Changed to use integer 8x8 dct

The commit added an integer version of 8x8 forward DCT, based on the
orginal forward DCT from VP6. The constants, roundings, and shifts
were adjusted to improve the accuracy. The latest patch has a very
similar accuracy in term of round trip error against the floating
point version.

It should be noted here that the purpose of the patch is to help
encoding speed and facilitate all other experiments. There will be
futher review in combination with inverse DCT before finalization.

configure with "--enable--int_8x8fdct" to use the integer version

Change-Id: I5a4f80507429f0e07cf02a13768ec81cbfddc5bc

diff --git a/configure b/configure
index 67171744bc4e504fc30c766e39ff416153a7a9ab..52ff9c898471218bf403228c99d940d6c6307fd9 100755 (executable)
--- a/configure
+++ b/configure
@@ -228,6 +228,7 @@ EXPERIMENT_LIST="
     newupdate
     superblocks
     expanded_coef_context
+    int_8x8fdct
 "
 CONFIG_LIST="
     external_build

diff --git a/vp8/encoder/dct.c b/vp8/encoder/dct.c
index e7505619a7d0cc2953d5f007095e0dd290aaa8bd..6f9c68ef756175c85254bb09217e92254744fd3a 100644 (file)
--- a/vp8/encoder/dct.c
+++ b/vp8/encoder/dct.c
@@ -12,6 +12,249 @@
 #include <math.h>
 #include "vpx_ports/config.h"
 
+#if CONFIG_INT_8X8FDCT
+
+static const int xC1S7 = 16069;
+static const int xC2S6 = 15137;
+static const int xC3S5 = 13623;
+static const int xC4S4 = 11585;
+static const int xC5S3 =  9102;
+static const int xC6S2 =  6270;
+static const int xC7S1 =  3196;
+
+#define SHIFT_BITS 14
+#define DOROUND(X) X += (1<<(SHIFT_BITS-1));
+
+#define FINAL_SHIFT 3
+#define FINAL_ROUNDING (1<<(FINAL_SHIFT -1))
+#define IN_SHIFT (FINAL_SHIFT+1)
+
+
+void vp8_short_fdct8x8_c ( short * InputData, short * OutputData, int pitch)
+{
+    int loop;
+    int short_pitch = pitch>>1;
+    int is07, is12, is34, is56;
+    int is0734, is1256;
+    int id07, id12, id34, id56;
+    int irot_input_x, irot_input_y;
+    int icommon_product1;      // Re-used product  (c4s4 * (s12 - s56))
+    int icommon_product2;      // Re-used product  (c4s4 * (d12 + d56))
+    int temp1, temp2;          // intermediate variable for computation
+
+    int  InterData[64];
+    int  *ip = InterData;
+    short *op = OutputData;
+
+    for (loop = 0; loop < 8; loop++)
+    {
+        // Pre calculate some common sums and differences.
+        is07 = (InputData[0] + InputData[7])<<IN_SHIFT;
+        is12 = (InputData[1] + InputData[2])<<IN_SHIFT;
+        is34 = (InputData[3] + InputData[4])<<IN_SHIFT;
+        is56 = (InputData[5] + InputData[6])<<IN_SHIFT;
+        id07 = (InputData[0] - InputData[7])<<IN_SHIFT;
+        id12 = (InputData[1] - InputData[2])<<IN_SHIFT;
+        id34 = (InputData[3] - InputData[4])<<IN_SHIFT;
+        id56 = (InputData[5] - InputData[6])<<IN_SHIFT;
+
+        is0734 = is07 + is34;
+        is1256 = is12 + is56;
+
+        // Pre-Calculate some common product terms.
+        icommon_product1 = xC4S4*(is12 - is56);
+        DOROUND(icommon_product1)
+        icommon_product1>>=SHIFT_BITS;
+
+        icommon_product2 = xC4S4*(id12 + id56);
+        DOROUND(icommon_product2)
+        icommon_product2>>=SHIFT_BITS;
+
+
+        ip[0] = (xC4S4*(is0734 + is1256));
+        DOROUND(ip[0]);
+        ip[0] >>= SHIFT_BITS;
+
+        ip[4] = (xC4S4*(is0734 - is1256));
+        DOROUND(ip[4]);
+        ip[4] >>= SHIFT_BITS;
+
+        // Define inputs to rotation for outputs 2 and 6
+        irot_input_x = id12 - id56;
+        irot_input_y = is07 - is34;
+
+        // Apply rotation for outputs 2 and 6.
+        temp1=xC6S2*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC2S6*irot_input_y;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        ip[2] = temp1 + temp2;
+
+        temp1=xC6S2*irot_input_y;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC2S6*irot_input_x ;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        ip[6] = temp1 -temp2 ;
+
+        // Define inputs to rotation for outputs 1 and 7
+        irot_input_x = icommon_product1 + id07;
+        irot_input_y = -( id34 + icommon_product2 );
+
+        // Apply rotation for outputs 1 and 7.
+        temp1=xC1S7*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC7S1*irot_input_y;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        ip[1] = temp1 - temp2;
+
+        temp1=xC7S1*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC1S7*irot_input_y ;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        ip[7] = temp1 + temp2 ;
+
+        // Define inputs to rotation for outputs 3 and 5
+        irot_input_x = id07 - icommon_product1;
+        irot_input_y = id34 - icommon_product2;
+
+        // Apply rotation for outputs 3 and 5.
+        temp1=xC3S5*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC5S3*irot_input_y ;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        ip[3] = temp1 - temp2 ;
+
+
+        temp1=xC5S3*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC3S5*irot_input_y;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        ip[5] = temp1 + temp2;
+
+        // Increment data pointer for next row
+        InputData += short_pitch ;
+        ip += 8;
+    }
+
+    // Performed DCT on rows, now transform the columns
+    ip = InterData;
+    for (loop = 0; loop < 8; loop++)
+    {
+        // Pre calculate some common sums and differences.
+        is07 = ip[0 * 8] + ip[7 * 8];
+        is12 = ip[1 * 8] + ip[2 * 8];
+        is34 = ip[3 * 8] + ip[4 * 8];
+        is56 = ip[5 * 8] + ip[6 * 8];
+
+        id07 = ip[0 * 8] - ip[7 * 8];
+        id12 = ip[1 * 8] - ip[2 * 8];
+        id34 = ip[3 * 8] - ip[4 * 8];
+        id56 = ip[5 * 8] - ip[6 * 8];
+
+        is0734 = is07 + is34;
+        is1256 = is12 + is56;
+
+        // Pre-Calculate some common product terms
+        icommon_product1 = xC4S4*(is12 - is56) ;
+        icommon_product2 = xC4S4*(id12 + id56) ;
+        DOROUND(icommon_product1)
+        DOROUND(icommon_product2)
+        icommon_product1>>=SHIFT_BITS;
+        icommon_product2>>=SHIFT_BITS;
+
+
+        temp1 = xC4S4*(is0734 + is1256) ;
+        temp2 = xC4S4*(is0734 - is1256) ;
+        DOROUND(temp1);
+        DOROUND(temp2);
+        temp1>>=SHIFT_BITS;
+
+        temp2>>=SHIFT_BITS;
+        op[0*8] = (temp1 + FINAL_ROUNDING)>>FINAL_SHIFT;
+        op[4*8] = (temp2 + FINAL_ROUNDING)>>FINAL_SHIFT;
+
+        // Define inputs to rotation for outputs 2 and 6
+        irot_input_x = id12 - id56;
+        irot_input_y = is07 - is34;
+
+        // Apply rotation for outputs 2 and 6.
+        temp1=xC6S2*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC2S6*irot_input_y;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        op[2*8] = (temp1 + temp2 + FINAL_ROUNDING)>>FINAL_SHIFT;
+
+        temp1=xC6S2*irot_input_y;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC2S6*irot_input_x ;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        op[6*8] = (temp1 -temp2 + FINAL_ROUNDING)>>FINAL_SHIFT ;
+
+        // Define inputs to rotation for outputs 1 and 7
+        irot_input_x = icommon_product1 + id07;
+        irot_input_y = -( id34 + icommon_product2 );
+
+        // Apply rotation for outputs 1 and 7.
+        temp1=xC1S7*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC7S1*irot_input_y;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        op[1*8] = (temp1 - temp2 + FINAL_ROUNDING)>>FINAL_SHIFT;
+
+        temp1=xC7S1*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC1S7*irot_input_y ;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        op[7*8] = (temp1 + temp2 + FINAL_ROUNDING)>>FINAL_SHIFT;
+
+        // Define inputs to rotation for outputs 3 and 5
+        irot_input_x = id07 - icommon_product1;
+        irot_input_y = id34 - icommon_product2;
+
+        // Apply rotation for outputs 3 and 5.
+        temp1=xC3S5*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC5S3*irot_input_y ;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        op[3*8] =  (temp1 - temp2 + FINAL_ROUNDING)>>FINAL_SHIFT ;
+
+
+        temp1=xC5S3*irot_input_x;
+        DOROUND(temp1);
+        temp1>>=SHIFT_BITS;
+        temp2=xC3S5*irot_input_y;
+        DOROUND(temp2);
+        temp2>>=SHIFT_BITS;
+        op[5*8] =  (temp1 + temp2 + FINAL_ROUNDING)>>FINAL_SHIFT;
+
+        // Increment data pointer for next column.
+        ip ++;
+        op ++;
+    }
+}
+#else
 
 void vp8_short_fdct8x8_c(short *block, short *coefs, int pitch)
 {
@@ -102,7 +345,7 @@ void vp8_short_fdct8x8_c(short *block, short *coefs, int pitch)
   return;
 }
 
-
+#endif
 
 void vp8_short_fhaar2x2_c(short *input, short *output, int pitch) //pitch = 8
 {
@@ -214,4 +457,4 @@ void vp8_short_walsh4x4_c(short *input, short *output, int pitch)
         ip += 4;
         op += 4;
     }
-}
+}
\ No newline at end of file

diff --git a/vp8/encoder/encodemb.c b/vp8/encoder/encodemb.c
index ae8ab8846fb9d6baa06d199dbcdf4d8770ae792d..81c69d9f85383eac8c585d1f0f74e11297687678 100644 (file)
--- a/vp8/encoder/encodemb.c
+++ b/vp8/encoder/encodemb.c
@@ -239,7 +239,9 @@ void vp8_transform_mbuv_8x8(MACROBLOCK *x)
 {
     int i;
 
+#if !CONFIG_INT_8X8FDCT
     vp8_clear_system_state();
+#endif
 
     for (i = 16; i < 24; i += 4)
     {
@@ -252,9 +254,9 @@ void vp8_transform_mbuv_8x8(MACROBLOCK *x)
 void vp8_transform_intra_mby_8x8(MACROBLOCK *x)//changed
 {
     int i;
-
+#if !CONFIG_INT_8X8FDCT
     vp8_clear_system_state();
-
+#endif
     for (i = 0; i < 9; i += 8)
     {
         x->vp8_short_fdct8x8(&x->block[i].src_diff[0],
@@ -279,9 +281,9 @@ void vp8_transform_intra_mby_8x8(MACROBLOCK *x)//changed
 void vp8_transform_mb_8x8(MACROBLOCK *x)
 {
     int i;
-
+#if !CONFIG_INT_8X8FDCT
     vp8_clear_system_state();
-
+#endif
     for (i = 0; i < 9; i += 8)
     {
         x->vp8_short_fdct8x8(&x->block[i].src_diff[0],
@@ -312,9 +314,9 @@ void vp8_transform_mb_8x8(MACROBLOCK *x)
 void vp8_transform_mby_8x8(MACROBLOCK *x)
 {
     int i;
-
+#if !CONFIG_INT_8X8FDCT
     vp8_clear_system_state();
-
+#endif
     for (i = 0; i < 9; i += 8)
     {
         x->vp8_short_fdct8x8(&x->block[i].src_diff[0],