ref: 31e91fdd154690af55d8a043ec96a86ecc414172
parent: a2a56b3ea59188e2e2b60b69a0a8f77aa3093144
author: menno <menno>
date: Tue Oct 1 17:55:49 EDT 2002
Fixed random number generator
--- a/libfaad/common.c
+++ b/libfaad/common.c
@@ -16,7 +16,7 @@
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
-** $Id: common.c,v 1.3 2002/09/27 08:37:22 menno Exp $
+** $Id: common.c,v 1.4 2002/10/01 21:55:49 menno Exp $
**/
/* just some common functions that could be used anywhere */
@@ -88,6 +88,59 @@
}
return -1;
+}
+
+static const uint8_t Parity [256] = { // parity+ 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+ 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
+ 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
+ 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+ 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
+ 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+ 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
+ 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0
+};
+
+static uint32_t __r1 = 1;
+static uint32_t __r2 = 1;
+
+
+/*
+ * This is a simple random number generator with good quality for audio purposes.
+ * It consists of two polycounters with opposite rotation direction and different
+ * periods. The periods are coprime, so the total period is the product of both.
+ *
+ * -------------------------------------------------------------------------------------------------
+ * +-> |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0|
+ * | -------------------------------------------------------------------------------------------------
+ * | | | | | | |
+ * | +--+--+--+-XOR-+--------+
+ * | |
+ * +--------------------------------------------------------------------------------------+
+ *
+ * -------------------------------------------------------------------------------------------------
+ * |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0| <-+
+ * ------------------------------------------------------------------------------------------------- |
+ * | | | | |
+ * +--+----XOR----+--+ |
+ * | |
+ * +----------------------------------------------------------------------------------------+
+ *
+ *
+ * The first has an period of 3*5*17*257*65537, the second of 7*47*73*178481,
+ * which gives a period of 18.410.713.077.675.721.215. The result is the
+ * XORed values of both generators.
+ */
+uint32_t random_int(void)
+{+ uint32_t t1, t2, t3, t4;
+
+ t3 = t1 = __r1; t4 = t2 = __r2; // Parity calculation is done via table lookup, this is also available
+ t1 &= 0xF5; t2 >>= 25; // on CPUs without parity, can be implemented in C and avoid unpredictable
+ t1 = Parity [t1]; t2 &= 0x63; // jumps and slow rotate through the carry flag operations.
+ t1 <<= 31; t2 = Parity [t2];
+
+ return (__r1 = (t3 >> 1) | t1 ) ^ (__r2 = (t4 + t4) | t2 );
}
#if 0
--- a/libfaad/common.h
+++ b/libfaad/common.h
@@ -16,7 +16,7 @@
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
-** $Id: common.h,v 1.23 2002/09/27 08:37:22 menno Exp $
+** $Id: common.h,v 1.24 2002/10/01 21:55:49 menno Exp $
**/
#ifndef __COMMON_H__
@@ -205,6 +205,7 @@
uint32_t int_log2(uint32_t val);
int8_t can_decode_ot(uint8_t object_type);
uint8_t get_sr_index(uint32_t samplerate);
+uint32_t random_int(void);
#ifndef M_PI
#define M_PI 3.14159265358979323846f
--- a/libfaad/dither.c
+++ b/libfaad/dither.c
@@ -6,7 +6,7 @@
* random functions for dithering.
*
* last modified:
- * $Id: dither.c,v 1.4 2002/09/13 13:08:45 menno Exp $
+ * $Id: dither.c,v 1.5 2002/10/01 21:55:49 menno Exp $
*/
#include "common.h"
@@ -14,63 +14,6 @@
#include <memory.h>
#include "dither.h"
-
-static const uint8_t Parity [256] = { // parity- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0
-};
-
-static uint32_t __r1 = 1;
-static uint32_t __r2 = 1;
-
-
-/*
- * This is a simple random number generator with good quality for audio purposes.
- * It consists of two polycounters with opposite rotation direction and different
- * periods. The periods are coprime, so the total period is the product of both.
- *
- * -------------------------------------------------------------------------------------------------
- * +-> |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0|
- * | -------------------------------------------------------------------------------------------------
- * | | | | | | |
- * | +--+--+--+-XOR-+--------+
- * | |
- * +--------------------------------------------------------------------------------------+
- *
- * -------------------------------------------------------------------------------------------------
- * |31:30:29:28:27:26:25:24:23:22:21:20:19:18:17:16:15:14:13:12:11:10: 9: 8: 7: 6: 5: 4: 3: 2: 1: 0| <-+
- * ------------------------------------------------------------------------------------------------- |
- * | | | | |
- * +--+----XOR----+--+ |
- * | |
- * +----------------------------------------------------------------------------------------+
- *
- *
- * The first has an period of 3*5*17*257*65537, the second of 7*47*73*178481,
- * which gives a period of 18.410.713.077.675.721.215. The result is the
- * XORed values of both generators.
- */
-
-
-uint32_t
-random_int ( void )
-{- uint32_t t1, t2, t3, t4;
-
- t3 = t1 = __r1; t4 = t2 = __r2; // Parity calculation is done via table lookup, this is also available
- t1 &= 0xF5; t2 >>= 25; // on CPUs without parity, can be implemented in C and avoid unpredictable
- t1 = Parity [t1]; t2 &= 0x63; // jumps and slow rotate through the carry flag operations.
- t1 <<= 31; t2 = Parity [t2];
-
- return (__r1 = (t3 >> 1) | t1 ) ^ (__r2 = (t4 + t4) | t2 );
-}
-
double
--- a/libfaad/pns.c
+++ b/libfaad/pns.c
@@ -16,7 +16,7 @@
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
-** $Id: pns.c,v 1.17 2002/09/13 13:08:45 menno Exp $
+** $Id: pns.c,v 1.18 2002/10/01 21:55:49 menno Exp $
**/
#include "common.h"
@@ -24,32 +24,6 @@
#include "pns.h"
-static const uint8_t Parity [256] = { // parity- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,
- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,
- 1,0,0,1,0,1,1,0,0,1,1,0,1,0,0,1,0,1,1,0,1,0,0,1,1,0,0,1,0,1,1,0
-};
-
-static int32_t __r1 = 1;
-static int32_t __r2 = 1;
-
-static INLINE int32_t random2()
-{- int32_t t1, t2, t3, t4;
-
- t3 = t1 = __r1; t4 = t2 = __r2; // Parity calculation is done via table lookup, this is also available
- t1 &= 0xF5; t2 >>= 25; // on CPUs without parity, can be implemented in C and avoid unpredictable
- t1 = Parity [t1]; t2 &= 0x63; // jumps and slow rotate through the carry flag operations.
- t1 <<= 31; t2 = Parity [t2];
-
- return (__r1 = (t3 >> 1) | t1 ) ^ (__r2 = (t4 + t4) | t2 );
-}
-
#ifdef FIXED_POINT
#define DIV(A, B) (((int64_t)A << COEF_BITS)/B)
@@ -108,7 +82,7 @@
for (i = 0; i < size; i++)
{- real_t tmp = scale*(real_t)random2();
+ real_t tmp = scale*(real_t)(int32_t)random_int();
spec[i] = tmp;
energy += tmp*tmp;
}
@@ -126,7 +100,7 @@
for (i = 0; i < size; i++)
{- real_t tmp = ISQRT_MEAN_NRG * random2();
+ real_t tmp = ISQRT_MEAN_NRG * (int32_t)random_int();
tmp = MUL_C_C(COEF_CONST(1)/size, tmp);
energy += MUL_C_C(tmp,tmp);