dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-14 21:09:55 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

~20% faster lossless decoding

Browse Source 
We use help from small LUTs for Huffman decoding.

Change-Id: I58db4ecd37282822094519f2aa14cf544beba975
This commit is contained in:
skal
2013-06-20 09:41:29 +02:00
parent 313d853fa9
commit 24cc307ae3
3 changed files with 36 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
src/utils/huffman.h
View File

@ -28,8 +28,14 @@ typedef struct {
} HuffmanTreeNode;
// Huffman Tree.
#define HUFF_LUT_BITS 7
#define HUFF_LUT (1U << HUFF_LUT_BITS)
typedef struct HuffmanTree HuffmanTree;
struct HuffmanTree {
// Fast lookup for short bit lengths.
uint8_t lut_bits_[HUFF_LUT];
int lut_symbol_[HUFF_LUT];
// Complete tree for lookups.
HuffmanTreeNode* root_; // all the nodes, starting at root.
int max_nodes_; // max number of nodes
int num_nodes_; // number of currently occupied nodes