I tried the "--sout=...", specifically from my example, ::sprintf_s(smem_options, "#transcode{vcodec=RV24,acodec=none}:smem{video-postrender-callback=%lld,video-prerender-callback=%lld,video-data=%lld}", (long long int)(intptr_t)(void*)&handleStream, (long long int)(intptr_t)...