tex.sx-q-448512

% https://tex.stackexchange.com/questions/448512/total-number-of-frames-in-subsubsection

\documentclass{beamer}
\begin{document}

\makeatletter
\newif\ifincurrentsection
\newif\ifincurrentsubsection
\newif\ifincurrentsubsubsection
\newif\ifincurrentframe
\def\counteverything{
	{
		\def\stopcountingsubsubsection{
			\ifx\subsubcount\undefined\else
				\subsubindex-th frame out of \\
				\subsubcount\ frames in current subsubsection
				\global\let\subsubcount\undefined
			\fi
		}
		\def\headcommand##1{##1}
		\def\beamer@documentpages##1{
			\stopcountingsubsubsection
		}
		\def\sectionentry##1##2##3##4##5{
			\stopcountingsubsubsection
		}
		\def\beamer@subsectionentry##1##2##3##4##5{
			\stopcountingsubsubsection
		}
		\def\beamer@subsubsectionentry##1##2##3##4##5##6{
			\stopcountingsubsubsection
			\ifnum\c@section=##2
				\incurrentsectiontrue
			\else
				\incurrentsectionfalse
			\fi
			\ifnum\c@subsection=##3
				\incurrentsubsectiontrue
			\else
				\incurrentsubsectionfalse
			\fi
			\ifnum\c@subsubsection=##4
				\incurrentsubsubsectiontrue
			\else
				\incurrentsubsubsectionfalse
			\fi
			\ifincurrentsection
				\ifincurrentsubsection
					\ifincurrentsubsubsection
						\xdef\subsubcount{0}
					\fi
				\fi
			\fi
		}
		\def\slideentry##1##2##3##4##5##6{
			\ifnum\c@subsectionslide=##3
				\incurrentframetrue
			\else
				\incurrentframefalse
			\fi
		}
		\def\beamer@sectionpages##1##2{}
		\def\beamer@subsectionpages##1##2{}
		\def\beamer@framepages##1##2{
			\ifincurrentsection
				\ifincurrentsubsection
					\ifincurrentsubsubsection
						\pgfmathtruncatemacro\subsubcount{\subsubcount+1}
						\ifincurrentframe
							\xdef\subsubindex{\subsubcount}
						\fi
					\fi
				\fi
			\fi
		}
		\input{\jobname.nav}
	}
}
\setbeamertemplate{frametitle}{
	\counteverything
}

\section{Sec1}
	\subsection{Sec1-Ssec1}
		\subsubsection{Sec1-Ssec1-sssec1}
			\frame{{.}A}
			\frame{{.}B\pause C}
		\subsubsection{Sec1-Ssec1-sssec2}
			\frame{{.}A}
			\frame{{.}B\pause C}
			\frame{{.}D\pause E\pause F}
	\subsection{Sec1-Ssec2}
		\subsubsection{Sec1-Ssec2-sssec1}
			\frame{{.}A}
			\frame{{.}B\pause C}
			\frame{{.}D\pause E\pause F}
			\frame{{.}G\pause H\pause I\pause J}
		\subsubsection{Sec1-Ssec2-sssec2}
			\frame{{.}A}
			\frame{{.}B\pause C}
			\frame{{.}D\pause E\pause F}
			\frame{{.}G\pause H\pause I\pause J}
			\frame{{.}K\pause L\pause M\pause N\pause O}

\section{Sec2}
	\subsection{Sec2-Ssec1}
		\subsubsection{Sec2-Ssec1-sssec1}
			\frame{{.}A}
			\frame{{.}B\pause C}
		\subsubsection{Sec2-Ssec1-sssec2}
			\frame{{.}A}
			\frame{{.}B\pause C}
			\frame{{.}D\pause E\pause F}
	\subsection{Sec1-Ssec2}
		\subsubsection{Sec2-Ssec2-sssec1}
			\frame{{.}A}
			\frame{{.}B\pause C}
			\frame{{.}D\pause E\pause F}
			\frame{{.}G\pause H\pause I\pause J}
		\subsubsection{Sec2-Ssec2-sssec2}
			\frame{{.}A}
			\frame{{.}B\pause C}
			\frame{{.}D\pause E\pause F}
			\frame{{.}G\pause H\pause I\pause J}
			\frame{{.}K\pause L\pause M\pause N\pause O}

\end{document}