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bytemedia

Home to byte-level sounds, images, videos, … git clone https://hacktivis.me/git/bytemedia.git

au.h (1217B)

    

  1. #include <unistd.h> // write()
  2. #include <inttypes.h> // uint32_t
  3. #include <stdio.h> // perror()
  5. struct au_header {
  6. 	uint32_t offset;
  7. 	uint32_t length;
  8. 	uint32_t encoding;
  9. 	uint32_t samplerate;
  10. 	uint32_t channels;
  11. };
  13. enum au_header_encoding {
  14. 	AU_ENCODING_8B_G711_ULAW  = 01,
  15. 	AU_ENCODING_8B_LPCM       = 02,
  16. 	AU_ENCODING_16B_LPCM      = 03,
  17. 	AU_ENCODING_24B_LPCM      = 04,
  18. 	AU_ENCODING_32B_LPCM      = 05,
  19. 	AU_ENCODING_32B_FPCM      = 06,
  20. 	AU_ENCODING_64B_FPCM      = 07,
  22. 	AU_ENCODING_4B_G721_ADPCM = 23,
  24. 	AU_ENCODING_3B_G723_ADPCM = 25,
  26. 	AU_ENCODING_8B_G711_ALAW  = 27,
  27. };
  29. static void
  30. be32enc(void *buf, uint32_t in)
  31. {
  32. 	char *out = (char *)buf;
  34. 	out[0] = (in >> 24) & 0xff;
  35. 	out[1] = (in >> 16) & 0xff;
  36. 	out[2] = (in >> 8) & 0xff;
  37. 	out[3] = (in >> 0) & 0xff;
  38. }
  40. static int
  41. write_au_header(int fd, struct au_header *header)
  42. {
  43. 	char buf[4];
  44. 	uint32_t *value = (uint32_t*)header;
  46. 	if(4 != write(fd, "\x2E\x73\x6E\x64", 4))
  47. 	{
  48. 		perror("write(fd, signature, 4)");
  49. 		return -1;
  50. 	}
  52. 	// 5: number of params in struct au_header
  53. 	for(int i = 0;i<5; i++)
  54. 	{
  55. 		// 32 bits = 4 octets
  56. 		be32enc(buf, *(value+i));
  57. 		if(4 != write(fd, buf, 4))
  58. 		{
  59. 			perror("write(fd, au_header, 4)");
  60. 			return -1;
  61. 		}
  62. 	}
  64. 	return 0;
  65. }