, void * p)
 {	
  FILE* bmpFile;	
  bmpFile = (FILE*) p;
  fwrite(&Data, sizeof(U8), 1, bmpFile);			 
  fflush(bmpFile);				
}


static void vMakeScreenshot() 
{		
  FILE * bmpFile;	
  bmpFile = fopen("M0:\\temp\\temp.bmp", "w" );		
  GUI_BMP_Serialize( _WriteByte2File, bmpFile);
  fclose(bmpFile);
}

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The '_WriteByte2File' functions works as expected since every byte that is passed to it can be found in the resulting BMP-file later on.
But:
After some 'header'(?) the BMP-File justs consists of 0x4C and 0x00 bytes (i attached a screenshot with a hexadecimal view of the file) but the data that is read by the 'pfReadM16_A1' function never occurs in the BMP-File.

Do you have any ideas where the error could be or how i could investigate the problem more?

Kind Regards,

SEGGER - Adrian · August 11, 2015 at 11:03 AM

Hello,

Can you please provide your configuration file LCDConf.c. I would like to have a deeper look at this. Thank you.

Best regards,
Adrian

kain2609 · August 11, 2015 at 11:23 AM

Hello,

this is the LCDConf.c
(i attached the file because the post was too long)

And these are the defined API functions:

C

/**********************************************************************************************/
/*	FUNKTION FÜR GUI : Kommando an LCD Controller schreiben (Adressleitung A0 = 0)						*/
/*	!!!	Der Treiber der GUI verwendet die Funktion für den Zugriff auf den LCD Controller.		*/
/*	!!!	Der Inhalt der Funktion muss entsprechend dem verwendeten Controller angepasst sein.	*/	
/**********************************************************************************************/
void vLCD_WriteCommand( unsigned short usData )
{
	*m_pusLCDWriteCommand = usData;
}	


/**********************************************************************************************/
/*	FUNKTION FÜR GUI : Datenbyte an LCD Controller schreiben (Adressleitung A0 = 1)						*/
/*	!!!	Der Treiber der GUI verwendet die Funktion für den Zugriff auf den LCD Controller.		*/
/*	!!!	Der Inhalt der Funktion muss entsprechend dem verwendeten Controller angepasst sein.	*/	
/**********************************************************************************************/
void vLCD_WriteData( unsigned short usData )
{
	*m_pusLCDWriteData = usData;
}	


/**********************************************************************************************/
/*	FUNKTION FÜR GUI : Mehrere Datenbytes an LCD Controller schreiben (Adressleitung A0 = 1)	*/
/*	!!!	Der Treiber der GUI verwendet die Funktion für den Zugriff auf den LCD Controller.		*/
/*	!!!	Der Inhalt der Funktion muss entsprechend dem verwendeten Controller angepasst sein.	*/	
/**********************************************************************************************/
void vLCD_WriteMultipleData( unsigned short * pData, int iNumItems )
{
  for( ; iNumItems; iNumItems-- )
   { *m_pusLCDWriteData = (*pData++); }
}


/**********************************************************************************************/
/*	FUNKTION FÜR GUI : Mehrere Datenbytes von LCD Controller lesen (Adressleitung A1 = 1)			*/
/*	!!!	Der Treiber der GUI verwendet die Funktion für den Zugriff auf den LCD Controller.		*/
/*	!!!	Der Inhalt der Funktion muss entsprechend dem verwendeten Controller angepasst sein.	*/	
/**********************************************************************************************/
void vLCD_ReadMultipleData( unsigned short * pData, int iNumItems )
{
	for( ; iNumItems; iNumItems-- )
		{
			*pData = *m_pusLCDReadData;
			pData++;
		}
}

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SEGGER - Adrian · August 13, 2015 at 10:33 AM

Hello,

Thank you for sending your configuration file. I was able to find a problem which is hopefully caused for the same reason as the one you are experiencing. We will have to have a closer look at this.

What I can tell for now is that the problem I found does not occur when using a display driver cache. You are currently using the GUIDRV_FLEXCOLOR_M16C0B16 mode. The cache can be enabled using GUIDRV_FLEXCOLOR_M16C0B16. Please note that a cache requires additional RAM. Please refer to the chapter "Display drivers" in the emWin user manual for details on how to calculate the exact size.

Of course the problem will be solved in a future emWin version.

Best regards,
Adrian

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