[xiph-cvs] cvs commit: w3d Makefile golomb.h

[Holger Waechtler]

holger      01/11/20 03:33:08

  Modified:    .        Makefile golomb.h
  Log:
  introduced a fast adaption path for large numbers in the golomb coder

Revision  Changes    Path
1.21      +2 -2      w3d/Makefile

Index: Makefile
===================================================================
RCS file: /usr/local/cvsroot/w3d/Makefile,v
retrieving revision 1.20
retrieving revision 1.21
diff -u -r1.20 -r1.21
--- Makefile	2001/11/20 11:15:00	1.20
+++ Makefile	2001/11/20 11:33:05	1.21
@@ -1,7 +1,7 @@
 CC = gcc
 RM = rm -rf
 
-CFLAGS = -pg -O2 -Wall -I../ogg/ogg/include
+CFLAGS = -g -O0 -Wall -I../ogg/ogg/include
 
 # use 16 bit signed integers as wavelet coefficients
 CFLAGS+= -DTYPE=int16_t
@@ -24,7 +24,7 @@
 # disable assertions
 #CFLAGS+= -DNDEBUG
 
-LFLAGS = -pg -lefence -logg -L../ogg/ogg/src/.libs
+LFLAGS = -g -lefence -logg -L../ogg/ogg/src/.libs
 
 OBJS = mem.o pnm.o wavelet.o wavelet_xform.o wavelet_coeff.o \
         yuv.o tarkin.o info.o

1.2       +15 -45    w3d/golomb.h

Index: golomb.h
===================================================================
RCS file: /usr/local/cvsroot/w3d/golomb.h,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- golomb.h	2001/11/20 11:15:00	1.1
+++ golomb.h	2001/11/20 11:33:05	1.2
@@ -6,28 +6,6 @@
 
 
 static inline
-void write_number_unary (BitCoderState *b, unsigned int x)
-{
-   while (x--)
-      bitcoder_write_bit (b, 1);
-
-   bitcoder_write_bit (b, 0);
-}
-
-
-static inline
-unsigned int read_number_unary (BitCoderState *b)
-{
-   unsigned int x = 0;
-
-   while (bitcoder_read_bit (b))
-      x++;
-
-   return x;
-}
-
-
-static inline
 void write_number_binary (BitCoderState *b, unsigned int x, int bits)
 {
    while (bits) {
@@ -69,39 +47,31 @@
    unsigned int q, r;
 
    assert (x > 0);
+
+
+   while ((q = (x - 1) >> bits) > 0) {
+      bitcoder_write_bit (b, 1);   /* fast temporary adaption, write  */ 
+      bits++;                      /* unary representation of q       */
+   };
 
-   q = (x - 1) >> bits;
+   bitcoder_write_bit (b, 0);
+
    r = x - 1 - (q << bits); 
 
-   if (q >= 15) {
-      if (x > 0xffff) {
-         write_number_unary (b, 16);
-         write_number_binary (b, x, 32);
-      } else {
-         write_number_unary (b, 15);
-         write_number_binary (b, x, 16);
-      }
-   } else {
-      write_number_unary (b, q);
-      write_number_binary (b, r, bits);
-   }
+   write_number_binary (b, r, bits);
 }
 
 
 static inline
 unsigned int golomb_read_number (BitCoderState *b, int bits)
 {
-   unsigned int q, r, x;
+   unsigned int q = 0, r, x;
 
-   q = read_number_unary (b);
-   if (q == 15)
-      x = read_number_binary (b, 16);
-   else if (q == 16)
-      x = read_number_binary (b, 32);
-   else {
-      r = read_number_binary (b, bits);
-      x = (q << bits) + r + 1;
-   }
+   while (bitcoder_read_bit (b) != 0)
+      bits++;
+
+   r = read_number_binary (b, bits);
+   x = (q << bits) + r + 1;
 
    return x;
 }

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