\usetikzlibrary{arrows,matrix}
% \usepackage{amssymb, amsmath, mathptmx}

\begin{tikzpicture}[font=\scriptsize,node distance=1cm,scale=1.2]

\tikzstyle{sumBlock}=[draw,circle, inner sep=0cm, minimum size=0.1cm]
\tikzstyle{processBlock}=[draw, fill=\TikZColorFill, inner sep=0.1cm, minimum size=0.7cm,text centered]
\tikzstyle{proposedBlock}=[processBlock, fill=gray!30]
\tikzstyle{blockArrow}=[draw,-latex]
\tikzstyle{point} = [draw, fill=black, circle,inner sep=1pt]

\coordinate (sumPoint) at (0,0);
\node[sumBlock] (ResidueDiff) at (sumPoint) {$+$};


% \begin{scope}[xshift=-2cm, yshift=3.2cm, scale=1.5]
%   \def\spacing{.2}
%   \node at ((.5+3*\spacing*.5,-.5) (Input) {};
%   \foreach \i in {0,...,3}
%     \draw[thick,fill=white] (\spacing*\i,-.15*\i) rectangle ++(1,1);
% %   \node[text width=.7cm, text centered] at (1.6,1.1) {Video Stream};
% %   \node[text width=.7cm, text centered] at (1.1,.1) {Input video};
% \end{scope}


\node[left of=ResidueDiff,text width=1cm,node distance=2.5cm] (Input) {\textbf{Input video}};
\path[blockArrow] (Input) --  (ResidueDiff) node [point, midway] (p0) {};

\node[processBlock,right=of ResidueDiff] (Transf) {$T$};
\node[processBlock,right=of Transf] (Quant) {$Q$};
\node[processBlock,right=of Quant] (VLC) {CABAC};

\node[right=of VLC, text centered,text width=1.5cm] (Output) {\textbf{HEVC bitstream}};
\path[blockArrow] (VLC) --  (Output);


\path[blockArrow] (ResidueDiff) --  (Transf);
\path[blockArrow] (Transf) --  (Quant);
\path[blockArrow] (Quant) --  (VLC) node [point,midway] (QuantFrame) {};

\node[processBlock,below=.8 of QuantFrame] (InvQuant) {$Q^{-1}$};
\node[processBlock,right=0.7 of InvQuant] (InvTransf) {$T^{-1}$};
\node[sumBlock,below=.5 of InvTransf] (ReconResidue) {$+$};
\node[processBlock,text width=1.9cm, below=.8 of ReconResidue] (Filters) {Deblocking \& SAO filters};

\path[blockArrow] (QuantFrame) --  (InvQuant);
\path[blockArrow] (InvQuant) --  (InvTransf);
\path[blockArrow] (InvTransf) --  (ReconResidue);
\path[blockArrow] (ReconResidue) --  (Filters) node[point,midway] (p1) {};

\node[left=.4 of InvQuant, coordinate,yshift=0.5cm] (x1) {};
\path[blockArrow,-] (x1 -| ResidueDiff) node[point] () {} -- (x1);
\path[blockArrow] (x1)  |- (ReconResidue);

\node [processBlock,text width=1.5cm] (Intra) at (2.2,-1.8) {Intra prediction};
\node [processBlock,text width=1.5cm,below=1.2 of Intra] (Inter) {Inter prediction};

\path[blockArrow] (p1) -|  (Intra);

\node [point,left=.8 of Intra] (z1) {};
\node [point,left=.8 of Inter] (z2) {};

\path[blockArrow,-] (Intra) --  (z1);
\path[blockArrow,-] (Inter) --  (z2);

\node [coordinate,left of=z1,below of=z1,node distance=0.15cm] (w1) {};
\node [coordinate,left of=z2, above of=z2, node distance=0.15cm] (w2) {};

\path (z1) -- (z2) node [coordinate, midway] (w) {};
\path (w) -- (w -| sumPoint) node [point] (z) {};

\draw[-latex,densely dashed] (w1) to [bend left=60] (w2);
\draw [thick,blockArrow] (z1)+(0.1,-0.1) -- (z);

\path[blockArrow] (z) --  node[pos=0.96,right] {-} (ResidueDiff);

\node[processBlock,below=of Filters,text width=2cm] (RefBuffer) {Decoded Picture Buffer};

\node[processBlock,text width=1.5cm] at(Inter |- RefBuffer) (MotionSearch) {Motion Estimation};

\path[blockArrow] (Filters) --  (RefBuffer) node[point,pos=0.4] (p2) {};
\path[blockArrow] (RefBuffer) --  (MotionSearch);
\path[blockArrow] (MotionSearch) --  (Inter);
\path[blockArrow] (p0) |-  (MotionSearch);


\node[right of=p2, text centered,text width=1.5cm, node distance=2.3cm] (Output) {\textbf{Video output}};
\path[blockArrow] (p2) --  (Output);


\end{tikzpicture}