Make the quantizer exact.

This replaces the approximate division-by-multiplication in the
 quantizer with an exact one that costs just one add and one
 shift extra.
The asm versions have not been updated in this patch, and thus
 have been disabled, since the new method requires different
 multipliers which are not compatible with the old method.

Change-Id: I53ac887af0f969d906e464c88b1f4be69c6b1206

diff --git a/vp8/encoder/arm/csystemdependent.c b/vp8/encoder/arm/csystemdependent.c
index 4521bfc3159b75d8ff26cca60145edd16c762675..bfceab16c0f17ce3389553ad10276f84c0d7d10b 100644 (file)
--- a/vp8/encoder/arm/csystemdependent.c
+++ b/vp8/encoder/arm/csystemdependent.c
@@ -63,7 +63,7 @@ void vp8_cmachine_specific_config(VP8_COMP *cpi)
     cpi->rtcd.encodemb.submbuv               = vp8_subtract_mbuv_neon;
 
     cpi->rtcd.quantize.quantb                = vp8_regular_quantize_b;
-    cpi->rtcd.quantize.fastquantb            = vp8_fast_quantize_b_neon;
+    /*cpi->rtcd.quantize.fastquantb            = vp8_fast_quantize_b_neon;*/
 #elif HAVE_ARMV6
     cpi->rtcd.variance.sad16x16              = vp8_sad16x16_c;
     cpi->rtcd.variance.sad16x8               = vp8_sad16x8_c;

diff --git a/vp8/encoder/block.h b/vp8/encoder/block.h
index b55bc51cb177dcb44e97277c75e7176e1fc362ca..19d307d26f090fb141b3feb8ca4ceaa205a298ca 100644 (file)
--- a/vp8/encoder/block.h
+++ b/vp8/encoder/block.h
@@ -33,6 +33,7 @@ typedef struct
 
     // 16 Y blocks, 4 U blocks, 4 V blocks each with 16 entries
     short(*quant)[4];
+    short(*quant_shift)[4];
     short(*zbin)[4];
     short(*zrun_zbin_boost);
     short(*round)[4];

diff --git a/vp8/encoder/encodeframe.c b/vp8/encoder/encodeframe.c
index 32cef1db1e1212726747a629f13b6897a73ef78e..a05b33268dec5d64149ef9aeb9748832e3b54a8d 100644 (file)
--- a/vp8/encoder/encodeframe.c
+++ b/vp8/encoder/encodeframe.c
@@ -103,6 +103,18 @@ static const int qzbin_factors[129] =
     80,
 };
 
+static void vp8cx_invert_quant(short *quant, short *shift, short d)
+{
+    unsigned t;
+    int l;
+    t = d;
+    for(l = 0; t > 1; l++)
+        t>>=1;
+    t = 1 + (1<<(16+l))/d;
+    *quant = (short)(t - (1<<16));
+    *shift = l;
+}
+
 void vp8cx_init_quantizer(VP8_COMP *cpi)
 {
     int r, c;
@@ -116,21 +128,24 @@ void vp8cx_init_quantizer(VP8_COMP *cpi)
     {
         // dc values
         quant_val = vp8_dc_quant(Q, cpi->common.y1dc_delta_q);
-        cpi->Y1quant[Q][0][0] = (1 << 16) / quant_val;
+        vp8cx_invert_quant(cpi->Y1quant[Q][0] + 0,
+                           cpi->Y1quant_shift[Q][0] + 0, quant_val);
         cpi->Y1zbin[Q][0][0] = ((qzbin_factors[Q] * quant_val) + 64) >> 7;
         cpi->Y1round[Q][0][0] = (qrounding_factors[Q] * quant_val) >> 7;
         cpi->common.Y1dequant[Q][0][0] = quant_val;
         cpi->zrun_zbin_boost_y1[Q][0] = (quant_val * zbin_boost[0]) >> 7;
 
         quant_val = vp8_dc2quant(Q, cpi->common.y2dc_delta_q);
-        cpi->Y2quant[Q][0][0] = (1 << 16) / quant_val;
+        vp8cx_invert_quant(cpi->Y2quant[Q][0] + 0,
+                           cpi->Y2quant_shift[Q][0] + 0, quant_val);
         cpi->Y2zbin[Q][0][0] = ((qzbin_factors[Q] * quant_val) + 64) >> 7;
         cpi->Y2round[Q][0][0] = (qrounding_factors[Q] * quant_val) >> 7;
         cpi->common.Y2dequant[Q][0][0] = quant_val;
         cpi->zrun_zbin_boost_y2[Q][0] = (quant_val * zbin_boost[0]) >> 7;
 
         quant_val = vp8_dc_uv_quant(Q, cpi->common.uvdc_delta_q);
-        cpi->UVquant[Q][0][0] = (1 << 16) / quant_val;
+        vp8cx_invert_quant(cpi->UVquant[Q][0] + 0,
+                           cpi->UVquant_shift[Q][0] + 0, quant_val);
         cpi->UVzbin[Q][0][0] = ((qzbin_factors[Q] * quant_val) + 64) >> 7;;
         cpi->UVround[Q][0][0] = (qrounding_factors[Q] * quant_val) >> 7;
         cpi->common.UVdequant[Q][0][0] = quant_val;
@@ -144,21 +159,24 @@ void vp8cx_init_quantizer(VP8_COMP *cpi)
             c = (rc & 3);
 
             quant_val = vp8_ac_yquant(Q);
-            cpi->Y1quant[Q][r][c] = (1 << 16) / quant_val;
+            vp8cx_invert_quant(cpi->Y1quant[Q][r] + c,
+                               cpi->Y1quant_shift[Q][r] + c, quant_val);
             cpi->Y1zbin[Q][r][c] = ((qzbin_factors[Q] * quant_val) + 64) >> 7;
             cpi->Y1round[Q][r][c] = (qrounding_factors[Q] * quant_val) >> 7;
             cpi->common.Y1dequant[Q][r][c] = quant_val;
             cpi->zrun_zbin_boost_y1[Q][i] = (quant_val * zbin_boost[i]) >> 7;
 
             quant_val = vp8_ac2quant(Q, cpi->common.y2ac_delta_q);
-            cpi->Y2quant[Q][r][c] = (1 << 16) / quant_val;
+            vp8cx_invert_quant(cpi->Y2quant[Q][r] + c,
+                               cpi->Y2quant_shift[Q][r] + c, quant_val);
             cpi->Y2zbin[Q][r][c] = ((qzbin_factors[Q] * quant_val) + 64) >> 7;
             cpi->Y2round[Q][r][c] = (qrounding_factors[Q] * quant_val) >> 7;
             cpi->common.Y2dequant[Q][r][c] = quant_val;
             cpi->zrun_zbin_boost_y2[Q][i] = (quant_val * zbin_boost[i]) >> 7;
 
             quant_val = vp8_ac_uv_quant(Q, cpi->common.uvac_delta_q);
-            cpi->UVquant[Q][r][c] = (1 << 16) / quant_val;
+            vp8cx_invert_quant(cpi->UVquant[Q][r] + c,
+                               cpi->UVquant_shift[Q][r] + c, quant_val);
             cpi->UVzbin[Q][r][c] = ((qzbin_factors[Q] * quant_val) + 64) >> 7;
             cpi->UVround[Q][r][c] = (qrounding_factors[Q] * quant_val) >> 7;
             cpi->common.UVdequant[Q][r][c] = quant_val;
@@ -198,6 +216,7 @@ void vp8cx_mb_init_quantizer(VP8_COMP *cpi, MACROBLOCK *x)
     for (i = 0; i < 16; i++)
     {
         x->block[i].quant = cpi->Y1quant[QIndex];
+        x->block[i].quant_shift = cpi->Y1quant_shift[QIndex];
         x->block[i].zbin = cpi->Y1zbin[QIndex];
         x->block[i].round = cpi->Y1round[QIndex];
         x->e_mbd.block[i].dequant = cpi->common.Y1dequant[QIndex];
@@ -211,6 +230,7 @@ void vp8cx_mb_init_quantizer(VP8_COMP *cpi, MACROBLOCK *x)
     for (i = 16; i < 24; i++)
     {
         x->block[i].quant = cpi->UVquant[QIndex];
+        x->block[i].quant_shift = cpi->UVquant_shift[QIndex];
         x->block[i].zbin = cpi->UVzbin[QIndex];
         x->block[i].round = cpi->UVround[QIndex];
         x->e_mbd.block[i].dequant = cpi->common.UVdequant[QIndex];
@@ -221,6 +241,7 @@ void vp8cx_mb_init_quantizer(VP8_COMP *cpi, MACROBLOCK *x)
     // Y2
     zbin_extra = (cpi->common.Y2dequant[QIndex][0][1] * ((cpi->zbin_over_quant / 2) + cpi->zbin_mode_boost)) >> 7;
     x->block[24].quant = cpi->Y2quant[QIndex];
+    x->block[24].quant_shift = cpi->Y2quant_shift[QIndex];
     x->block[24].zbin = cpi->Y2zbin[QIndex];
     x->block[24].round = cpi->Y2round[QIndex];
     x->e_mbd.block[24].dequant = cpi->common.Y2dequant[QIndex];

diff --git a/vp8/encoder/ethreading.c b/vp8/encoder/ethreading.c
index dd98a09d19a048448a66a0249264bad79aa577e8..54646f421bbb79ec7c4cc0dd76c891f69ae87160 100644 (file)
--- a/vp8/encoder/ethreading.c
+++ b/vp8/encoder/ethreading.c
@@ -286,6 +286,7 @@ static void setup_mbby_copy(MACROBLOCK *mbdst, MACROBLOCK *mbsrc)
     for (i = 0; i < 25; i++)
     {
         z->block[i].quant           = x->block[i].quant;
+        z->block[i].quant_shift     = x->block[i].quant_shift;
         z->block[i].zbin            = x->block[i].zbin;
         z->block[i].zrun_zbin_boost   = x->block[i].zrun_zbin_boost;
         z->block[i].round           = x->block[i].round;

diff --git a/vp8/encoder/onyx_int.h b/vp8/encoder/onyx_int.h
index fcde2205db6ee170a1a771b8c4e4b62908c08be8..f76d2efcdf463938165f590f032520441de61138 100644 (file)
--- a/vp8/encoder/onyx_int.h
+++ b/vp8/encoder/onyx_int.h
@@ -234,14 +234,17 @@ typedef struct
 {
 
     DECLARE_ALIGNED(16, short, Y1quant[QINDEX_RANGE][4][4]);
+    DECLARE_ALIGNED(16, short, Y1quant_shift[QINDEX_RANGE][4][4]);
     DECLARE_ALIGNED(16, short, Y1zbin[QINDEX_RANGE][4][4]);
     DECLARE_ALIGNED(16, short, Y1round[QINDEX_RANGE][4][4]);
 
     DECLARE_ALIGNED(16, short, Y2quant[QINDEX_RANGE][4][4]);
+    DECLARE_ALIGNED(16, short, Y2quant_shift[QINDEX_RANGE][4][4]);
     DECLARE_ALIGNED(16, short, Y2zbin[QINDEX_RANGE][4][4]);
     DECLARE_ALIGNED(16, short, Y2round[QINDEX_RANGE][4][4]);
 
     DECLARE_ALIGNED(16, short, UVquant[QINDEX_RANGE][4][4]);
+    DECLARE_ALIGNED(16, short, UVquant_shift[QINDEX_RANGE][4][4]);
     DECLARE_ALIGNED(16, short, UVzbin[QINDEX_RANGE][4][4]);
     DECLARE_ALIGNED(16, short, UVround[QINDEX_RANGE][4][4]);
 

diff --git a/vp8/encoder/quantize.c b/vp8/encoder/quantize.c
index 181870c1130a8119e85133c48f0c89a662537ebb..877002b08cf5c60778fe1ee24621e79f0b035734 100644 (file)
--- a/vp8/encoder/quantize.c
+++ b/vp8/encoder/quantize.c
@@ -25,6 +25,7 @@ void vp8_fast_quantize_b_c(BLOCK *b, BLOCKD *d)
     short *zbin_ptr   = &b->zbin[0][0];
     short *round_ptr  = &b->round[0][0];
     short *quant_ptr  = &b->quant[0][0];
+    short *quant_shift_ptr = &b->quant_shift[0][0];
     short *qcoeff_ptr = d->qcoeff;
     short *dqcoeff_ptr = d->dqcoeff;
     short *dequant_ptr = &d->dequant[0][0];
@@ -45,7 +46,9 @@ void vp8_fast_quantize_b_c(BLOCK *b, BLOCKD *d)
 
         if (x >= zbin)
         {
-            y  = ((x + round_ptr[rc]) * quant_ptr[rc]) >> 16; // quantize (x)
+            x += round_ptr[rc];
+            y  = (((x * quant_ptr[rc]) >> 16) + x)
+                 >> quant_shift_ptr[rc];                // quantize (x)
             x  = (y ^ sz) - sz;                         // get the sign back
             qcoeff_ptr[rc] = x;                          // write to destination
             dqcoeff_ptr[rc] = x * dequant_ptr[rc];        // dequantized value
@@ -69,6 +72,7 @@ void vp8_regular_quantize_b(BLOCK *b, BLOCKD *d)
     short *zbin_ptr   = &b->zbin[0][0];
     short *round_ptr  = &b->round[0][0];
     short *quant_ptr  = &b->quant[0][0];
+    short *quant_shift_ptr = &b->quant_shift[0][0];
     short *qcoeff_ptr = d->qcoeff;
     short *dqcoeff_ptr = d->dqcoeff;
     short *dequant_ptr = &d->dequant[0][0];
@@ -95,7 +99,9 @@ void vp8_regular_quantize_b(BLOCK *b, BLOCKD *d)
 
         if (x >= zbin)
         {
-            y  = ((x + round_ptr[rc]) * quant_ptr[rc]) >> 16; // quantize (x)
+            x += round_ptr[rc];
+            y  = (((x * quant_ptr[rc]) >> 16) + x)
+                 >> quant_shift_ptr[rc];                // quantize (x)
             x  = (y ^ sz) - sz;                         // get the sign back
             qcoeff_ptr[rc]  = x;                         // write to destination
             dqcoeff_ptr[rc] = x * dequant_ptr[rc];        // dequantized value

diff --git a/vp8/encoder/x86/x86_csystemdependent.c b/vp8/encoder/x86/x86_csystemdependent.c
index 11ef4197b4987174bfeed9383c56b1c2263e6af3..be226e040fccd11c1669fd84a9020775e7339738 100644 (file)
--- a/vp8/encoder/x86/x86_csystemdependent.c
+++ b/vp8/encoder/x86/x86_csystemdependent.c
@@ -238,7 +238,7 @@ void vp8_arch_x86_encoder_init(VP8_COMP *cpi)
         cpi->rtcd.encodemb.submby                = vp8_subtract_mby_mmx;
         cpi->rtcd.encodemb.submbuv               = vp8_subtract_mbuv_mmx;
 
-        cpi->rtcd.quantize.fastquantb            = vp8_fast_quantize_b_mmx;
+        /*cpi->rtcd.quantize.fastquantb            = vp8_fast_quantize_b_mmx;*/
     }
 
 #endif
@@ -285,8 +285,8 @@ void vp8_arch_x86_encoder_init(VP8_COMP *cpi)
         cpi->rtcd.encodemb.mbuverr               = vp8_mbuverror_xmm;
         /* cpi->rtcd.encodemb.sub* not implemented for wmt */
 
-        cpi->rtcd.quantize.fastquantb            = vp8_fast_quantize_b_sse;
-        cpi->rtcd.quantize.quantb            = vp8_regular_quantize_b_sse2;
+        /*cpi->rtcd.quantize.fastquantb            = vp8_fast_quantize_b_sse;
+        cpi->rtcd.quantize.quantb            = vp8_regular_quantize_b_sse2;*/
     }
 
 #endif