\unprotect

\installnamespace{MPanimationvariables}

\unexpanded\def\startMPanimation
    {\dodoublegroupempty\meta_start_animation}

\def\meta_start_animation#1%
    {\normalexpanded{\meta_start_animation_indeed{#1}}}

\unexpanded\def\meta_start_animation_indeed#1#2#3\stopMPanimation
    {\doifsomething{#2}{\getparameters[\????MPanimationvariables#1:][#2]}%
     \setgvalue{\??mpgraphic animation:#1}{\meta_handle_use_graphic{#1}{n,t}{#3}}}

\let\stopMPanimation\relax

\unexpanded\def\useMPanimation%
    {\dosingleargument\use_meta_animation}

\def\use_meta_animation[#1]#2%
    {\edef\c_MP_animation_frames{\getvalue{\????MPanimationvariables#2:n}}%
     \startanimation[#1]
        \dorecurse{\c_MP_animation_frames}
            {\expanded{\frame{\useMPgraphic{animation:#2}{n=\c_MP_animation_frames,t=\recurselevel}}}}
     \stopanimation}

\protect