ffmpeg -i rtsp://ip -i zone0.png -i zone1.png \
    -filter_complex "[0:v]fps=fps=3,scale=ih/2:iw/2,split=2[in1][in2]; \
    [in1][1:v]overlay,metadata=add:key=id:value=0,select='gte(scene\,0)',metadata=print[out1]; \
    [in2][2:v]overlay,metadata=add:key=id:value=1,select='gte(scene\,0)',metadata=print[out2]" \
    -map "[out1]" -f null - \
    -map "[out2]" -f null -