QOI image decoding and encoding for SDL2 in C99. Copy SDL_QOI.h, SDL_QOI.c and qoi.h into your project.
SDL_Surface* sur = SDL_LoadQOI("./SDL_logo.qoi");
SDL_Texture* tex = SDL_LoadQOI_Texture(renderer, "./SDL_logo.qoi");
SDL_SaveQOI(sur, "SDL_logo2.qoi");See example.c for a working example with SDL logo (mkdir build && cd build && cmake .. && make && ./example).