constants.h.3 1.7 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647
  1. .TH "constants.h" 3 "August 2021" "Brotli" \" -*- nroff -*-
  2. .ad l
  3. .nh
  4. .SH NAME
  5. constants.h \- Common constants used in decoder and encoder API\&.
  6. .SH SYNOPSIS
  7. .br
  8. .PP
  9. .SS "Macros"
  10. .in +1c
  11. .ti -1c
  12. .RI "#define \fBBROTLI_LARGE_MAX_DISTANCE_BITS\fP 62U"
  13. .br
  14. .RI "\fIThe theoretical maximum number of distance bits specified for large window brotli, for 64-bit encoders and decoders\&. \fP"
  15. .ti -1c
  16. .RI "#define \fBBROTLI_LARGE_MAX_WBITS\fP 30"
  17. .br
  18. .RI "\fIThe maximum supported large brotli window bits by the encoder and decoder\&. \fP"
  19. .ti -1c
  20. .RI "#define \fBBROTLI_MAX_NPOSTFIX\fP 3"
  21. .br
  22. .RI "\fIMaximal number of 'postfix' bits\&. \fP"
  23. .in -1c
  24. .SH "Detailed Description"
  25. .PP
  26. Common constants used in decoder and encoder API\&.
  27. .SH "Macro Definition Documentation"
  28. .PP
  29. .SS "#define BROTLI_LARGE_MAX_DISTANCE_BITS 62U"
  30. .PP
  31. The theoretical maximum number of distance bits specified for large window brotli, for 64-bit encoders and decoders\&. Even when in practice 32-bit encoders and decoders only support up to 30 max distance bits, the value is set to 62 because it affects the large window brotli file format\&. Specifically, it affects the encoding of simple huffman tree for distances, see Specification RFC 7932 chapter 3\&.4\&.
  32. .SS "#define BROTLI_LARGE_MAX_WBITS 30"
  33. .PP
  34. The maximum supported large brotli window bits by the encoder and decoder\&. Large window brotli allows up to 62 bits, however the current encoder and decoder, designed for 32-bit integers, only support up to 30 bits maximum\&.
  35. .SS "#define BROTLI_MAX_NPOSTFIX 3"
  36. .PP
  37. Maximal number of 'postfix' bits\&. Number of 'postfix' bits is stored as 2 bits in meta-block header\&.
  38. .SH "Author"
  39. .PP
  40. Generated automatically by Doxygen for Brotli from the source code\&.