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

\begin{tikzpicture}[font=\footnotesize,node distance=1.5cm]

\tikzstyle{sumBlock}=[draw,circle, inner sep=0cm, minimum size=0.1cm]


\tikzstyle{templateBlock}   = [inner sep=0.1cm, text centered]
\tikzstyle{processBlock}    = [templateBlock, draw, fill=TikZColorFill, minimum height=0.9cm, text width=2cm]
\tikzstyle{proposedBlock}   = [processBlock, fill=gray!30]
\tikzstyle{labels}          = [templateBlock, text width=2cm, font=\scriptsize]
\tikzstyle{blockArrow}      = [draw,-latex]
\tikzstyle{arrowControl}    = [blockArrow, dashed]
\tikzstyle{arrowOutput}     = [blockArrow, shorten >=6, thick]
\tikzstyle{point}           = [draw, fill=black, circle,inner sep=1pt]

\tikzstyle{frame} = [anchor=north west, inner sep=0]
\tikzstyle{ctu}   = [draw, step=12.8mm]

\def\framescale{0.23753}

%% CUs
% \begin{scope}[scale=\framescale, every node/.style={scale=\framescale}]
\node[frame, on grid] at (0,0) (FrameCU) {\includegraphics[width=2cm]{FrameList/RaceCUCrop} };
% \draw[ctu] (0,0) grid ++(84.2mm,-48.0mm);
% \end{scope}
\node[labels, above=0 of FrameCU] {Coding Units quad-tree};

%% CTUs
\node[frame, on grid] at (0,-2.5cm) (FrameCTU) {\includegraphics[width=2cm]{FrameList/RaceCTUCrop} };

\begin{scope}[yshift=-5cm]
\def\spacing{.1}
\node[frame] at (\spacing*-2 ,\spacing*0 )  (is) {\includegraphics[width=2cm]{FrameList/Race_CodedCrop} };
\node[frame] at (\spacing*-1 ,\spacing*-1)       {\includegraphics[width=2cm]{FrameList/Race_CodedCrop} };
\node[frame] at (\spacing*0  ,\spacing*-2)       {\includegraphics[width=2cm]{FrameList/Race_CodedCrop} };
\node[frame] at (\spacing*1  ,\spacing*-3)       {\includegraphics[width=2cm]{FrameList/Race_CodedCrop} };
\node[frame] at (\spacing*2  ,\spacing*-4)  (ie) {\includegraphics[width=2cm]{FrameList/Race_CodedCrop} };
\node[fit=(is) (ie), inner sep=1pt] (in) {};
\end{scope}


\path[blockArrow] (in) --  (FrameCTU) node[labels, text width=1.5cm, midway, left] {Partitioning into CTUs};
\path[blockArrow] (FrameCTU) --  (FrameCU);

\node[sumBlock, right=1.2 of FrameCU] (ResidueDiff) {$+$};

%% CTUs
\node[frame, right=2.2cm of FrameCU] (FTu) {\includegraphics[width=2cm]{FrameList/RaceTUCrop} };

\node[labels, text width=2.3cm, above=0 of FTu] {Transform Units \\quad-tree};

\node[processBlock, text width=.9cm, right=0.5 of FTu] (Transf) {$T$};
\node[processBlock, text width=.9cm, right=0.5 of Transf] (Quant) {$Q$};
\node[processBlock, text width=3.3cm, above=1 of Transf, xshift=.5cm] (GCC) {Encoder control};

\node[labels,right=1.8 of Quant] (QuantCoef) {Quantized Coefficients};
\node[labels,right=2.7 of GCC] (ControlData) {Control data};

\path[blockArrow] (Quant) --  (QuantCoef) node [point,pos=0.5] (pointQuant) {};

\node[processBlock, below=0.5 of pointQuant, text width=.9cm,] (InvQuant) {$Q^{-1}$};
\node[processBlock, below=0.5 of InvQuant, text width=.9cm, ] (InvTransf) {$T^{-1}$};

\node[sumBlock,                      below=0.6 of InvTransf] (ReconResidue) {$+$};

\node[processBlock, below=.9 of FTu, xshift=.9cm] (IntraEstm) {Intra-frame estimation};
\node[labels, scale=.8, below=0 of IntraEstm.200, align=right, yshift=-3] {34 modes};

\node[processBlock, below=.6 of IntraEstm] (Intra) {Intra prediction};
\node[processBlock, below=.9 of Intra] (Inter) {Inter prediction};
\node[processBlock, below=.6 of Inter] (MotionSearch) {Motion Estimation};
% \node[labels, scale=.8, below=0 of MotionSearch, text width=2cm] {Symmetric \& asymmetric partitions};
\node[labels, scale=.8, below=0 of MotionSearch.200, align=right, yshift=-3, text width=4cm] {AMVP, Merge Mode};

\node[processBlock, below=1.2 of ReconResidue, text width=2.3cm] (Filters) {Deblocking \& SAO filters};
% \node[processBlock, text width=2.3cm] at (Filters |- MotionSearch) (RefBuffer) {Decoded Picture Buffer};
\node[processBlock, text width=2.3cm] at (Filters |- MotionSearch) (RPSet) {Reference Picture Set};


%% Intra / Inter prediction arrows
\node [point,left=.7 of Intra] (IntraPred) {};
\node [point,left=.7 of Inter] (InterPred) {};
\path[blockArrow,-] (Intra) --  (IntraPred);
\path[blockArrow,-] (Inter) --  (InterPred);
\node[coordinate,left of=IntraPred, below of=IntraPred, node distance=0.15cm] (w1) {};
\node[coordinate,left of=InterPred, above of=InterPred, node distance=0.15cm] (w2) {};
\path (IntraPred) -- (InterPred) node [coordinate, midway] (pointPred) {};
\path (pointPred) -- (pointPred -| ResidueDiff) node [point] (pointPred) {};
\draw[-latex,densely dashed] (w1) to [bend left=60] (w2);
\draw[thick,blockArrow] (IntraPred)+(0.1,-0.1) -- (pointPred);
\path[blockArrow] (pointPred) --  node[pos=0.96,right] {-} (ResidueDiff);


\path[blockArrow] (FrameCU) --  (ResidueDiff) node [point, midway] (pointIn) {};
\path[blockArrow] (ReconResidue) --  (Filters) node[point,pos=.4] (pointRecon) {};

% \path[blockArrow] (ResidueDiff) --  (Transf);
\path[blockArrow] (ResidueDiff) --  (FTu);
\path[blockArrow] (FTu) --  (Transf);

\path[blockArrow] (pointIn) |- (GCC);
\path[blockArrow] (GCC) --  (ControlData);

\path[blockArrow] (pointQuant) --  (InvQuant);
\path[blockArrow] (InvQuant) --  (InvTransf);
\path[blockArrow] (InvTransf) --  (ReconResidue);

\path[blockArrow] (pointRecon) -|  (Intra);
% \path[blockArrow] (RefBuffer) --  (RPSet);
% \path[blockArrow] (RPSet) --  (MotionSearch);
\path[blockArrow] (Filters) --  (RPSet);
\path[blockArrow] (RPSet) --  (MotionSearch);

\path[blockArrow] (IntraEstm) -- (Intra);
\path[blockArrow] (MotionSearch) -- (Inter);
\path[blockArrow] (pointIn) |-  (MotionSearch);

\path[blockArrow] (pointIn |- IntraEstm) node[point] {} --  (IntraEstm);

\node[left=.6 of InvQuant, coordinate] (x1) {};
\path[blockArrow,-] (x1 -| ResidueDiff) node[point] () {} -- (x1);
\path[blockArrow] (x1)  |- (ReconResidue);


\node[processBlock,right=2.5 of ReconResidue] (VLC) {Header Formatting \& CABAC};
\begin{pgfonlayer}{background}

\path[arrowControl] (GCC -| Quant.90)         --  (Quant.90);
\path[arrowControl] (GCC -| IntraEstm.30)     --  (IntraEstm.30);
\path[arrowControl] (GCC -| MotionSearch.60) --  (MotionSearch.60);

\path[arrowOutput] (QuantCoef)        --  (VLC.135);
\path[arrowOutput] (ControlData.-30)  --  (VLC);
\path[arrowOutput] (MotionSearch)     --  (VLC.190)     node[labels,above, pos=0.7, yshift=.2cm] {Motion \\ vectors};
\path[arrowOutput] (IntraEstm)        --  (VLC)         node[labels,above, pos=0.8, yshift=.2cm] {Intra \\ modes};
\path[arrowOutput] (Filters)          --  (VLC.220)     node[labels,below, pos=0.7, yshift=-.2cm] {Filter \\ data};

\end{pgfonlayer}



\node[right=1 of VLC, text centered,text width=1.7cm] (Output) {\textbf{HEVC NALUs}};
\path[blockArrow] (VLC) --  (Output);



\end{tikzpicture}