添加不依赖bytearray的版本

This commit is contained in:
andy
2023-11-22 23:05:01 +08:00
parent f93b275e60
commit c475f0e4f0
5 changed files with 489 additions and 1 deletions

5
.gitignore vendored Normal file
View File

@@ -0,0 +1,5 @@
.vs/
*.exe

View File

@@ -1,5 +1,6 @@
{
"files.associations": {
"coder_lib.h": "c"
"coder_lib.h": "c",
"huffman_.h": "c"
}
}

View File

@@ -8,3 +8,5 @@ gcc hello.c -o hello
2023.11.22
huffman数据压缩算法验证成功
2023.11.22
移除huffman对 bytearray的依赖

461
huffman_.c Normal file
View File

@@ -0,0 +1,461 @@
#include "stdlib.h"
#include "stdio.h"
#include "string.h"
#include "huffman_.h"
// huffman编码的实现
#define DBG_WARN printf
#define DBG_LOG printf
typedef struct _huff_tree{
uint8_t data;
uint8_t pos;// 位置左为1右为0
uint16_t count;
struct _huff_tree *parant;
struct _huff_tree *left;
struct _huff_tree *right;
}huff_tree;
typedef struct{
huff_tree *tree;
int index_table_index;
huff_tree *index_table[256];
uint16_t count_table[256];
uint8_t *out;
int out_len;
uint8_t *in;
int in_len;
int in_bit_count;
int arr_bit_index;
}huffman_def;
static int hm_calc_value_of_tree(huff_tree *t);
static int hm_calc_deep_of_child(huff_tree* t);
// 按出现频次排序
static void hm_sort_index_table(huff_tree **table,int num)
{
for(int i=0;i<num;i++)
{
huff_tree *item=table[i];
for (int j=i;j<num;j++)
{
if(hm_calc_value_of_tree(table[j])>hm_calc_value_of_tree(item))
{
table[i]=table[j];
table[j]=item;
item=table[i];
}
}
}
}
// 打印index_table
static void hm_index_table_print(huffman_def *h){
DBG_LOG("-----index_table-----\n");
for(int i=0;i<h->index_table_index;i++){
DBG_LOG("index:%d,data:%02x,count:%d\n",i,h->index_table[i]->data,h->index_table[i]->count);
}
}
// 打印数据的编码
static void hm_data_code_print(huffman_def *h){
huff_tree *t;
DBG_LOG("------data code------\n");
for(int i=0;i<h->index_table_index;i++){
t=h->index_table[i];
DBG_LOG("%c:",t->data);
while(t->parant){
DBG_LOG("%d",t->pos);
t=t->parant;
}
DBG_LOG("\n");
}
}
static void hm_calc_count(huffman_def *h,const uint8_t *d,const int d_len)
{
int num = d_len;
int index;
memset(h->count_table,0,256);
// DBG_LOG("calc count_table\n");
for(int i=0;i<num;i++)
{
h->count_table[d[i]]++;
}
// DBG_LOG("calc index_table\n");
for(int i=0;i<256;i++)
{
if(h->count_table[i]>0){
index=h->index_table_index;
h->index_table[index]=calloc(1,sizeof(huff_tree));
h->index_table[index]->count=h->count_table[i];
h->index_table[index]->data=i;
h->index_table_index++;
}
}
// DBG_LOG("sort index_table\n");
hm_sort_index_table(h->index_table,h->index_table_index);
// hm_index_table_print(h);
}
// 计算编码后的长度
// 需要先计算index_table和生成huffman树
static int hm_calc_encode_len(huffman_def* h)
{
// index_table_len(1byte)+index_data(index_table_len bytes)
int sum =1+ h->index_table_index;
int bit_count = 0;
huff_tree* t;
for (int i = 0; i < h->index_table_index; i++) {
// 计数占用的字节数
t = h->index_table[i];
sum += t->count/255+1;
// 压缩后占用的bit数
bit_count += hm_calc_deep_of_child(t) * t->count;
}
// 补零数目字节
sum += 1;
sum += (bit_count + 7) / 8;
DBG_LOG("data len for encode:%d\n", sum);
return sum;
}
// 计算树的值
static int hm_calc_value_of_tree(huff_tree *t)
{
int sum=0;
if(t->left&&t->right)
sum=hm_calc_value_of_tree(t->left)+hm_calc_value_of_tree(t->right);
else
sum=t->count;
// DBG_LOG("tree sum:%d\n",sum);
return sum;
}
// 计算子节点的深度
static int hm_calc_deep_of_child(huff_tree* t)
{
int deep = 0;
while (t->parant) {
deep++;
t = t->parant;
}
return deep;
}
// 打印huffman树
static void hm_tree_print(huff_tree *t)
{
if(t->left&&t->right){
DBG_LOG("point:,count:%d\n",hm_calc_value_of_tree(t));
hm_tree_print(t->left);
hm_tree_print(t->right);
}else{
DBG_LOG("data:%d,count:%d\n",t->data,t->count);
}
}
// 建立huffman树
static void hm_creat_tree(huffman_def *h)
{
int tail=h->index_table_index;
huff_tree *sub1,*sub2;
huff_tree **table=calloc(tail,sizeof(huff_tree *));
for(int i=0;i<tail;i++){
table[i]=h->index_table[i];
}
while(tail>1){
huff_tree *temp;
sub1=table[tail-1];
sub2=table[tail-2];
// 大在左,小在右
temp=calloc(1,sizeof(huff_tree));
sub1->parant=temp;
sub2->parant=temp;
// 左为1右为0
if(hm_calc_value_of_tree(sub1)>hm_calc_value_of_tree(sub2)){
temp->left=sub1;
sub1->pos=1;
temp->right=sub2;
sub2->pos=0;
}else{
temp->left=sub2;
sub2->pos=1;
temp->right=sub1;
sub1->pos=0;
}
table[tail-2]=temp;
tail--;
hm_sort_index_table(table,tail);
// DBG_LOG("-----table-----\n");
// for(int i=0;i<tail;i++){
// DBG_LOG("index:%d,count:%d\n",i,hm_calc_value_of_tree(table[i]));
// }
}
h->tree=table[0];
free(table);
}
// 删除树
static void hm_del_tree(huff_tree *t)
{
if(t->left&&t->right){
hm_del_tree(t->left);
hm_del_tree(t->right);
}
free(t);
}
// 数据中添加一个bit
static void hm_add_bit(uint8_t *d,int *d_len,int bit,int *index)
{
if(*index<(*d_len )*8){
uint8_t c = d[*d_len - 1];
c|=bit<<(*index%8);
d[*d_len - 1] = c;
}else{
d[*d_len] = bit;
(*d_len)++;
}
(*index)++;
}
// 根据数据添加bit
static int hm_encode_byte(huffman_def *h,uint8_t d)
{
huff_tree *t=0;
// 这里默认一定能找到对应的值
for(int i=0;i<h->index_table_index;i++)
{
t=h->index_table[i];
if(t->data==d)
break;
}
if(t->data!=d){
DBG_WARN("can not encode.\n");
exit(-1);
}
while(t->parant){
hm_add_bit(h->out,&h->out_len,t->pos,&h->arr_bit_index);
t=t->parant;
}
// char *str=arr_string(h->out);
// DBG_LOG("index:%d,out data:%s\n",h->arr_bit_index,str);
// free(str);
return 0;
}
// 生成索引
static int hm_creat_index_table(huffman_def *h,uint8_t *data,int *data_len)
{
int temp;
int diff;
int temp_num;
data[*data_len] = h->index_table_index; (*data_len)++;
hm_index_table_print(h);
for(int i=0;i<h->index_table_index;i++)
{
data[*data_len] = h->index_table[i]->data; (*data_len)++;
temp=h->index_table[i]->count;
temp_num = temp / 255 + 1;
for (int i = 0; i < temp_num; i++) {
if (i < temp_num - 1) {
data[*data_len] = 255; (*data_len)++;
}
else {
data[*data_len] = temp % 255; (*data_len)++;
}
}
}
// 填充0个数
temp=8-(h->arr_bit_index%8);
//DBG_LOG("fill with 0 by:%d\n", temp);
data[*data_len] = temp; (*data_len)++;
return 0;
}
// huffman编码
/*
压缩后数据格式
data[0]:索引表长度
data[1~n]:索引表,每个索引由值(1byte)和频次(1byte,小于255)(2byte,大于等于255,频次由两个字节相加)
data[n+1]:数据中填充0个数
data[n+2~m]:压缩后的数据
*/
int hm_encode(const uint8_t* in, const int in_len, uint8_t** out, int* out_len)
{
int input_len = in_len;
int output_len=0;
int output_index = 0;
huffman_def *h=calloc(1,sizeof(huffman_def));
hm_calc_count(h,in, input_len);
hm_creat_tree(h);
output_len = hm_calc_encode_len(h);
(*out) = calloc(output_len + 1, sizeof(uint8_t));
hm_creat_index_table(h, *out, &output_index);
DBG_LOG("output_len=%d\n", output_index);
h->out = &(*out)[output_index];
for(int i=0;i<input_len;i++)
{
hm_encode_byte(h,in[i]);
}
DBG_LOG("bitcount:%d\n", h->arr_bit_index);
(*out)[output_index-1] = h->out_len*8- h->arr_bit_index;
DBG_LOG("fill with 0 by:%d\n", (*out)[output_index - 1]);
(*out_len) = output_len;
hm_del_tree(h->tree);
DBG_LOG("lenth_in:%d,length_encode:%d\n",input_len, output_len);
free(h);
return 0;
}
// 读取编码表,返回数据开始的位置
static int hm_unpack_count(huffman_def *h,const uint8_t *d,int d_len)
{
int num = d[0];
int index=1;
uint8_t temp;
for(int i=0;i<num;i++)
{
h->index_table[i]=calloc(1,sizeof(huff_tree));
h->index_table[i]->data=d[index];index++;
do{
temp= d[index];index++;
h->index_table[i]->count+=temp;
}while(temp==0xff);
h->index_table_index++;
}
temp= d[index];index++;
h->in_bit_count=(d_len -index)*8-temp;
h->in=&d[index];
// hm_index_table_print(h);
printf("bitcount:%d,\n",h->in_bit_count);
return index;
}
// 获取指定index的bit值
static inline int hm_get_bit(const uint8_t *d,int index)
{
uint8_t t=d[index/8];
return t&(1<<(index%8))?1:0;
}
// 对比树节点匹配返回bit数不匹配返回0
static inline int hm_cmp_bits(huffman_def *h,huff_tree *t)
{
int count=0;
// DBG_LOG("tree pos:",t->pos);
while(t){
// DBG_LOG("%d",t->pos);
if(hm_get_bit(h->in,h->arr_bit_index+count)!=t->pos){
// DBG_LOG(" |failed\n");
return 0;
}
else{
count++;
t=t->parant;
}
}
h->arr_bit_index+=count;
// DBG_LOG(" |ok,\n");
return count;
}
static uint8_t hm_decode_byte(huffman_def *h)
{
huff_tree *t=h->tree;
int bit;
// DBG_LOG("decode:");
while(t->left&&t->right){
bit=hm_get_bit(h->in,h->arr_bit_index-1);
// DBG_LOG("%d",bit);
if(bit==t->left->pos)
t=t->left;
else
t=t->right;
h->arr_bit_index--;
}
// DBG_LOG(" | decode byte:%c\n",t->data);
return t->data;
}
static int hm_calc_decode_len(huffman_def *h)
{
int sum=0;
for(int i=0;i<h->index_table_index;i++){
sum+=h->index_table[i]->count;
}
DBG_LOG("data len for decode:%d\n",sum);
return sum;
}
// huffman解码
/*
*/
int hm_decode(const uint8_t* in, const int in_len, uint8_t** out, int* out_len)
{
int decode_len,decode_index;
uint8_t *decode_data=0;
uint8_t c;
huffman_def *h=calloc(1,sizeof(huffman_def));
if (h == 0) {
return -1;
}
hm_unpack_count(h,in,in_len);
hm_creat_tree(h);
// hm_data_code_print(h);
// hm_tree_print(h->tree);
decode_len=hm_calc_decode_len(h);
decode_index=decode_len;
decode_data=calloc(decode_len+1,sizeof(uint8_t));
h->arr_bit_index=h->in_bit_count;
while(decode_index >0){
c=hm_decode_byte(h);
decode_data[decode_index-1]=c;
decode_index--;
}
hm_del_tree(h->tree);
free(h);
(*out) = decode_data;
(*out_len) = decode_len;
return 0;
}

19
huffman_.h Normal file
View File

@@ -0,0 +1,19 @@
#ifndef huffman_h__
#define huffman_h__
#include "stdint.h"
// huffman编码的实现
int hm_encode(const uint8_t *in,const int in_len,uint8_t **out,int *out_len);
int hm_decode(const uint8_t* in, const int in_len, uint8_t** out, int* out_len);
#endif