notaz.gp2x.de / pcsx_rearmed.git / blame
| Commit | Line | Data |
|---|---|---|
| 3719602c PC |
1 | /* license:BSD-3-Clause |
| 2 | * copyright-holders:Aaron Giles | |
| 3 | *************************************************************************** | |
| 4 | ||
| 5 | huffman.h | |
| 6 | ||
| 7 | Static Huffman compression and decompression helpers. | |
| 8 | ||
| 9 | ***************************************************************************/ | |
| 10 | ||
| 11 | #pragma once | |
| 12 | ||
| 13 | #ifndef __HUFFMAN_H__ | |
| 14 | #define __HUFFMAN_H__ | |
| 15 | ||
| 16 | #include "bitstream.h" | |
| 17 | ||
| 18 | /*************************************************************************** | |
| 19 | * CONSTANTS | |
| 20 | *************************************************************************** | |
| 21 | */ | |
| 22 | ||
| 23 | enum huffman_error | |
| 24 | { | |
| 25 | HUFFERR_NONE = 0, | |
| 26 | HUFFERR_TOO_MANY_BITS, | |
| 27 | HUFFERR_INVALID_DATA, | |
| 28 | HUFFERR_INPUT_BUFFER_TOO_SMALL, | |
| 29 | HUFFERR_OUTPUT_BUFFER_TOO_SMALL, | |
| 30 | HUFFERR_INTERNAL_INCONSISTENCY, | |
| 31 | HUFFERR_TOO_MANY_CONTEXTS | |
| 32 | }; | |
| 33 | ||
| 34 | /*************************************************************************** | |
| 35 | * TYPE DEFINITIONS | |
| 36 | *************************************************************************** | |
| 37 | */ | |
| 38 | ||
| 39 | typedef uint16_t lookup_value; | |
| 40 | ||
| 41 | /* a node in the huffman tree */ | |
| 42 | struct node_t | |
| 43 | { | |
| 44 | struct node_t* parent; /* pointer to parent node */ | |
| 45 | uint32_t count; /* number of hits on this node */ | |
| 46 | uint32_t weight; /* assigned weight of this node */ | |
| 47 | uint32_t bits; /* bits used to encode the node */ | |
| 48 | uint8_t numbits; /* number of bits needed for this node */ | |
| 49 | }; | |
| 50 | ||
| 51 | /* ======================> huffman_context_base */ | |
| 52 | ||
| 53 | /* context class for decoding */ | |
| 54 | struct huffman_decoder | |
| 55 | { | |
| 56 | /* internal state */ | |
| 57 | uint32_t numcodes; /* number of total codes being processed */ | |
| 58 | uint8_t maxbits; /* maximum bits per code */ | |
| 59 | uint8_t prevdata; /* value of the previous data (for delta-RLE encoding) */ | |
| 60 | int rleremaining; /* number of RLE bytes remaining (for delta-RLE encoding) */ | |
| 61 | lookup_value * lookup; /* pointer to the lookup table */ | |
| 62 | struct node_t * huffnode; /* array of nodes */ | |
| 63 | uint32_t * datahisto; /* histogram of data values */ | |
| 64 | ||
| 65 | /* array versions of the info we need */ | |
| 66 | #if 0 | |
| 67 | node_t* huffnode_array; /* [_NumCodes]; */ | |
| 68 | lookup_value* lookup_array; /* [1 << _MaxBits]; */ | |
| 69 | #endif | |
| 70 | }; | |
| 71 | ||
| 72 | /* ======================> huffman_decoder */ | |
| 73 | ||
| 74 | struct huffman_decoder* create_huffman_decoder(int numcodes, int maxbits); | |
| 75 | void delete_huffman_decoder(struct huffman_decoder* decoder); | |
| 76 | ||
| 77 | /* single item operations */ | |
| 78 | uint32_t huffman_decode_one(struct huffman_decoder* decoder, struct bitstream* bitbuf); | |
| 79 | ||
| 80 | enum huffman_error huffman_import_tree_rle(struct huffman_decoder* decoder, struct bitstream* bitbuf); | |
| 81 | enum huffman_error huffman_import_tree_huffman(struct huffman_decoder* decoder, struct bitstream* bitbuf); | |
| 82 | ||
| 83 | int huffman_build_tree(struct huffman_decoder* decoder, uint32_t totaldata, uint32_t totalweight); | |
| 84 | enum huffman_error huffman_assign_canonical_codes(struct huffman_decoder* decoder); | |
| 85 | enum huffman_error huffman_compute_tree_from_histo(struct huffman_decoder* decoder); | |
| 86 | ||
| 87 | void huffman_build_lookup_table(struct huffman_decoder* decoder); | |
| 88 | ||
| 89 | #endif |