X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=BaseTools%2FSource%2FC%2FBrotliCompress%2Fenc%2Fquality.h;fp=BaseTools%2FSource%2FC%2FBrotliCompress%2Fenc%2Fquality.h;h=a4969ad85e821831ce22e72707134ccbc3c7be08;hb=11b7501adcf8af81b3a31702eb4daa799d5f4096;hp=0000000000000000000000000000000000000000;hpb=841b259062d5f71be41c7358217d3945038a37bf;p=mirror_edk2.git diff --git a/BaseTools/Source/C/BrotliCompress/enc/quality.h b/BaseTools/Source/C/BrotliCompress/enc/quality.h new file mode 100644 index 0000000000..a4969ad85e --- /dev/null +++ b/BaseTools/Source/C/BrotliCompress/enc/quality.h @@ -0,0 +1,130 @@ +/* Copyright 2016 Google Inc. All Rights Reserved. + + Distributed under MIT license. + See file LICENSE for detail or copy at https://opensource.org/licenses/MIT +*/ + +/* Constants and formulas that affect speed-ratio trade-offs and thus define + quality levels. */ + +#ifndef BROTLI_ENC_QUALITY_H_ +#define BROTLI_ENC_QUALITY_H_ + +#include "./encode.h" + +#define FAST_ONE_PASS_COMPRESSION_QUALITY 0 +#define FAST_TWO_PASS_COMPRESSION_QUALITY 1 +#define ZOPFLIFICATION_QUALITY 10 +#define HQ_ZOPFLIFICATION_QUALITY 11 + +#define MAX_QUALITY_FOR_STATIC_ENRTOPY_CODES 2 +#define MIN_QUALITY_FOR_BLOCK_SPLIT 4 +#define MIN_QUALITY_FOR_OPTIMIZE_HISTOGRAMS 4 +#define MIN_QUALITY_FOR_EXTENSIVE_REFERENCE_SEARCH 5 +#define MIN_QUALITY_FOR_CONTEXT_MODELING 5 +#define MIN_QUALITY_FOR_HQ_CONTEXT_MODELING 7 +#define MIN_QUALITY_FOR_HQ_BLOCK_SPLITTING 10 +/* Only for "font" mode. */ +#define MIN_QUALITY_FOR_RECOMPUTE_DISTANCE_PREFIXES 10 + +/* For quality below MIN_QUALITY_FOR_BLOCK_SPLIT there is no block splitting, + so we buffer at most this much literals and commands. */ +#define MAX_NUM_DELAYED_SYMBOLS 0x2fff + +/* Encoding parameters */ +typedef struct BrotliEncoderParams { + BrotliEncoderMode mode; + int quality; + int lgwin; + int lgblock; +} BrotliEncoderParams; + +/* Returns hashtable size for quality levels 0 and 1. */ +static BROTLI_INLINE size_t MaxHashTableSize(int quality) { + return quality == FAST_ONE_PASS_COMPRESSION_QUALITY ? 1 << 15 : 1 << 17; +} + +/* The maximum length for which the zopflification uses distinct distances. */ +#define MAX_ZOPFLI_LEN_QUALITY_10 150 +#define MAX_ZOPFLI_LEN_QUALITY_11 325 + +static BROTLI_INLINE size_t MaxZopfliLen(const BrotliEncoderParams* params) { + return params->quality <= 10 ? + MAX_ZOPFLI_LEN_QUALITY_10 : + MAX_ZOPFLI_LEN_QUALITY_11; +} + +/* Number of best candidates to evaluate to expand zopfli chain. */ +static BROTLI_INLINE size_t MaxZopfliCandidates( + const BrotliEncoderParams* params) { + return params->quality <= 10 ? 1 : 5; +} + +static BROTLI_INLINE void SanitizeParams(BrotliEncoderParams* params) { + params->quality = BROTLI_MIN(int, BROTLI_MAX_QUALITY, + BROTLI_MAX(int, BROTLI_MIN_QUALITY, params->quality)); + if (params->lgwin < kBrotliMinWindowBits) { + params->lgwin = kBrotliMinWindowBits; + } else if (params->lgwin > kBrotliMaxWindowBits) { + params->lgwin = kBrotliMaxWindowBits; + } +} + +/* Returns optimized lg_block value. */ +static BROTLI_INLINE int ComputeLgBlock(const BrotliEncoderParams* params) { + int lgblock = params->lgblock; + if (params->quality == FAST_ONE_PASS_COMPRESSION_QUALITY || + params->quality == FAST_TWO_PASS_COMPRESSION_QUALITY) { + lgblock = params->lgwin; + } else if (params->quality < MIN_QUALITY_FOR_BLOCK_SPLIT) { + lgblock = 14; + } else if (lgblock == 0) { + lgblock = 16; + if (params->quality >= 9 && params->lgwin > lgblock) { + lgblock = BROTLI_MIN(int, 18, params->lgwin); + } + } else { + lgblock = BROTLI_MIN(int, kBrotliMaxInputBlockBits, + BROTLI_MAX(int, kBrotliMinInputBlockBits, lgblock)); + } + return lgblock; +} + +/* Returns log2 of the size of main ring buffer area. + Allocate at least lgwin + 1 bits for the ring buffer so that the newly + added block fits there completely and we still get lgwin bits and at least + read_block_size_bits + 1 bits because the copy tail length needs to be + smaller than ringbuffer size. */ +static BROTLI_INLINE int ComputeRbBits(const BrotliEncoderParams* params) { + return 1 + BROTLI_MAX(int, params->lgwin, params->lgblock); +} + +static BROTLI_INLINE size_t MaxMetablockSize( + const BrotliEncoderParams* params) { + int bits = BROTLI_MIN(int, ComputeRbBits(params), kBrotliMaxInputBlockBits); + return (size_t)1 << bits; +} + +/* When searching for backward references and have not seen matches for a long + time, we can skip some match lookups. Unsuccessful match lookups are very + expensive and this kind of a heuristic speeds up compression quite a lot. + At first 8 byte strides are taken and every second byte is put to hasher. + After 4x more literals stride by 16 bytes, every put 4-th byte to hasher. + Applied only to qualities 2 to 9. */ +static BROTLI_INLINE size_t LiteralSpreeLengthForSparseSearch( + const BrotliEncoderParams* params) { + return params->quality < 9 ? 64 : 512; +} + +static BROTLI_INLINE int ChooseHasher(const BrotliEncoderParams* params) { + if (params->quality > 9) { + return 10; + } else if (params->quality < 5) { + return params->quality; + } else if (params->lgwin <= 16) { + return params->quality < 7 ? 40 : params->quality < 9 ? 41 : 42; + } + return params->quality; +} + +#endif /* BROTLI_ENC_QUALITY_H_ */