godot/drivers/webpold/utils/huffman_encode.h
Juan Linietsky da113fe40d -Upgraded webp to a MUCH newer version. Hoping it fixes some bugs in the process. Keeping old version just in case for now.
-Added ability to convert xml and tscn scenes to binary on export, makes loading of larger scenes faster
2015-12-04 10:18:28 -03:00

48 lines
1.6 KiB
C

// Copyright 2011 Google Inc. All Rights Reserved.
//
// This code is licensed under the same terms as WebM:
// Software License Agreement: http://www.webmproject.org/license/software/
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// Author: Jyrki Alakuijala (jyrki@google.com)
//
// Entropy encoding (Huffman) for webp lossless
#ifndef WEBP_UTILS_HUFFMAN_ENCODE_H_
#define WEBP_UTILS_HUFFMAN_ENCODE_H_
#include "../types.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
// Struct for holding the tree header in coded form.
typedef struct {
uint8_t code; // value (0..15) or escape code (16,17,18)
uint8_t extra_bits; // extra bits for escape codes
} HuffmanTreeToken;
// Struct to represent the tree codes (depth and bits array).
typedef struct {
int num_symbols; // Number of symbols.
uint8_t* code_lengths; // Code lengths of the symbols.
uint16_t* codes; // Symbol Codes.
} HuffmanTreeCode;
// Turn the Huffman tree into a token sequence.
// Returns the number of tokens used.
int VP8LCreateCompressedHuffmanTree(const HuffmanTreeCode* const tree,
HuffmanTreeToken* tokens, int max_tokens);
// Create an optimized tree, and tokenize it.
int VP8LCreateHuffmanTree(int* const histogram, int tree_depth_limit,
HuffmanTreeCode* const tree);
#if defined(__cplusplus) || defined(c_plusplus)
}
#endif
#endif // WEBP_UTILS_HUFFMAN_ENCODE_H_