@Fria 27 November 2021 edited more from that month

Lossless Data Compression: Run Length Encoding/Decoding using C Language

Run length encoding is one of the simplest lossless data compression algorithm and it goes like this just count the number of same adjacent characters and write <number of characters> <character>... and so on. Example: Data to encode: ABBBBCCCDDDDEEEE Encoded data: 1A4B3C4D4E --- Encoder --- Flowchart: (Note: n=0 is 1 character to n=255 is 256 characters)

Source Code: /* RLE Encoder */ #include <stdio.h> int main(int argc,char **argv) { int ch1,ch2,n; FILE *fin,*fout; if(argc!=3) { printf("syntax: %s src dst\n",argv[0]); return -1; } if((fin=fopen(argv[1],"rb"))==NULL) { printf("error: opening file: %s\n",argv[1]); return -1; } if((fout=fopen(argv[2],"wb"))==NULL) { printf("error: opening file: %s\n",argv[2]); return -1; } ch1=fgetc(fin); while(ch1!=EOF) { n=0; while((ch2=fgetc(fin))!=EOF && ch1==ch2) { n++; if(n==255) { fputc(n,fout); fputc(ch1,fout); n=-1; } } if(n>=0) { fputc(n,fout); fputc(ch1,fout); } ch1=ch2; } fclose(fout); fclose(fin); return 0; } --- Decoder --- Flowchart:

Source Code: /* RLE Decoder */ #include <stdio.h> int main(int argc,char **argv) { int ch,n,i; FILE *fin,*fout; if(argc!=3) { printf("syntax: %s src dst\n",argv[0]); return -1; } if((fin=fopen(argv[1],"rb"))==NULL) { printf("error: opening file: %s\n",argv[1]); return -1; } if((fout=fopen(argv[2],"wb"))==NULL) { printf("error: opening file: %s\n",argv[2]); return -1; } while((n=fgetc(fin))!=EOF) { ch=fgetc(fin); if(ch==EOF) break; for(i=0;i<=n;i++) { fputc(ch,fout); } } fclose(fout); fclose(fin); return 0; } https://youtu.be/Nyj73PXj49Q Links: **source:** https://github.com/rald/rledos