PSD binary file format

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gg20000

PSD binary file format

Post by gg20000 » Fri May 14, 2004 5:43 am

I used a ADC216 with the Picoscope s/w to record a signal @ max sampling freq - ie 333kS.s-1. I need to import ALL samples o fth etime history in a third party software in binary form. To do so, I ll need the exact format of the binary file .PSD created: number of bytes, format, structure, resolution, precision.
The help file is more than vague on that matter.
Pico Team early reply would be greatly appreciated !
\Jerome.

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markspencer
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Post by markspencer » Fri May 14, 2004 9:32 am

Hi,

Thank you for your post.

I have checked the help file and we believe that this may have gone out of date. I am going to have a look at this and will post my results. Unfortunately, this may take a few days to get a definitive answer.

Best regards,
Regards,

Mark Spencer

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Post by markspencer » Tue May 25, 2004 3:20 pm

Hi,

This should help those who wish to get data out of a .psd file. It has been tested on a ADC212 range, but should work with out change with a ADC-216, and 200's.

The help manual states that the Times came first, where infact they are the last part.

Code: Select all

#include <windows.h>
#include <stdio.h>
#include <assert.h>

#define FILEPSD2 "test.psd" // name of file

// used to check that the .psd file has not been saved commpressed
#define COMPRESSED_FLAG 0x80000000UL

// PSD EOF marker
#define PS_EOF 10

// PSD header
typedef struct
{
	short owner;
    short section_type;
	short section_no;
	short no_of_parts;
} PSDHEADER;


void main(void)
{
	FILE *fp;
    PSDHEADER header;
	BOOL ok;
    HANDLE hFile;
	DWORD nb;
    DWORD length;
	short *channel1_adc, *channel2_adc;
	long *times;
	int part = 0;
	long no_of_samples, i;
	char single[200];
	int lth;
	short number_of_channels;

	no_of_samples = 0;
 
    hFile = CreateFile(FILEPSD2, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_READONLY, NULL);


	if (hFile == INVALID_HANDLE_VALUE)
		exit (0);

	number_of_channels = 1;

    ok = ReadFile(hFile, &header, sizeof(PSDHEADER), &nb, NULL);

	ReadFile(hFile, &length, sizeof(DWORD), &nb, NULL);
    SetFilePointer (hFile, length, NULL, FILE_CURRENT);

    //enter a loop and keep going
	//until either PS_EOF is reached or some DATA is found.

    while (header.section_type != PS_EOF)
	{
    // read the header
      ok = ReadFile(hFile, &header, sizeof(PSDHEADER), &nb, NULL);

	  // if the header is of type 1 or 2 get the data and times
	  if(header.section_type == 1 || header.section_type == 2)
	  {
		  // Always Part1 read settings, and discard
	      ReadFile(hFile, &length, sizeof(DWORD), &nb, NULL);
          ReadFile(hFile, (BYTE *) &single, length, &nb, NULL);

		  // Number of bytes making up part 2
		  ReadFile(hFile, &length, sizeof(DWORD), &nb, NULL);
		  
		  // check the file is not compressed.
          if(length & COMPRESSED_FLAG)
		  {
			  printf("The data is compressed");
			  exit (0);  
		  }
		  else
		  {
             channel1_adc = (short *) malloc (length);
             ok = ReadFile(hFile, channel1_adc, length, &nb, NULL);
		  }

		  // if you are using 2 channels on the ADC-2xx and ADC-100 units
		  if(header.section_type == 2)
		  {
			// number of channels used set to 2
			number_of_channels = 2;
			// read the number of bytes in part 3
            ReadFile(hFile, &length, sizeof(DWORD), &nb, NULL);
		    // check that the file is not compressed
            if(length & COMPRESSED_FLAG)
			{
			  printf("The data is compressed");
			  exit (0);  
			}
		    else
			{
              channel2_adc = (short *) malloc (length);
              ok = ReadFile(hFile, channel2_adc, length, &nb, NULL);
			}
		  }

	      // if only one channels is used read the number of bytes in part 3
		  // if 2 channels have been used then this will be part 4
		  ReadFile(hFile, &length, sizeof(DWORD), &nb, NULL);
	      // check that the file is not compressed
          if(length & COMPRESSED_FLAG)
		  {
			  printf("The data is compressed");
			  exit (0);
		  }
		  else
		  {
   	      times = (long *) malloc (length);
	      ok = ReadFile(hFile, times, length, &nb, NULL);
		  no_of_samples = length / 4;
		  }

	  }
	  else
	  {
		 // move the file pointer on the number of bytes, this is not needed.
         part = 0;
	     if (times)
		 {
		    while (part < header.no_of_parts)
			{		    
			   ReadFile(hFile, &length, sizeof(DWORD), &nb, NULL);
		       ok = SetFilePointer (hFile, length, NULL, FILE_CURRENT);
		       part++;
			}
		 }
	  }
	}
    
	// write data in to the .txt file.
    if(no_of_samples > 0)
    {
		fp = fopen (FILETXT, "w");
		if (fp)
		{
		   fprintf(fp, "Channel A\nTimes, ADC\n");
	       for (i = 0; i < no_of_samples; i++)
		   {
			  fprintf(fp, "%ld, %d\n", times[i], channel1_adc[i]);
		   }

		   if(number_of_channels == 2)
		   {
		      fprintf(fp, "\nChannel B\nTimes, ADC\n");
	          for (i = 0; i < no_of_samples; i++)
			  {
			     fprintf(fp, "%ld, %d\n", times[i], channel2_adc[i]);
			  }
		   }


		   fclose(fp);
		}
    }

    free (times);

    free (channel1_adc);


	if (number_of_channels == 2)
	{
	  free (channel2_adc);
	}

    CloseHandle(hFile);
}
Best regards,
Regards,

Mark Spencer

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