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bytemedia

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morse.c (3171B)

    

  1. // echo 'hello world' | ./morse | $PLAYER -
  2. // $PLAYER: Any au(5) aware audio player (sox's play(1), mpv, …)
  3. #define _POSIX_C_SOURCE 200809L
  4. #include "au.h"
  6. #include <inttypes.h> // uint32_t
  7. #include <stdio.h>    // getchar(), putchar(), fputs()
  9. // Fuckings to GNU; Love to musl libc
  10. // https://drewdevault.com/2020/09/25/A-story-of-two-libcs.html
  11. int
  12. isalpha(int c)
  13. {
  14. 	return ((unsigned)c | 32) - 'a' < 26;
  15. }
  17. int
  18. isdigit(int c)
  19. {
  20. 	return (unsigned)c - '0' < 10;
  21. }
  23. int
  24. isalnum(int c)
  25. {
  26. 	return isalpha(c) || isdigit(c);
  27. }
  29. int
  30. toupper(int c)
  31. {
  32. 	// 'A' - 'a' = -32
  33. 	return c - 32;
  34. }
  36. /*
  37.  * Morse:
  38.  *
  39.  * dot: 1 unit
  40.  * dash: 3 units
  41.  * dot/dash gap: 1 unit
  42.  * letter gap: 3 units
  43.  * word gap: 7 units
  44.  */
  46. // 'Z' = 0d90
  47. static char *morse_itu[91];
  49. int
  50. morse_init()
  51. {
  52. 	morse_itu['A'] = ". ---";
  53. 	morse_itu['B'] = "--- . . .";
  54. 	morse_itu['C'] = "--- . --- .";
  55. 	morse_itu['D'] = "--- . .";
  56. 	morse_itu['E'] = ".";
  57. 	morse_itu['F'] = ". . --- .";
  58. 	morse_itu['G'] = "--- --- .";
  59. 	morse_itu['H'] = ". . . .";
  60. 	morse_itu['I'] = ". .";
  61. 	morse_itu['J'] = ". --- --- ---";
  62. 	morse_itu['K'] = "--- . ---";
  63. 	morse_itu['L'] = ". --- . .";
  64. 	morse_itu['M'] = "--- ---";
  65. 	morse_itu['N'] = "--- .";
  66. 	morse_itu['O'] = "--- --- ---";
  67. 	morse_itu['P'] = ". --- --- .";
  68. 	morse_itu['Q'] = "--- --- . ---";
  69. 	morse_itu['R'] = ". --- .";
  70. 	morse_itu['S'] = ". . .";
  71. 	morse_itu['T'] = "---";
  72. 	morse_itu['U'] = ". . ---";
  73. 	morse_itu['V'] = ". . . ---";
  74. 	morse_itu['W'] = ". --- ---";
  75. 	morse_itu['X'] = "--- . . ---";
  76. 	morse_itu['Y'] = "--- . --- ---";
  77. 	morse_itu['Z'] = "--- --- . .";
  78. 	morse_itu['1'] = ". --- --- --- ---";
  79. 	morse_itu['2'] = ". . --- --- ---";
  80. 	morse_itu['3'] = ". . . --- ---";
  81. 	morse_itu['4'] = ". . . . ---";
  82. 	morse_itu['5'] = ". . . . .";
  83. 	morse_itu['6'] = "--- . . . .";
  84. 	morse_itu['7'] = "--- --- . . .";
  85. 	morse_itu['8'] = "--- --- --- . .";
  86. 	morse_itu['9'] = "--- --- --- --- .";
  87. 	morse_itu['0'] = "--- --- --- --- ---";
  89. 	return 1;
  90. }
  92. int
  93. main(void)
  94. {
  95. 	morse_init();
  96. 	// Use AU defaults
  97. 	struct au_header header = {.offset     = 24,         // no-annotation, in octets
  98. 	                           .length     = 0xFFFFFFFF, // unknown data size
  99. 	                           .encoding   = AU_ENCODING_8B_LPCM,
  100. 	                           .samplerate = 8000, // Hz
  101. 	                           .channels   = 1};
  102. 	int t                   = 0;
  103. 	int tone                = 0;
  104. 	int dur                 = 8000 / 10; // time unit length
  106. 	// fd 1 is stdout
  107. 	write_au_header(1, &header);
  109. 	fputs("ASCII text in, raw audio out", stderr);
  111. 	int c = 0;
  112. 	while((c = getchar()) != -1)
  113. 	{
  114. 		if(isalnum(c))
  115. 		{
  116. 			if(c >= 'a' && c <= 'z')
  117. 			{
  118. 				c = toupper(c);
  119. 			}
  121. 			char *code = morse_itu[c];
  123. 			while(code[0] != '\0')
  124. 			{
  125. 				if(code[0] == '.' || code[0] == '-')
  126. 				{
  127. 					tone = 1;
  128. 				}
  129. 				else
  130. 				{
  131. 					tone = 0;
  132. 				}
  134. 				for(int i = 0; i < dur; i++, t++)
  135. 				{
  136. 					putchar(t++ * tone % 30);
  137. 				}
  139. 				code++;
  140. 			}
  142. 			// letter separation; 3 units
  143. 			for(int i = 0; i < dur * 3; i++, t++)
  144. 			{
  145. 				putchar(t++ * 0 % 30);
  146. 			}
  147. 		}
  148. 		else
  149. 		{
  150. 			// word separation; 7 units
  151. 			for(int i = 0; i < dur * 7; i++, t++)
  152. 			{
  153. 				putchar(t++ * 0 % 30);
  154. 			}
  155. 		}
  156. 	}
  158. 	return 0;
  159. }