#ifdef__clang__#defineSTBIDEF static inline#endif#defineSTB_IMAGE_STATIC#defineSTB_IMAGE_IMPLEMENTATION#include"stb_image.h"#defineSTB_IMAGE_WRITE_IMPLEMENTATION#include"stb_image_write.h"#include<stdio.h>#include<stdlib.h>#include<sys/stat.h>unsignedchar*read_binary_file(constchar*filename,size_t*size) {FILE*file=fopen(filename,"rb");if (file==NULL) {fprintf(stderr,"Error opening file: %s\n",filename);returnNULL;    }structstatst;if (stat(filename,&st)!=0) {fprintf(stderr,"Error getting file size\n");fclose(file);returnNULL;    }*size=st.st_size;unsignedchar*buffer= (unsignedchar*)malloc(*size);if (buffer==NULL) {fprintf(stderr,"Error allocating memory\n");fclose(file);returnNULL;    }size_tbytes_read=fread(buffer,1,*size,file);if (bytes_read!=*size) {fprintf(stderr,"Error reading file: expected %zu bytes, got %zu bytes\n",*size,bytes_read);free(buffer);fclose(file);returnNULL;    }fclose(file);returnbuffer;}intmain(intargc,constchar*argv[]) {if (argc!=3) {printf("Usage: %s <gif file> <output dir>\n",argv[0]);exit(1);    }size_tfile_size;unsignedchar*filedata=read_binary_file(argv[1],&file_size);intx,y,z,comp;int*delays=NULL;unsignedchar*data=stbi_load_gif_from_memory(filedata, (int)file_size,&delays,&x,&y,&z,&comp,0);if (data==NULL) {fprintf(stderr,"Error loading image\n");return1;    }unsignedchar*start=data;size_tframe_size=x*y*sizeof(unsignedchar)*4;char*filename= (char*)malloc(1024);for (inti=0;i<z;++i) {bzero(filename,1024);snprintf(filename,1023,"%s/%d.png",argv[2],i);stbi_write_png(filename,x,y,4,start,0);start+=frame_size;    }free(filename);STBI_FREE((void*)data);STBI_FREE((void*)delays);}

$cd stb$ gcc -I$(pwd) gif-background.c -o gif-background$ mkdir -p ./output$ gif-background ./horse.gif ./output