From d1bf93392898f1393b9063e5d88eccb656c0dc40 Mon Sep 17 00:00:00 2001
From: Joao Carreira <jfmcarreira@gmail.com>
Date: Fri, 27 Feb 2015 13:57:40 +0000
Subject: [PATCH] Optimize pixel conversion from yuv to rgb

---
 lib/PlaYUVerFrame.cpp             |  2 +-
 lib/PlaYUVerFramePixelFormats.cpp | 44 +++++++++++++++++++------------
 lib/PlaYUVerFramePixelFormats.h   | 32 ++++++----------------
 3 files changed, 36 insertions(+), 42 deletions(-)

diff --git a/lib/PlaYUVerFrame.cpp b/lib/PlaYUVerFrame.cpp
index cbd6e34..6a229a0 100644
--- a/lib/PlaYUVerFrame.cpp
+++ b/lib/PlaYUVerFrame.cpp
@@ -249,7 +249,7 @@ PlaYUVerFrame::Pixel PlaYUVerFrame::ConvertPixel( PlaYUVerFrame::Pixel inputPixe
 
   if( eOutputSpace == COLOR_RGB )
   {
-    yuvToRgb( inputPixel.Y(), inputPixel.Cb(), inputPixel.Cr(), outA, outB, outC );
+    YUV2RGB( inputPixel.Y(), inputPixel.Cb(), inputPixel.Cr(), outA, outB, outC );
     outPixel.R() = outA;
     outPixel.G() = outB;
     outPixel.B() = outC;
diff --git a/lib/PlaYUVerFramePixelFormats.cpp b/lib/PlaYUVerFramePixelFormats.cpp
index ddce223..df05e68 100644
--- a/lib/PlaYUVerFramePixelFormats.cpp
+++ b/lib/PlaYUVerFramePixelFormats.cpp
@@ -67,23 +67,34 @@ Void bufferFromFrameYUVProgressive( Pel*** in, Pel *out, UInt width, UInt height
 
 Void fillRGBbufferYUV( Pel*** in, UChar* out, UInt width, UInt height, UInt ratioChromaHor, UInt ratioChromaVer )
 {
-  Pel** pY = in[LUMA];
-  Pel** pU = in[CHROMA_U];
-  Pel** pV = in[CHROMA_V];
+  Pel* pY = in[LUMA][0];
+  Pel* pU = in[CHROMA_U][0];
+  Pel* pV = in[CHROMA_V][0];
   Int iY, iU, iV, iR, iG, iB;
   UInt* buff = ( UInt* )out;
 
-  for( UInt y = 0; y < height; y++ )
+  pU -= width >> ratioChromaHor;
+  pV -= width >> ratioChromaHor;
+  for( UInt y = 0; y < height >> ratioChromaVer; y++ )
   {
-    for( UInt x = 0; x < width; x++ )
+    pU += width >> ratioChromaHor;
+    pV += width >> ratioChromaHor;
+    for( Int i = 0; i < 1 << ratioChromaVer; i++ )
     {
-      // Pixel (x, y).
-      iY = pY[y][x];
-      iU = pU[y >> ratioChromaVer][x >> ratioChromaHor] - 128;
-      iV = pV[y >> ratioChromaVer][x >> ratioChromaHor] - 128;
-      yuvToRgb<Int>( iY, iU, iV, iR, iG, iB );
-      *buff = pelRgb( iR, iG, iB );
-      buff++;
+      for( UInt x = 0; x < width >> ratioChromaHor; x++ )
+      {
+        iU = *pU++ - 128;
+        iV = *pV++ - 128;
+        for( Int j = 0; j < 1 << ratioChromaHor; j++ )
+        {
+          iY = *pY++;
+          YUV2RGB( iY, iU, iV, iR, iG, iB );
+          *buff = PEL_RGB( iR, iG, iB );
+          buff++;
+        }
+      }
+      pU -= width >> ratioChromaHor;
+      pV -= width >> ratioChromaHor;
     }
   }
 }
@@ -234,7 +245,7 @@ Void fillRGBbufferGray( Pel*** in, UChar* out, UInt width, UInt height )
   for( UInt i = 0; i < height * width; i++ )
   {
     iY = *inPel;
-    *buff++ = pelRgb( iY, iY, iY );
+    *buff++ = PEL_RGB( iY, iY, iY );
     inPel++;
   }
 }
@@ -259,9 +270,9 @@ Void frameFromBufferRGB( Pel *in, Pel*** out, UInt64 size, Pel* pFirst, Pel* pSe
 {
   for( UInt i = 0; i < size; i++ )
   {
-    *pFirst++  = *in++;
+    *pFirst++ = *in++;
     *pSecond++ = *in++;
-    *pthird++  = *in++;
+    *pthird++ = *in++;
   }
 }
 Void bufferFromFrameRGB( Pel ***in, Pel* out, UInt64 size, Pel* pFirst, Pel* pSecond, Pel* pthird )
@@ -285,7 +296,7 @@ Void fillRGBbufferRGB( Pel*** in, UChar* out, UInt width, UInt height )
     iR = *pR++;
     iG = *pG++;
     iB = *pB++;
-    *buff++ = pelRgb( iR, iG, iB );
+    *buff++ = PEL_RGB( iR, iG, iB );
   }
 }
 
@@ -343,5 +354,4 @@ PlaYUVerFramePelFormat g_PlaYUVerFramePelFormatsList[PLAYUVER_NUMBER_FORMATS] =
   RGB24,
   BGR24, };
 
-
 }  // NAMESPACE
diff --git a/lib/PlaYUVerFramePixelFormats.h b/lib/PlaYUVerFramePixelFormats.h
index 9b57c5f..b3439ea 100644
--- a/lib/PlaYUVerFramePixelFormats.h
+++ b/lib/PlaYUVerFramePixelFormats.h
@@ -22,7 +22,6 @@
  * \brief    Handling the pixel formats definition
  */
 
-
 #ifndef __PLAYUVERFRAMEPIXELFORMATS_H__
 #define __PLAYUVERFRAMEPIXELFORMATS_H__
 
@@ -32,26 +31,13 @@
 namespace plaYUVer
 {
 
-static inline Void yuvToRgb( Int iY, Int iU, Int iV, Int &iR, Int &iG, Int &iB )
-{
-  iR = iY + 1402 * iV / 1000;
-  iG = iY - ( 101004 * iU + 209599 * iV ) / 293500;
-  iB = iY + 1772 * iU / 1000;
+#define CLAMP(X) X = X < 0 ? 0 : X > 255 ? 255 : X;
 
-  if( iR < 0 )
-    iR = 0;
-  if( iG < 0 )
-    iG = 0;
-  if( iB < 0 )
-    iB = 0;
-
-  if( iR > 255 )
-    iR = 255;
-  if( iG > 255 )
-    iG = 255;
-  if( iB > 255 )
-    iB = 255;
-}
+#define YUV2RGB(  iY, iU, iV, iR, iG, iB ) \
+    iR = iY + ( ( 1436 * iV ) >> 10 ); \
+    iG = iY - ( ( 352 * iU + 731 * iV ) >> 10 ); \
+    iB = iY + ( ( 1812 * iU ) >> 10 ); \
+    CLAMP(iR) CLAMP(iG) CLAMP(iB)
 
 static inline Void rgbToYuv( Int iR, Int iG, Int iB, Int &iY, Int &iU, Int &iV )
 {
@@ -80,10 +66,8 @@ inline Int pelAlpha( UInt rgb )           // get alpha part of RGBA
   return rgb >> 24;
 }
 
-inline UInt pelRgb( Int r, Int g, Int b )  // set RGB value
-{
-  return ( 0xffu << 24 ) | ( ( r & 0xff ) << 16 ) | ( ( g & 0xff ) << 8 ) | ( b & 0xff );
-}
+#define PEL_RGB( r, g, b ) \
+    ( 0xffu << 24 ) | ( ( r & 0xff ) << 16 ) | ( ( g & 0xff ) << 8 ) | ( b & 0xff )
 
 struct structPlaYUVerFramePelFormat
 {