From d9b7cc22680dcfb3ea90a8c0281bf5634da56a34 Mon Sep 17 00:00:00 2001
From: kramm <kramm>
Date: Sat, 2 Aug 2003 12:26:26 +0000
Subject: [PATCH] moved out- the functions in here used to be in swfvideo.c.

---
 lib/h.263/dct.c |  177 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/h.263/dct.h |   13 ++++
 2 files changed, 190 insertions(+)
 create mode 100644 lib/h.263/dct.c
 create mode 100644 lib/h.263/dct.h

diff --git a/lib/h.263/dct.c b/lib/h.263/dct.c
new file mode 100644
index 0000000..309d4cd
--- /dev/null
+++ b/lib/h.263/dct.c
@@ -0,0 +1,177 @@
+int zigzagtable[64] = {
+    0, 1, 5, 6, 14, 15, 27, 28,
+    2, 4, 7, 13, 16, 26, 29, 42,
+    3, 8, 12, 17, 25, 30, 41, 43,
+    9, 11, 18, 24, 31, 40, 44, 53,
+    10, 19, 23, 32, 39, 45, 52, 54,
+    20, 22, 33, 38, 46, 51, 55, 60,
+    21, 34, 37, 47, 50, 56, 59, 61,
+    35, 36, 48, 49, 57, 58, 62, 63};
+
+static double table[8][8] =
+{
+{0.707106781186548,0.707106781186548,0.707106781186548,0.707106781186548,0.707106781186548,0.707106781186548,0.707106781186548,0.707106781186548},
+{0.980785280403230,0.831469612302545,0.555570233019602,0.195090322016128,-0.195090322016128,-0.555570233019602,-0.831469612302545,-0.980785280403230},
+{0.923879532511287,0.382683432365090,-0.382683432365090,-0.923879532511287,-0.923879532511287,-0.382683432365090,0.382683432365090,0.923879532511287},
+{0.831469612302545,-0.195090322016128,-0.980785280403230,-0.555570233019602,0.555570233019602,0.980785280403230,0.195090322016129,-0.831469612302545},
+{0.707106781186548,-0.707106781186547,-0.707106781186548,0.707106781186547,0.707106781186548,-0.707106781186547,-0.707106781186547,0.707106781186547},
+{0.555570233019602,-0.980785280403230,0.195090322016128,0.831469612302545,-0.831469612302545,-0.195090322016128,0.980785280403231,-0.555570233019602},
+{0.382683432365090,-0.923879532511287,0.923879532511287,-0.382683432365090,-0.382683432365091,0.923879532511287,-0.923879532511286,0.382683432365090},
+{0.195090322016128,-0.555570233019602,0.831469612302545,-0.980785280403231,0.980785280403230,-0.831469612302545,0.555570233019602,-0.195090322016129}
+};
+
+void dct(int*src)
+{
+    double tmp[64];
+    int x,y,u,v,t;
+
+    for(v=0;v<8;v++)
+    for(u=0;u<8;u++)
+    {
+	double c = 0;
+	for(x=0;x<8;x++)
+	{
+	    c+=table[u][x]*src[v*8+x];
+	}
+	tmp[v*8+u] = c;
+    }
+    for(u=0;u<8;u++)
+    for(v=0;v<8;v++)
+    {
+	double c = 0;
+	for(y=0;y<8;y++)
+	{
+	    c+=table[v][y]*tmp[y*8+u];
+	}
+	src[v*8+u] = (int)(c*0.25+0.5);
+    }
+}
+
+void idct(int*src)
+{
+    double tmp[64];
+    int x,y,u,v;
+    for(y=0;y<8;y++)
+    for(x=0;x<8;x++)
+    {
+	double c = 0;
+	for(u=0;u<8;u++)
+	{
+	    c+=table[u][x]*src[y*8+u];
+	}
+	tmp[y*8+x] = c;
+    }
+    for(y=0;y<8;y++)
+    for(x=0;x<8;x++)
+    {
+	double c = 0;
+	for(v=0;v<8;v++)
+	{
+	    c+=table[v][y]*tmp[v*8+x];
+	}
+	src[y*8+x] = (int)(c*0.25+0.5);
+    }
+}
+
+static double c[8] = {1.0,
+0.980785280403230, // cos(Pi*1/16), sin(Pi*7/16)
+0.923879532511287, // cos(Pi*2/16), sin(Pi*6/16)
+0.831469612302545, // cos(Pi*3/16), sin(Pi*5/16)
+0.707106781186548, // cos(Pi*4/16), sin(Pi*4/16), 1/sqrt(2)
+0.555570233019602, // cos(Pi*5/16), sin(Pi*3/16)
+0.382683432365090, // cos(Pi*6/16), sin(Pi*2/16)
+0.195090322016128 // cos(Pi*7/16), sin(Pi*1/16)
+};
+
+static double cc[8];
+static int ccquant = -1;
+
+void preparequant(int quant)
+{
+    if(ccquant == quant)
+	return;
+    cc[0] = c[0]/(quant*2*4);
+    cc[1] = c[1]/(quant*2*4);
+    cc[2] = c[2]/(quant*2*4);
+    cc[3] = c[3]/(quant*2*4);
+    cc[4] = c[4]/(quant*2*4);
+    cc[5] = c[5]/(quant*2*4);
+    cc[6] = c[6]/(quant*2*4);
+    cc[7] = c[7]/(quant*2*4);
+    ccquant = quant;
+}
+
+inline static void innerdct(const double*a,double*b, const double*c)
+{
+    // c1*c7*2 = c6
+    // c2*c6*2 = c4
+    // c3*c5*2 = c2
+    // c4*c4*2 = 1
+
+     //{  1,  3,  5,  7, -7, -5, -3, -1},
+     //{  3, -7, -1, -5,  5,  1,  7, -3},
+     //{  5, -1,  7,  3, -3, -7,  1, -5},
+     //{  7, -5,  3, -1,  1, -3,  5, -7}
+    double b0,b1,b2,b3,b4,b5;
+    b2 = (a[0]+a[7]);
+    b3 = (a[1]+a[6]);
+    b4 = (a[2]+a[5]);
+    b5 = (a[3]+a[4]);
+
+    b0 = (b2+b5)*c[4];
+    b1 = (b3+b4)*c[4];
+    b[0*8] = b0 + b1;
+    b[4*8] = b0 - b1;
+    b[2*8] = (b2-b5)*c[2] + (b3-b4)*c[6];
+    b[6*8] = (b2-b5)*c[6] + (b4-b3)*c[2];
+
+    b0 = (a[0]-a[7]);
+    b1 = (a[1]-a[6]);
+    b2 = (a[2]-a[5]);
+    b3 = (a[3]-a[4]);
+
+    b[1*8] = b0*c[1] + b1*c[3] + b2*c[5] + b3*c[7];
+    b[3*8] = b0*c[3] - b1*c[7] - b2*c[1] - b3*c[5];
+    b[5*8] = b0*c[5] - b1*c[1] + b2*c[7] + b3*c[3];
+    b[7*8] = b0*c[7] - b1*c[5] + b2*c[3] - b3*c[1];
+}
+
+void dct2(int*src, int*dest)
+{
+    double tmp[64], tmp2[64];
+    double*p;
+    int u,x,v,t;
+
+    for(t=0;t<64;t++)
+	tmp2[t] = src[t];
+
+    for(v=0;v<8;v++)
+    {
+	double* a=&tmp2[v*8];
+	double* b=&tmp[v];
+	innerdct(a,b,c);
+    }
+    for(v=0;v<8;v++)
+    {
+	double* a=&tmp[v*8];
+	double* b=&tmp2[v];
+	innerdct(a,b,cc);
+    }
+    for(t=0;t<64;t++) {
+	int v = (int)(tmp2[t]);
+	dest[zigzagtable[t]] = v;
+    }
+}
+
+
+void zigzag(int*src)
+{
+    int tmp[64];
+    int t;
+    for(t=0;t<64;t++) {
+	tmp[zigzagtable[t]] = src[t];
+    }
+    memcpy(src, tmp, sizeof(int)*64);
+}
+
+
diff --git a/lib/h.263/dct.h b/lib/h.263/dct.h
new file mode 100644
index 0000000..6d7e411
--- /dev/null
+++ b/lib/h.263/dct.h
@@ -0,0 +1,13 @@
+#ifndef __dct_h__
+#define __dct_h__
+    
+void dct(int*src);
+void idct(int*src);
+
+void preparequant(int quant);
+void dct2(int*src, int*dest);
+
+int zigzagtable[64];
+void zigzag(int*src);
+
+#endif //__dct_h__
-- 
1.7.10.4