1 /* Copyright 2015 Google Inc. All Rights Reserved. 2 3 Distributed under MIT license. 4 See file LICENSE for detail or copy at https://opensource.org/licenses/MIT 5 */ 6 7 /* Algorithms for distributing the literals and commands of a metablock between 8 block types and contexts. */ 9 10 #ifndef BROTLI_ENC_METABLOCK_H_ 11 #define BROTLI_ENC_METABLOCK_H_ 12 13 #include <brotli/types.h> 14 #include "./block_splitter.h" 15 #include "./command.h" 16 #include "./context.h" 17 #include "./histogram.h" 18 #include "./memory.h" 19 #include "./port.h" 20 #include "./quality.h" 21 22 #if defined(__cplusplus) || defined(c_plusplus) 23 extern "C" { 24 #endif 25 26 typedef struct MetaBlockSplit { 27 BlockSplit literal_split; 28 BlockSplit command_split; 29 BlockSplit distance_split; 30 uint32_t* literal_context_map; 31 size_t literal_context_map_size; 32 uint32_t* distance_context_map; 33 size_t distance_context_map_size; 34 HistogramLiteral* literal_histograms; 35 size_t literal_histograms_size; 36 HistogramCommand* command_histograms; 37 size_t command_histograms_size; 38 HistogramDistance* distance_histograms; 39 size_t distance_histograms_size; 40 } MetaBlockSplit; 41 42 static BROTLI_INLINE void InitMetaBlockSplit(MetaBlockSplit* mb) { 43 BrotliInitBlockSplit(&mb->literal_split); 44 BrotliInitBlockSplit(&mb->command_split); 45 BrotliInitBlockSplit(&mb->distance_split); 46 mb->literal_context_map = 0; 47 mb->literal_context_map_size = 0; 48 mb->distance_context_map = 0; 49 mb->distance_context_map_size = 0; 50 mb->literal_histograms = 0; 51 mb->literal_histograms_size = 0; 52 mb->command_histograms = 0; 53 mb->command_histograms_size = 0; 54 mb->distance_histograms = 0; 55 mb->distance_histograms_size = 0; 56 } 57 58 static BROTLI_INLINE void DestroyMetaBlockSplit( 59 MemoryManager* m, MetaBlockSplit* mb) { 60 BrotliDestroyBlockSplit(m, &mb->literal_split); 61 BrotliDestroyBlockSplit(m, &mb->command_split); 62 BrotliDestroyBlockSplit(m, &mb->distance_split); 63 BROTLI_FREE(m, mb->literal_context_map); 64 BROTLI_FREE(m, mb->distance_context_map); 65 BROTLI_FREE(m, mb->literal_histograms); 66 BROTLI_FREE(m, mb->command_histograms); 67 BROTLI_FREE(m, mb->distance_histograms); 68 } 69 70 /* Uses the slow shortest-path block splitter and does context clustering. */ 71 BROTLI_INTERNAL void BrotliBuildMetaBlock(MemoryManager* m, 72 const uint8_t* ringbuffer, 73 const size_t pos, 74 const size_t mask, 75 const BrotliEncoderParams* params, 76 uint8_t prev_byte, 77 uint8_t prev_byte2, 78 const Command* cmds, 79 size_t num_commands, 80 ContextType literal_context_mode, 81 MetaBlockSplit* mb); 82 83 /* Uses a fast greedy block splitter that tries to merge current block with the 84 last or the second last block and uses a static context clustering which 85 is the same for all block types. */ 86 BROTLI_INTERNAL void BrotliBuildMetaBlockGreedy( 87 MemoryManager* m, const uint8_t* ringbuffer, size_t pos, size_t mask, 88 uint8_t prev_byte, uint8_t prev_byte2, ContextType literal_context_mode, 89 size_t num_contexts, const uint32_t* static_context_map, 90 const Command* commands, size_t n_commands, MetaBlockSplit* mb); 91 92 BROTLI_INTERNAL void BrotliOptimizeHistograms(size_t num_direct_distance_codes, 93 size_t distance_postfix_bits, 94 MetaBlockSplit* mb); 95 96 #if defined(__cplusplus) || defined(c_plusplus) 97 } /* extern "C" */ 98 #endif 99 100 #endif /* BROTLI_ENC_METABLOCK_H_ */ 101
