Brand new mdct, roughly 35-40% faster on all block sizes (reduced

computation, reduced memory usage).

Monty

svn path=/trunk/vorbis/; revision=1113

1 files changed, 35 insertions, 5 deletions

diff --git a/lib/mdct.h b/lib/mdct.h
index d6d584ab..1318df99 100644
--- a/lib/mdct.h
+++ b/lib/mdct.h
@@ -12,7 +12,7 @@
  ********************************************************************
 
  function: modified discrete cosine transform prototypes
- last mod: $Id: mdct.h,v 1.13 2000/11/06 00:07:01 xiphmont Exp $
+ last mod: $Id: mdct.h,v 1.14 2000/12/16 01:49:39 xiphmont Exp $
 
  ********************************************************************/
 
@@ -21,19 +21,49 @@
 
 #include "vorbis/codec.h"
 
+//#define MDCT_INTEGERIZED  <- be warned there could be some hurt left here
+#ifdef MDCT_INTEGERIZED
+
+#define DATA_TYPE int
+#define REG_TYPE  register int
+#define TRIGBITS 14
+#define cPI3_8 6270
+#define cPI2_8 11585
+#define cPI1_8 15137
+
+#define FLOAT_CONV(x) ((int)((x)*(1<<TRIGBITS)+.5))
+#define MULT_NORM(x) ((x)>>TRIGBITS)
+#define HALVE(x) ((x)>>1)
+
+#else
+
+#define DATA_TYPE float
+#define REG_TYPE  float
+#define cPI3_8 .38268343236508977175F
+#define cPI2_8 .70710678118654752441F
+#define cPI1_8 .92387953251128675613F
+
+#define FLOAT_CONV(x) (x)
+#define MULT_NORM(x) (x)
+#define HALVE(x) ((x)*.5)
+
+#endif
+
+
 typedef struct {
   int n;
   int log2n;
   
-  float *trig;
-  int    *bitrev;
+  DATA_TYPE *trig;
+  int       *bitrev;
 
+  DATA_TYPE scale;
 } mdct_lookup;
 
 extern void mdct_init(mdct_lookup *lookup,int n);
 extern void mdct_clear(mdct_lookup *l);
-extern void mdct_forward(mdct_lookup *init, float *in, float *out);
-extern void mdct_backward(mdct_lookup *init, float *in, float *out);
+extern void mdct_forward(mdct_lookup *init, DATA_TYPE *in, DATA_TYPE *out);
+extern void mdct_backward(mdct_lookup *init, DATA_TYPE *in, DATA_TYPE *out);
 
 #endif