BaseTools: Copy Brotli algorithm 3rd party source code for tool

[mirror_edk2.git] / BaseTools / Source / C / BrotliCompress / enc / quality.h

/* Copyright 2016 Google Inc. All Rights Reserved.\r
\r
   Distributed under MIT license.\r
   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT\r
*/\r
\r
/* Constants and formulas that affect speed-ratio trade-offs and thus define\r
   quality levels. */\r
\r
#ifndef BROTLI_ENC_QUALITY_H_\r
#define BROTLI_ENC_QUALITY_H_\r
\r
#include "./encode.h"\r
\r
#define FAST_ONE_PASS_COMPRESSION_QUALITY 0\r
#define FAST_TWO_PASS_COMPRESSION_QUALITY 1\r
#define ZOPFLIFICATION_QUALITY 10\r
#define HQ_ZOPFLIFICATION_QUALITY 11\r
\r
#define MAX_QUALITY_FOR_STATIC_ENRTOPY_CODES 2\r
#define MIN_QUALITY_FOR_BLOCK_SPLIT 4\r
#define MIN_QUALITY_FOR_OPTIMIZE_HISTOGRAMS 4\r
#define MIN_QUALITY_FOR_EXTENSIVE_REFERENCE_SEARCH 5\r
#define MIN_QUALITY_FOR_CONTEXT_MODELING 5\r
#define MIN_QUALITY_FOR_HQ_CONTEXT_MODELING 7\r
#define MIN_QUALITY_FOR_HQ_BLOCK_SPLITTING 10\r
/* Only for "font" mode. */\r
#define MIN_QUALITY_FOR_RECOMPUTE_DISTANCE_PREFIXES 10\r
\r
/* For quality below MIN_QUALITY_FOR_BLOCK_SPLIT there is no block splitting,\r
   so we buffer at most this much literals and commands. */\r
#define MAX_NUM_DELAYED_SYMBOLS 0x2fff\r
\r
/* Encoding parameters */\r
typedef struct BrotliEncoderParams {\r
  BrotliEncoderMode mode;\r
  int quality;\r
  int lgwin;\r
  int lgblock;\r
} BrotliEncoderParams;\r
\r
/* Returns hashtable size for quality levels 0 and 1. */\r
static BROTLI_INLINE size_t MaxHashTableSize(int quality) {\r
  return quality == FAST_ONE_PASS_COMPRESSION_QUALITY ? 1 << 15 : 1 << 17;\r
}\r
\r
/* The maximum length for which the zopflification uses distinct distances. */\r
#define MAX_ZOPFLI_LEN_QUALITY_10 150\r
#define MAX_ZOPFLI_LEN_QUALITY_11 325\r
\r
static BROTLI_INLINE size_t MaxZopfliLen(const BrotliEncoderParams* params) {\r
  return params->quality <= 10 ?\r
      MAX_ZOPFLI_LEN_QUALITY_10 :\r
      MAX_ZOPFLI_LEN_QUALITY_11;\r
}\r
\r
/* Number of best candidates to evaluate to expand zopfli chain. */\r
static BROTLI_INLINE size_t MaxZopfliCandidates(\r
  const BrotliEncoderParams* params) {\r
  return params->quality <= 10 ? 1 : 5;\r
}\r
\r
static BROTLI_INLINE void SanitizeParams(BrotliEncoderParams* params) {\r
  params->quality = BROTLI_MIN(int, BROTLI_MAX_QUALITY,\r
      BROTLI_MAX(int, BROTLI_MIN_QUALITY, params->quality));\r
  if (params->lgwin < kBrotliMinWindowBits) {\r
    params->lgwin = kBrotliMinWindowBits;\r
  } else if (params->lgwin > kBrotliMaxWindowBits) {\r
    params->lgwin = kBrotliMaxWindowBits;\r
  }\r
}\r
\r
/* Returns optimized lg_block value. */\r
static BROTLI_INLINE int ComputeLgBlock(const BrotliEncoderParams* params) {\r
  int lgblock = params->lgblock;\r
  if (params->quality == FAST_ONE_PASS_COMPRESSION_QUALITY ||\r
      params->quality == FAST_TWO_PASS_COMPRESSION_QUALITY) {\r
    lgblock = params->lgwin;\r
  } else if (params->quality < MIN_QUALITY_FOR_BLOCK_SPLIT) {\r
    lgblock = 14;\r
  } else if (lgblock == 0) {\r
    lgblock = 16;\r
    if (params->quality >= 9 && params->lgwin > lgblock) {\r
      lgblock = BROTLI_MIN(int, 18, params->lgwin);\r
    }\r
  } else {\r
    lgblock = BROTLI_MIN(int, kBrotliMaxInputBlockBits,\r
        BROTLI_MAX(int, kBrotliMinInputBlockBits, lgblock));\r
  }\r
  return lgblock;\r
}\r
\r
/* Returns log2 of the size of main ring buffer area.\r
   Allocate at least lgwin + 1 bits for the ring buffer so that the newly\r
   added block fits there completely and we still get lgwin bits and at least\r
   read_block_size_bits + 1 bits because the copy tail length needs to be\r
   smaller than ringbuffer size. */\r
static BROTLI_INLINE int ComputeRbBits(const BrotliEncoderParams* params) {\r
  return 1 + BROTLI_MAX(int, params->lgwin, params->lgblock);\r
}\r
\r
static BROTLI_INLINE size_t MaxMetablockSize(\r
    const BrotliEncoderParams* params) {\r
  int bits = BROTLI_MIN(int, ComputeRbBits(params), kBrotliMaxInputBlockBits);\r
  return (size_t)1 << bits;\r
}\r
\r
/* When searching for backward references and have not seen matches for a long\r
   time, we can skip some match lookups. Unsuccessful match lookups are very\r
   expensive and this kind of a heuristic speeds up compression quite a lot.\r
   At first 8 byte strides are taken and every second byte is put to hasher.\r
   After 4x more literals stride by 16 bytes, every put 4-th byte to hasher.\r
   Applied only to qualities 2 to 9. */\r
static BROTLI_INLINE size_t LiteralSpreeLengthForSparseSearch(\r
    const BrotliEncoderParams* params) {\r
  return params->quality < 9 ? 64 : 512;\r
}\r
\r
static BROTLI_INLINE int ChooseHasher(const BrotliEncoderParams* params) {\r
  if (params->quality > 9) {\r
    return 10;\r
  } else if (params->quality < 5) {\r
    return params->quality;\r
  } else if (params->lgwin <= 16) {\r
    return params->quality < 7 ? 40 : params->quality < 9 ? 41 : 42;\r
  }\r
  return params->quality;\r
}\r
\r
#endif  /* BROTLI_ENC_QUALITY_H_ */\r