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Add a fancy 64-bit pseudo random number generator -- thanks to its developers

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This commit is contained in:
Mike Brady
2016-09-07 09:05:43 +01:00
parent 06fce76ce4
commit 4e4edf9909
5 changed files with 266 additions and 8 deletions
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Makefile.am
+1 -1
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@@ -1,7 +1,7 @@
SUBDIRS = man
bin_PROGRAMS = shairport-sync
shairport_sync_SOURCES = shairport.c rtsp.c mdns.c mdns_external.c common.c rtp.c player.c alac.c audio.c
shairport_sync_SOURCES = shairport.c rtsp.c mdns.c mdns_external.c common.c rtp.c player.c alac.c audio.c mt19937-64.c
AM_CFLAGS = -Wno-multichar -DSYSCONFDIR=\"$(sysconfdir)\"
AM_CPPFLAGS = -Wno-multichar -DSYSCONFDIR=\"$(sysconfdir)\"
mt19937-64.c
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@@ -0,0 +1,168 @@
/*
A C-program for MT19937-64 (2014/2/23 version).
Coded by Takuji Nishimura and Makoto Matsumoto.
This is a 64-bit version of Mersenne Twister pseudorandom number
generator.
Before using, initialize the state by using init_genrand64(seed)
or init_by_array64(init_key, key_length).
Copyright (C) 2004, 2014, Makoto Matsumoto and Takuji Nishimura,
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The names of its contributors may not be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
References:
T. Nishimura, ``Tables of 64-bit Mersenne Twisters''
ACM Transactions on Modeling and
Computer Simulation 10. (2000) 348--357.
M. Matsumoto and T. Nishimura,
``Mersenne Twister: a 623-dimensionally equidistributed
uniform pseudorandom number generator''
ACM Transactions on Modeling and
Computer Simulation 8. (Jan. 1998) 3--30.
Any feedback is very welcome.
http://www.math.hiroshima-u.ac.jp/~m-mat/MT/emt.html
email: m-mat @ math.sci.hiroshima-u.ac.jp (remove spaces)
*/
#include <stdio.h>
#include "mt64.h"
#define NN 312
#define MM 156
#define MATRIX_A UINT64_C(0xB5026F5AA96619E9)
#define UM UINT64_C(0xFFFFFFFF80000000) /* Most significant 33 bits */
#define LM UINT64_C(0x7FFFFFFF) /* Least significant 31 bits */
/* The array for the state vector */
static uint64_t mt[NN];
/* mti==NN+1 means mt[NN] is not initialized */
static int mti=NN+1;
/* initializes mt[NN] with a seed */
void init_genrand64(uint64_t seed)
{
mt[0] = seed;
for (mti=1; mti<NN; mti++)
mt[mti] = (UINT64_C(6364136223846793005) * (mt[mti-1] ^ (mt[mti-1] >> 62)) + mti);
}
/* initialize by an array with array-length */
/* init_key is the array for initializing keys */
/* key_length is its length */
void init_by_array64(uint64_t init_key[],
uint64_t key_length)
{
unsigned int i, j;
uint64_t k;
init_genrand64(UINT64_C(19650218));
i=1; j=0;
k = (NN>key_length ? NN : key_length);
for (; k; k--) {
mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 62)) * UINT64_C(3935559000370003845)))
+ init_key[j] + j; /* non linear */
i++; j++;
if (i>=NN) { mt[0] = mt[NN-1]; i=1; }
if (j>=key_length) j=0;
}
for (k=NN-1; k; k--) {
mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 62)) * UINT64_C(2862933555777941757)))
- i; /* non linear */
i++;
if (i>=NN) { mt[0] = mt[NN-1]; i=1; }
}
mt[0] = UINT64_C(1) << 63; /* MSB is 1; assuring non-zero initial array */
}
/* generates a random number on [0, 2^64-1]-interval */
uint64_t genrand64_int64(void)
{
int i;
uint64_t x;
static uint64_t mag01[2]={UINT64_C(0), MATRIX_A};
if (mti >= NN) { /* generate NN words at one time */
/* if init_genrand64() has not been called, */
/* a default initial seed is used */
if (mti == NN+1)
init_genrand64(UINT64_C(5489));
for (i=0;i<NN-MM;i++) {
x = (mt[i]&UM)|(mt[i+1]&LM);
mt[i] = mt[i+MM] ^ (x>>1) ^ mag01[(int)(x&UINT64_C(1))];
}
for (;i<NN-1;i++) {
x = (mt[i]&UM)|(mt[i+1]&LM);
mt[i] = mt[i+(MM-NN)] ^ (x>>1) ^ mag01[(int)(x&UINT64_C(1))];
}
x = (mt[NN-1]&UM)|(mt[0]&LM);
mt[NN-1] = mt[MM-1] ^ (x>>1) ^ mag01[(int)(x&UINT64_C(1))];
mti = 0;
}
x = mt[mti++];
x ^= (x >> 29) & UINT64_C(0x5555555555555555);
x ^= (x << 17) & UINT64_C(0x71D67FFFEDA60000);
x ^= (x << 37) & UINT64_C(0xFFF7EEE000000000);
x ^= (x >> 43);
return x;
}
/* generates a random number on [0, 2^63-1]-interval */
int64_t genrand64_int63(void)
{
return (int64_t)(genrand64_int64() >> 1);
}
/* generates a random number on [0,1]-real-interval */
double genrand64_real1(void)
{
return (genrand64_int64() >> 11) * (1.0/9007199254740991.0);
}
/* generates a random number on [0,1)-real-interval */
double genrand64_real2(void)
{
return (genrand64_int64() >> 11) * (1.0/9007199254740992.0);
}
/* generates a random number on (0,1)-real-interval */
double genrand64_real3(void)
{
return ((genrand64_int64() >> 12) + 0.5) * (1.0/4503599627370496.0);
}
mt64.h
+81
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@@ -0,0 +1,81 @@
/*
A C-program for MT19937-64 (2014/2/23 version).
Coded by Takuji Nishimura and Makoto Matsumoto.
This is a 64-bit version of Mersenne Twister pseudorandom number
generator.
Before using, initialize the state by using init_genrand64(seed)
or init_by_array64(init_key, key_length).
Copyright (C) 2004, 2014, Makoto Matsumoto and Takuji Nishimura,
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The names of its contributors may not be used to endorse or promote
products derived from this software without specific prior written
permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
References:
T. Nishimura, ``Tables of 64-bit Mersenne Twisters''
ACM Transactions on Modeling and
Computer Simulation 10. (2000) 348--357.
M. Matsumoto and T. Nishimura,
``Mersenne Twister: a 623-dimensionally equidistributed
uniform pseudorandom number generator''
ACM Transactions on Modeling and
Computer Simulation 8. (Jan. 1998) 3--30.
Any feedback is very welcome.
http://www.math.hiroshima-u.ac.jp/~m-mat/MT/emt.html
email: m-mat @ math.sci.hiroshima-u.ac.jp (remove spaces)
*/
#include <inttypes.h>
/* initializes mt[NN] with a seed */
void init_genrand64(uint64_t seed);
/* initialize by an array with array-length */
/* init_key is the array for initializing keys */
/* key_length is its length */
void init_by_array64(uint64_t init_key[],
uint64_t key_length);
/* generates a random number on [0, 2^64-1]-interval */
uint64_t genrand64_int64(void);
/* generates a random number on [0, 2^63-1]-interval */
int64_t genrand64_int63(void);
/* generates a random number on [0,1]-real-interval */
double genrand64_real1(void);
/* generates a random number on [0,1)-real-interval */
double genrand64_real2(void);
/* generates a random number on (0,1)-real-interval */
double genrand64_real3(void);
player.c
+7 -7
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@@ -68,6 +68,7 @@
#include "alac.h"
#include "apple_alac.h"
#include "mt64.h"
// parameters from the source
static unsigned char *aesiv;
@@ -583,13 +584,12 @@ int32_t rand_in_range(int32_t exclusive_range_limit) {
}
int64_t rand_in_range_64(int64_t exclusive_range_limit) {
static uint64_t lcg_prev = 12345;
// returns a pseudo random integer in the range 0 to (exclusive_range_limit-1) inclusive
int64_t sp = lcg_prev;
int64_t rl = exclusive_range_limit;
lcg_prev = lcg_prev * 69069 + 3; // crappy psrg
sp = sp*rl; // 64 bit calculation. INtersting part if above the 32 rightmost bits;
return sp;
// this is a call to a 64-bit pseudo-random number generator
// from the archive downloaded http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/mt19937-64stdint.tgz
// from http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt64.html
return genrand64_int63() % exclusive_range_limit;
}
static inline int32_t dithered_vol_32(int32_t sample, int output_precision) {
shairport.c
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@@ -54,6 +54,7 @@
#include "rtsp.h"
#include "rtp.h"
#include "mdns.h"
#include "mt64.h" // 64-bit prng
#include <libdaemon/dfork.h>
#include <libdaemon/dsignal.h>
@@ -778,6 +779,14 @@ int main(int argc, char **argv) {
#ifdef HAVE_APPLE_ALAC
config.decoders_supported += 1<<decoder_apple_alac;
#endif
// here, initialise the 64-bit random number generator
// from mt19937-64test.c in the archive downloaded http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/mt19937-64stdint.tgz
// from http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt64.html
uint64_t init[4]={UINT64_C(0x12345), UINT64_C(0x23456), UINT64_C(0x34567), UINT64_C(0x45678)}, length=4;
init_by_array64(init, length);
/* Check if we are called with -V or --version parameter */
if (argc >= 2 && ((strcmp(argv[1], "-V") == 0) || (strcmp(argv[1], "--version") == 0))) {