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@@ -0,0 +1,67 @@
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+#include <stdio.h>
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+#include <fcntl.h>
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+#include <stdint.h>
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+
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+#define LEN_THRESH (3)
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+
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+FILE *in, *out;
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+uint8_t data, datalast;
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+uint16_t len, first=1;
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+size_t off;
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+
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+uint16_t getrunlength(uint8_t data) {
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+ uint16_t count=1;
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+ while(fgetc(in)==data && count<65535) {
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+ if(feof(in))break;
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+ count++;
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+ }
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+ return count;
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+}
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+
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+void writerle(uint8_t data, uint16_t len) {
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+ if(len<256) {
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+ fputc(0x5b, out);
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+ fputc(data, out);
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+ fputc(len & 0xff, out);
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+ } else {
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+ fputc(0x77, out);
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+ fputc(data, out);
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+ fputc(len & 0xff, out);
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+ fputc(len >> 8, out);
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+ }
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+}
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+
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+void writeliteral(uint8_t data) {
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+ if(data==0x5b || data==0x77 || data==0x9b) {
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+ fputc(0x9b, out);
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+ }
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+ fputc(data, out);
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+}
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+
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+int main(int argc, char** argv) {
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+ if((in=fopen(argv[1], "rb"))==NULL) {
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+ perror("could not open input file");
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+ return 1;
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+ }
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+ if((out=fopen(argv[2], "wb"))==NULL) {
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+ perror("could not open output file");
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+ fclose(in);
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+ return 1;
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+ }
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+ len=0;
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+ while(!feof(in)) {
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+ data=fgetc(in);
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+ if(feof(in))break;
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+ off=ftell(in);
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+ if((len=getrunlength(data)) > LEN_THRESH) {
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+ writerle(data, len);
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+ fseek(in, -1, SEEK_CUR);
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+ } else {
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+ fseek(in, off, SEEK_SET);
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+ writeliteral(data);
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+ }
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+ }
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+ fclose(out);
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+ fclose(in);
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+ return 0;
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+}
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