Diff: main.cpp

Revision:

0:436f1e857866

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Sat Apr 23 12:34:45 2011 +0000
@@ -0,0 +1,144 @@
+/*This program makes the WAV file of the sinewave in a local file. 
+The sampling frequency is 8KHz. In other words, it is the quality of the 
+telephone. The quantization precision is 16 bits. You can change the 
+frequency of the sinewave, the amplitude by changing a parameter in the 
+top of the program. You can change the file name, too. I suggest that 
+you make the plain name later. You can listen the wav file which You made 
+in Windows Mediaplayer.
+*/
+
+/*This program is made in reference to "Sound Programming in C Language" by Aoki Naofumi"*/
+
+#define FREQ 440 //Frequency (Hz) 
+#define AMP 0.5 //Amplitude 0 - 1
+#define FILE_NAME "/local/440_05.wav"  //Data file name max 8char.wav fffff_aa.wav
+
+#include "mbed.h"
+#include "TextLCD.h"
+
+TextLCD lcd(p24, p26, p27, p28, p29, p30);
+
+LocalFileSystem local("local");
+DigitalOut led_1(LED1);
+DigitalOut led_2(LED2);
+DigitalOut led_3(LED3);
+DigitalOut led_4(LED4);
+
+int main(void)
+{
+  typedef struct
+  {
+    int fs;
+    int bits;
+    int length;
+    double *s;
+  } MONO_PCM;
+  
+  FILE *fp;
+  MONO_PCM pcm;
+  int i, j;
+  double s;
+  short data;
+  double A, f0;
+  
+  char riff_chunk_ID[4];
+  long riff_chunk_size;
+  char riff_form_type[4];
+  char fmt_chunk_ID[4];
+  long fmt_chunk_size;
+  short fmt_wave_format_type;
+  short fmt_channel;
+  long fmt_samples_per_sec;
+  long fmt_bytes_per_sec;
+  short fmt_block_size;
+  short fmt_bits_per_sample;
+  char data_chunk_ID[4];
+  long data_chunk_size;
+  
+  lcd.cls();
+  lcd.locate(0,0);
+  lcd.printf("Audio wave\n");
+  
+  int block_length = 1000;
+  
+  pcm.fs = 8000;
+  pcm.bits = 16;
+  pcm.length = 40000; //about 5sec
+  pcm.s = (double*) calloc(block_length, sizeof(double)); 
+    
+  A = AMP;
+  f0 = FREQ;
+  
+  if ( NULL == (fp = fopen(FILE_NAME, "wb" )) )
+    error( "" );
+  
+  led_1 = 1;
+  riff_chunk_ID[0] = 'R';
+  riff_chunk_ID[1] = 'I';
+  riff_chunk_ID[2] = 'F';
+  riff_chunk_ID[3] = 'F';
+  riff_chunk_size = 36 + pcm.length * 2;
+  riff_form_type[0] = 'W';
+  riff_form_type[1] = 'A';
+  riff_form_type[2] = 'V';
+  riff_form_type[3] = 'E';
+  
+  fmt_chunk_ID[0] = 'f';
+  fmt_chunk_ID[1] = 'm';
+  fmt_chunk_ID[2] = 't';
+  fmt_chunk_ID[3] = ' ';
+  fmt_chunk_size = 16;
+  fmt_wave_format_type = 1;
+  fmt_channel = 1;
+  fmt_samples_per_sec = pcm.fs;
+  fmt_bytes_per_sec = pcm.fs * pcm.bits / 8;
+  fmt_block_size = pcm.bits / 8;
+  fmt_bits_per_sample = pcm.bits;
+  
+  data_chunk_ID[0] = 'd';
+  data_chunk_ID[1] = 'a';
+  data_chunk_ID[2] = 't';
+  data_chunk_ID[3] = 'a';
+  data_chunk_size = pcm.length * 2;
+  
+  fwrite(riff_chunk_ID, 1, 4, fp);
+  fwrite(&riff_chunk_size, 4, 1, fp);
+  fwrite(riff_form_type, 1, 4, fp);
+  fwrite(fmt_chunk_ID, 1, 4, fp);
+  fwrite(&fmt_chunk_size, 4, 1, fp);
+  fwrite(&fmt_wave_format_type, 2, 1, fp);
+  fwrite(&fmt_channel, 2, 1, fp);
+  fwrite(&fmt_samples_per_sec, 4, 1, fp);
+  fwrite(&fmt_bytes_per_sec, 4, 1, fp);
+  fwrite(&fmt_block_size, 2, 1, fp);
+  fwrite(&fmt_bits_per_sample, 2, 1, fp);
+  fwrite(data_chunk_ID, 1, 4, fp);
+  fwrite(&data_chunk_size, 4, 1, fp);
+  wait(0.5);
+  led_1 = 0;
+    
+  led_2 = 1;
+  for(i = 0; i < pcm.length/block_length; i++)
+  {
+
+    for (j = 0; j < block_length; j++)
+    { 
+      pcm.s[j] = A * sin(2.0 * 3.141592 * f0 * (i * block_length + j) / pcm.fs);
+      s = (pcm.s[j] + 1.0) / 2.0 * 65536.0;
+    
+      if (s > 65535.0) s = 65535.0; 
+      else if (s < 0.0) s = 0.0; 
+    
+      data = (short)(s + 0.5) - 32768;
+      fwrite(&data, 2, 1, fp);
+    }
+  }
+  led_2 = 0;
+  fclose(fp);   
+  free(pcm.s);
+  
+  lcd.locate(0,1);
+  lcd.printf("Done!\n");
+  
+  return 0;
+}
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