base64.c 1.5 KB

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  1. /*
  2. * This file is part of FFmpeg.
  3. *
  4. * FFmpeg is free software; you can redistribute it and/or
  5. * modify it under the terms of the GNU Lesser General Public
  6. * License as published by the Free Software Foundation; either
  7. * version 2.1 of the License, or (at your option) any later version.
  8. *
  9. * FFmpeg is distributed in the hope that it will be useful,
  10. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  12. * Lesser General Public License for more details.
  13. *
  14. * You should have received a copy of the GNU Lesser General Public
  15. * License along with FFmpeg; if not, write to the Free Software
  16. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17. */
  18. /*
  19. * Based on libavutil/base64.c
  20. */
  21. #include <stdio.h>
  22. int main(void)
  23. {
  24. static const char b64[] =
  25. "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  26. unsigned i_bits = 0;
  27. int i_shift = 0;
  28. int out_len = 0;
  29. int in;
  30. #define putb64() do { \
  31. putchar(b64[(i_bits << 6 >> i_shift) & 0x3f]); \
  32. out_len++; \
  33. i_shift -= 6; \
  34. } while (0)
  35. while ((in = getchar()) != EOF) {
  36. i_bits = (i_bits << 8) + in;
  37. i_shift += 8;
  38. while (i_shift > 6)
  39. putb64();
  40. }
  41. while (i_shift > 0)
  42. putb64();
  43. while (out_len++ & 3)
  44. putchar('=');
  45. putchar('\n');
  46. return 0;
  47. }