35 lines
954 B
C
35 lines
954 B
C
#include "compress.h"
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uint32_t compress_rle(void* data, uint32_t size, uint8_t *dest) {
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if (size < 1) return 0;
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uint32_t total_size = 0;
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uint8_t *buf = (uint8_t*)data;
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uint8_t byte = buf[0];
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uint16_t occurences = 1;
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for (uint32_t i = 1; i <= size; i += 1){
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if (buf[i] != byte || i == size) {
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*(uint16_t*)dest = occurences; dest += 2;
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*dest++ = byte;
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byte = buf[i];
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occurences = 1;
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total_size += 3;
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}
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else occurences++;
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}
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return total_size;
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}
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uint32_t decompress_rle(void* data, uint32_t size, uint8_t *dest) {
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if (size < 1) return 0;
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uint32_t total_size = 0;
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uint8_t *buf = (uint8_t*)data;
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for (uint32_t i = 0; i < size; i += 3){
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uint16_t len = *(uint16_t*)&buf[i];
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for (uint16_t j = 0; j < len; j += 1){
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*dest++ = buf[i+2];
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total_size++;
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}
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}
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return total_size;
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}
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