ref: b22cc559b6f3d17a5b230f239066158328bbfb9a
parent: 3536ad5bb9a630e58bd6503423023b16b40b201e
author: Yaowu Xu <yaowu@google.com>
date: Wed May 9 05:31:14 EDT 2012
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
--- a/configure
+++ b/configure
@@ -228,6 +228,7 @@
newupdate
superblocks
expanded_coef_context
+ int_8x8fdct
"
CONFIG_LIST="
external_build
--- a/vp8/encoder/dct.c
+++ b/vp8/encoder/dct.c
@@ -12,7 +12,250 @@
#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)
{int j1, i, j, k;
@@ -102,8 +345,8 @@
return;
}
+#endif
-
void vp8_short_fhaar2x2_c(short *input, short *output, int pitch) //pitch = 8
{/* [1 1 ; 1 -1] orthogonal transform */
@@ -214,4 +457,4 @@
ip += 4;
op += 4;
}
-}
+}
\ No newline at end of file
--- a/vp8/encoder/encodemb.c
+++ b/vp8/encoder/encodemb.c
@@ -239,7 +239,9 @@
{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_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_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_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],
--
⑨