[SCM] libav/experimental: H.264: eliminate non-transposed scantable support. It was an ugly hack to begin with and didn't give any performance.

siretart at users.alioth.debian.org siretart at users.alioth.debian.org
Sun Jun 30 17:21:50 UTC 2013


The following commit has been merged in the experimental branch:
commit ca32f7f2083f9ededd1d9964ed065e0ad07a01e0
Author: Jason Garrett-Glaser <darkshikari at gmail.com>
Date:   Fri Jan 14 19:04:59 2011 +0000

    H.264: eliminate non-transposed scantable support.
    It was an ugly hack to begin with and didn't give any performance.
    
    NOTE: this patch opens up some future simplifications to be made (such as
    removing some of the scantables from H264Context) but doesn't take advantage
    of them yet.
    
    Originally committed as revision 26329 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index 7c47cfb..b11d947 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -687,7 +687,6 @@ static void free_tables(H264Context *h){
 
 static void init_dequant8_coeff_table(H264Context *h){
     int i,q,x;
-    const int transpose = (h->h264dsp.h264_idct8_add != ff_h264_idct8_add_c); //FIXME ugly
     h->dequant8_coeff[0] = h->dequant8_buffer[0];
     h->dequant8_coeff[1] = h->dequant8_buffer[1];
 
@@ -701,7 +700,7 @@ static void init_dequant8_coeff_table(H264Context *h){
             int shift = div6[q];
             int idx = rem6[q];
             for(x=0; x<64; x++)
-                h->dequant8_coeff[i][q][transpose ? (x>>3)|((x&7)<<3) : x] =
+                h->dequant8_coeff[i][q][(x>>3)|((x&7)<<3)] =
                     ((uint32_t)dequant8_coeff_init[idx][ dequant8_coeff_init_scan[((x>>1)&12) | (x&3)] ] *
                     h->pps.scaling_matrix8[i][x]) << shift;
         }
@@ -710,7 +709,6 @@ static void init_dequant8_coeff_table(H264Context *h){
 
 static void init_dequant4_coeff_table(H264Context *h){
     int i,j,q,x;
-    const int transpose = (h->h264dsp.h264_idct_add != ff_h264_idct_add_c); //FIXME ugly
     for(i=0; i<6; i++ ){
         h->dequant4_coeff[i] = h->dequant4_buffer[i];
         for(j=0; j<i; j++){
@@ -726,7 +724,7 @@ static void init_dequant4_coeff_table(H264Context *h){
             int shift = div6[q] + 2;
             int idx = rem6[q];
             for(x=0; x<16; x++)
-                h->dequant4_coeff[i][q][transpose ? (x>>2)|((x<<2)&0xF) : x] =
+                h->dequant4_coeff[i][q][(x>>2)|((x<<2)&0xF)] =
                     ((uint32_t)dequant4_coeff_init[idx][(x&1) + ((x>>2)&1)] *
                     h->pps.scaling_matrix4[i][x]) << shift;
         }
@@ -1597,31 +1595,19 @@ static int init_poc(H264Context *h){
  */
 static void init_scan_tables(H264Context *h){
     int i;
-    if(h->h264dsp.h264_idct_add == ff_h264_idct_add_c){ //FIXME little ugly
-        memcpy(h->zigzag_scan, zigzag_scan, 16*sizeof(uint8_t));
-        memcpy(h-> field_scan,  field_scan, 16*sizeof(uint8_t));
-    }else{
-        for(i=0; i<16; i++){
+    for(i=0; i<16; i++){
 #define T(x) (x>>2) | ((x<<2) & 0xF)
-            h->zigzag_scan[i] = T(zigzag_scan[i]);
-            h-> field_scan[i] = T( field_scan[i]);
+        h->zigzag_scan[i] = T(zigzag_scan[i]);
+        h-> field_scan[i] = T( field_scan[i]);
 #undef T
-        }
     }
-    if(h->h264dsp.h264_idct8_add == ff_h264_idct8_add_c){
-        memcpy(h->zigzag_scan8x8,       ff_zigzag_direct,     64*sizeof(uint8_t));
-        memcpy(h->zigzag_scan8x8_cavlc, zigzag_scan8x8_cavlc, 64*sizeof(uint8_t));
-        memcpy(h->field_scan8x8,        field_scan8x8,        64*sizeof(uint8_t));
-        memcpy(h->field_scan8x8_cavlc,  field_scan8x8_cavlc,  64*sizeof(uint8_t));
-    }else{
-        for(i=0; i<64; i++){
+    for(i=0; i<64; i++){
 #define T(x) (x>>3) | ((x&7)<<3)
-            h->zigzag_scan8x8[i]       = T(ff_zigzag_direct[i]);
-            h->zigzag_scan8x8_cavlc[i] = T(zigzag_scan8x8_cavlc[i]);
-            h->field_scan8x8[i]        = T(field_scan8x8[i]);
-            h->field_scan8x8_cavlc[i]  = T(field_scan8x8_cavlc[i]);
+        h->zigzag_scan8x8[i]       = T(ff_zigzag_direct[i]);
+        h->zigzag_scan8x8_cavlc[i] = T(zigzag_scan8x8_cavlc[i]);
+        h->field_scan8x8[i]        = T(field_scan8x8[i]);
+        h->field_scan8x8_cavlc[i]  = T(field_scan8x8_cavlc[i]);
 #undef T
-        }
     }
     if(h->sps.transform_bypass){ //FIXME same ugly
         h->zigzag_scan_q0          = zigzag_scan;
diff --git a/libavcodec/h264idct.c b/libavcodec/h264idct.c
index 31e072f..86c5ef2 100644
--- a/libavcodec/h264idct.c
+++ b/libavcodec/h264idct.c
@@ -34,23 +34,23 @@ static av_always_inline void idct_internal(uint8_t *dst, DCTELEM *block, int str
     block[0] += 1<<(shift-1);
 
     for(i=0; i<4; i++){
-        const int z0=  block[0 + block_stride*i]     +  block[2 + block_stride*i];
-        const int z1=  block[0 + block_stride*i]     -  block[2 + block_stride*i];
-        const int z2= (block[1 + block_stride*i]>>1) -  block[3 + block_stride*i];
-        const int z3=  block[1 + block_stride*i]     + (block[3 + block_stride*i]>>1);
-
-        block[0 + block_stride*i]= z0 + z3;
-        block[1 + block_stride*i]= z1 + z2;
-        block[2 + block_stride*i]= z1 - z2;
-        block[3 + block_stride*i]= z0 - z3;
-    }
-
-    for(i=0; i<4; i++){
         const int z0=  block[i + block_stride*0]     +  block[i + block_stride*2];
         const int z1=  block[i + block_stride*0]     -  block[i + block_stride*2];
         const int z2= (block[i + block_stride*1]>>1) -  block[i + block_stride*3];
         const int z3=  block[i + block_stride*1]     + (block[i + block_stride*3]>>1);
 
+        block[i + block_stride*0]= z0 + z3;
+        block[i + block_stride*1]= z1 + z2;
+        block[i + block_stride*2]= z1 - z2;
+        block[i + block_stride*3]= z0 - z3;
+    }
+
+    for(i=0; i<4; i++){
+        const int z0=  block[0 + block_stride*i]     +  block[2 + block_stride*i];
+        const int z1=  block[0 + block_stride*i]     -  block[2 + block_stride*i];
+        const int z2= (block[1 + block_stride*i]>>1) -  block[3 + block_stride*i];
+        const int z3=  block[1 + block_stride*i]     + (block[3 + block_stride*i]>>1);
+
         dst[i + 0*stride]= cm[ add*dst[i + 0*stride] + ((z0 + z3) >> shift) ];
         dst[i + 1*stride]= cm[ add*dst[i + 1*stride] + ((z1 + z2) >> shift) ];
         dst[i + 2*stride]= cm[ add*dst[i + 2*stride] + ((z1 - z2) >> shift) ];
@@ -78,51 +78,51 @@ void ff_h264_idct8_add_c(uint8_t *dst, DCTELEM *block, int stride){
 
     for( i = 0; i < 8; i++ )
     {
-        const int a0 =  block[0+i*8] + block[4+i*8];
-        const int a2 =  block[0+i*8] - block[4+i*8];
-        const int a4 = (block[2+i*8]>>1) - block[6+i*8];
-        const int a6 = (block[6+i*8]>>1) + block[2+i*8];
+        const int a0 =  block[i+0*8] + block[i+4*8];
+        const int a2 =  block[i+0*8] - block[i+4*8];
+        const int a4 = (block[i+2*8]>>1) - block[i+6*8];
+        const int a6 = (block[i+6*8]>>1) + block[i+2*8];
 
         const int b0 = a0 + a6;
         const int b2 = a2 + a4;
         const int b4 = a2 - a4;
         const int b6 = a0 - a6;
 
-        const int a1 = -block[3+i*8] + block[5+i*8] - block[7+i*8] - (block[7+i*8]>>1);
-        const int a3 =  block[1+i*8] + block[7+i*8] - block[3+i*8] - (block[3+i*8]>>1);
-        const int a5 = -block[1+i*8] + block[7+i*8] + block[5+i*8] + (block[5+i*8]>>1);
-        const int a7 =  block[3+i*8] + block[5+i*8] + block[1+i*8] + (block[1+i*8]>>1);
+        const int a1 = -block[i+3*8] + block[i+5*8] - block[i+7*8] - (block[i+7*8]>>1);
+        const int a3 =  block[i+1*8] + block[i+7*8] - block[i+3*8] - (block[i+3*8]>>1);
+        const int a5 = -block[i+1*8] + block[i+7*8] + block[i+5*8] + (block[i+5*8]>>1);
+        const int a7 =  block[i+3*8] + block[i+5*8] + block[i+1*8] + (block[i+1*8]>>1);
 
         const int b1 = (a7>>2) + a1;
         const int b3 =  a3 + (a5>>2);
         const int b5 = (a3>>2) - a5;
         const int b7 =  a7 - (a1>>2);
 
-        block[0+i*8] = b0 + b7;
-        block[7+i*8] = b0 - b7;
-        block[1+i*8] = b2 + b5;
-        block[6+i*8] = b2 - b5;
-        block[2+i*8] = b4 + b3;
-        block[5+i*8] = b4 - b3;
-        block[3+i*8] = b6 + b1;
-        block[4+i*8] = b6 - b1;
+        block[i+0*8] = b0 + b7;
+        block[i+7*8] = b0 - b7;
+        block[i+1*8] = b2 + b5;
+        block[i+6*8] = b2 - b5;
+        block[i+2*8] = b4 + b3;
+        block[i+5*8] = b4 - b3;
+        block[i+3*8] = b6 + b1;
+        block[i+4*8] = b6 - b1;
     }
     for( i = 0; i < 8; i++ )
     {
-        const int a0 =  block[i+0*8] + block[i+4*8];
-        const int a2 =  block[i+0*8] - block[i+4*8];
-        const int a4 = (block[i+2*8]>>1) - block[i+6*8];
-        const int a6 = (block[i+6*8]>>1) + block[i+2*8];
+        const int a0 =  block[0+i*8] + block[4+i*8];
+        const int a2 =  block[0+i*8] - block[4+i*8];
+        const int a4 = (block[2+i*8]>>1) - block[6+i*8];
+        const int a6 = (block[6+i*8]>>1) + block[2+i*8];
 
         const int b0 = a0 + a6;
         const int b2 = a2 + a4;
         const int b4 = a2 - a4;
         const int b6 = a0 - a6;
 
-        const int a1 = -block[i+3*8] + block[i+5*8] - block[i+7*8] - (block[i+7*8]>>1);
-        const int a3 =  block[i+1*8] + block[i+7*8] - block[i+3*8] - (block[i+3*8]>>1);
-        const int a5 = -block[i+1*8] + block[i+7*8] + block[i+5*8] + (block[i+5*8]>>1);
-        const int a7 =  block[i+3*8] + block[i+5*8] + block[i+1*8] + (block[i+1*8]>>1);
+        const int a1 = -block[3+i*8] + block[5+i*8] - block[7+i*8] - (block[7+i*8]>>1);
+        const int a3 =  block[1+i*8] + block[7+i*8] - block[3+i*8] - (block[3+i*8]>>1);
+        const int a5 = -block[1+i*8] + block[7+i*8] + block[5+i*8] + (block[5+i*8]>>1);
+        const int a7 =  block[3+i*8] + block[5+i*8] + block[1+i*8] + (block[1+i*8]>>1);
 
         const int b1 = (a7>>2) + a1;
         const int b3 =  a3 + (a5>>2);

-- 
Libav/FFmpeg packaging



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