ref: 8c48c943e7c082b4330061e74ce85547253de301
dir: /vp8/common/x86/boolcoder.cxx/
/*
* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/* Arithmetic bool coder with largish probability range.
Timothy S Murphy 6 August 2004 */
#include <assert.h>
#include <math.h>
#include "bool_coder.h"
#if tim_vp8
extern "C" {
# include "VP8cx/treewriter.h"
}
#endif
int_types::~int_types() {}
void bool_coder_spec::check_prec() const {
assert( w && (r==Up || w > 1) && w < 24 && (ebias || w < 17));
}
bool bool_coder_spec::float_init( uint Ebits, uint Mbits) {
uint b = (ebits = Ebits) + (mbits = Mbits);
if( b) {
assert( ebits < 6 && w + mbits < 31);
assert( ebits + mbits < sizeof(Index) * 8);
ebias = (1 << ebits) + 1 + mbits;
mmask = (1 << mbits) - 1;
max_index = ( ( half_index = 1 << b ) << 1) - 1;
} else {
ebias = 0;
max_index = 255;
half_index = 128;
}
check_prec();
return b? 1:0;
}
void bool_coder_spec::cost_init()
{
static cdouble c = -(1 << 20)/log( 2.);
FILE *f = fopen( "costs.txt", "w");
assert( f);
assert( sizeof(int) >= 4); /* for C interface */
assert( max_index <= 255); /* size of Ctbl */
uint i = 0; do {
cdouble p = ( *this)( (Index) i);
Ctbl[i] = (uint32) ( log( p) * c);
fprintf(
f, "cost( %d -> %10.7f) = %10d = %12.5f bits\n",
i, p, Ctbl[i], (double) Ctbl[i] / (1<<20)
);
} while( ++i <= max_index);
fclose( f);
}
bool_coder_spec_explicit_table::bool_coder_spec_explicit_table(
cuint16 tbl[256], Rounding rr, uint prec
)
: bool_coder_spec( prec, rr)
{
check_prec();
uint i = 0;
if( tbl)
do { Ptbl[i] = tbl[i];} while( ++i < 256);
else
do { Ptbl[i] = i << 8;} while( ++i < 256);
cost_init();
}
bool_coder_spec_exponential_table::bool_coder_spec_exponential_table(
uint x, Rounding rr, uint prec
)
: bool_coder_spec( prec, rr)
{
assert( x > 1 && x <= 16);
check_prec();
Ptbl[128] = 32768u;
Ptbl[0] = (uint16) pow( 2., 16. - x);
--x;
int i=1; do {
cdouble d = pow( .5, 1. + (1. - i/128.)*x) * 65536.;
uint16 v = (uint16) d;
if( v < i)
v = i;
Ptbl[256-i] = (uint16) ( 65536U - (Ptbl[i] = v));
} while( ++i < 128);
cost_init();
}
bool_coder_spec::bool_coder_spec( FILE *fp) {
fscanf( fp, "%d", &w);
int v;
fscanf( fp, "%d", &v);
assert( 0 <= v && v <= 2);
r = (Rounding) v;
fscanf( fp, "%d", &ebits);
fscanf( fp, "%d", &mbits);
if( float_init( ebits, mbits))
return;
int i=0; do {
uint v;
fscanf( fp, "%d", &v);
assert( 0 <=v && v <= 65535U);
Ptbl[i] = v;
} while( ++i < 256);
cost_init();
}
void bool_coder_spec::dump( FILE *fp) const {
fprintf( fp, "%d %d %d %d\n", w, (int) r, ebits, mbits);
if( ebits || mbits)
return;
int i=0; do { fprintf( fp, "%d\n", Ptbl[i]);} while( ++i < 256);
}
vp8bc_index_t bool_coder_spec::operator()( double p) const
{
if( p <= 0.)
return 0;
if( p >= 1.)
return max_index;
if( ebias) {
if( p > .5)
return max_index - ( *this)( 1. - p);
int e;
uint m = (uint) ldexp( frexp( p, &e), mbits + 2);
uint x = 1 << (mbits + 1);
assert( x <= m && m < x<<1);
if( (m = (m >> 1) + (m & 1)) >= x) {
m = x >> 1;
++e;
}
int y = 1 << ebits;
if( (e += y) >= y)
return half_index - 1;
if( e < 0)
return 0;
return (Index) ( (e << mbits) + (m & mmask));
}
cuint16 v = (uint16) (p * 65536.);
int i = 128;
int j = 128;
uint16 w;
while( w = Ptbl[i], j >>= 1) {
if( w < v)
i += j;
else if( w == v)
return (uchar) i;
else
i -= j;
}
if( w > v) {
cuint16 x = Ptbl[i-1];
if( v <= x || w - v > v - x)
--i;
} else if( w < v && i < 255) {
cuint16 x = Ptbl[i+1];
if( x <= v || x - v < v - w)
++i;
}
return (Index) i;
}
double bool_coder_spec::operator()( Index i) const {
if( !ebias)
return Ptbl[i]/65536.;
if( i >= half_index)
return 1. - ( *this)( (Index) (max_index - i));
return ldexp( (double)mantissa( i), - (int) exponent( i));
}
void bool_writer::carry() {
uchar *p = B;
assert( p > Bstart);
while( *--p == 255) { assert( p > Bstart); *p = 0;}
++*p;
}
bool_writer::bool_writer( c_spec& s, uchar *Dest, size_t Len)
: bool_coder( s),
Bstart( Dest),
Bend( Len? Dest+Len : 0),
B( Dest)
{
assert( Dest);
reset();
}
bool_writer::~bool_writer() { flush();}
#if 1
extern "C" { int bc_v = 0;}
#else
# define bc_v 0
#endif
void bool_writer::raw( bool value, uint32 s) {
uint32 L = Low;
assert( Range >= min_range && Range <= spec.max_range());
assert( !is_toast && s && s < Range);
if( bc_v) printf(
"Writing a %d, B %x Low %x Range %x s %x blag %d ...\n",
value? 1:0, B-Bstart, Low, Range, s, bit_lag
);
if( value) {
L += s;
s = Range - s;
} else
s -= rinc;
if( s < min_range) {
int ct = bit_lag; do {
if( !--ct) {
ct = 8;
if( L & (1 << 31))
carry();
assert( !Bend || B < Bend);
*B++ = (uchar) (L >> 23);
L &= (1<<23) - 1;
}
} while( L += L, (s += s + rinc) < min_range);
bit_lag = ct;
}
Low = L;
Range = s;
if( bc_v)
printf(
"...done, B %x Low %x Range %x blag %d \n",
B-Bstart, Low, Range, bit_lag
);
}
bool_writer& bool_writer::flush() {
if( is_toast)
return *this;
int b = bit_lag;
uint32 L = Low;
assert( b);
if( L & (1 << (32 - b)))
carry();
L <<= b & 7;
b >>= 3;
while( --b >= 0)
L <<= 8;
b = 4;
assert( !Bend || B + 4 <= Bend);
do {
*B++ = (uchar) (L >> 24);
L <<= 8;
} while( --b);
is_toast = 1;
return *this;
}
bool_reader::bool_reader( c_spec& s, cuchar *src, size_t Len)
: bool_coder( s),
Bstart( src),
B( src),
Bend( Len? src+Len : 0),
shf( 32 - s.w),
bct( 8)
{
int i = 4; do { Low <<= 8; Low |= *B++;} while( --i);
}
bool bool_reader::raw( uint32 s) {
bool val = 0;
uint32 L = Low;
cuint32 S = s << shf;
assert( Range >= min_range && Range <= spec.max_range());
assert( s && s < Range && (L >> shf) < Range);
if( bc_v)
printf(
"Reading, B %x Low %x Range %x s %x bct %d ...\n",
B-Bstart, Low, Range, s, bct
);
if( L >= S) {
L -= S;
s = Range - s;
assert( L < (s << shf));
val = 1;
} else
s -= rinc;
if( s < min_range) {
int ct = bct;
do {
assert( ~L & (1 << 31));
L += L;
if( !--ct) {
ct = 8;
if( !Bend || B < Bend)
L |= *B++;
}
} while( (s += s + rinc) < min_range);
bct = ct;
}
Low = L;
Range = s;
if( bc_v)
printf(
"...done, val %d B %x Low %x Range %x bct %d\n",
val? 1:0, B-Bstart, Low, Range, bct
);
return val;
}
/* C interfaces */
// spec interface
struct NS : bool_coder_namespace {
static Rounding r( vp8bc_c_prec *p, Rounding rr =down_full) {
return p? (Rounding) p->r : rr;
}
};
bool_coder_spec *vp8bc_vp6spec() {
return new bool_coder_spec_explicit_table( 0, bool_coder_namespace::Down, 8);
}
bool_coder_spec *vp8bc_float_spec(
unsigned int Ebits, unsigned int Mbits, vp8bc_c_prec *p
) {
return new bool_coder_spec_float( Ebits, Mbits, NS::r( p), p? p->prec : 12);
}
bool_coder_spec *vp8bc_literal_spec(
const unsigned short m[256], vp8bc_c_prec *p
) {
return new bool_coder_spec_explicit_table( m, NS::r( p), p? p->prec : 16);
}
bool_coder_spec *vp8bc_exponential_spec( unsigned int x, vp8bc_c_prec *p)
{
return new bool_coder_spec_exponential_table( x, NS::r( p), p? p->prec : 16);
}
bool_coder_spec *vp8bc_spec_from_file( FILE *fp) {
return new bool_coder_spec( fp);
}
void vp8bc_destroy_spec( c_bool_coder_spec *p) { delete p;}
void vp8bc_spec_to_file( c_bool_coder_spec *p, FILE *fp) { p->dump( fp);}
vp8bc_index_t vp8bc_index( c_bool_coder_spec *p, double x) {
return ( *p)( x);
}
vp8bc_index_t vp8bc_index_from_counts(
c_bool_coder_spec *p, unsigned int L, unsigned int R
) {
return ( *p)( (R += L)? (double) L/R : .5);
}
double vp8bc_probability( c_bool_coder_spec *p, vp8bc_index_t i) {
return ( *p)( i);
}
vp8bc_index_t vp8bc_complement( c_bool_coder_spec *p, vp8bc_index_t i) {
return p->complement( i);
}
unsigned int vp8bc_cost_zero( c_bool_coder_spec *p, vp8bc_index_t i) {
return p->cost_zero( i);
}
unsigned int vp8bc_cost_one( c_bool_coder_spec *p, vp8bc_index_t i) {
return p->cost_one( i);
}
unsigned int vp8bc_cost_bit( c_bool_coder_spec *p, vp8bc_index_t i, int v) {
return p->cost_bit( i, v);
}
#if tim_vp8
extern "C" int tok_verbose;
# define dbg_l 1000000
static vp8bc_index_t dbg_i [dbg_l];
static char dbg_v [dbg_l];
static size_t dbg_w = 0, dbg_r = 0;
#endif
// writer interface
bool_writer *vp8bc_create_writer(
c_bool_coder_spec *p, unsigned char *D, size_t L
) {
return new bool_writer( *p, D, L);
}
size_t vp8bc_destroy_writer( bool_writer *p) {
const size_t s = p->flush().bytes_written();
delete p;
return s;
}
void vp8bc_write_bool( bool_writer *p, int v, vp8bc_index_t i)
{
# if tim_vp8
// bc_v = dbg_w < 10;
if( bc_v = tok_verbose)
printf( " writing %d at prob %d\n", v? 1:0, i);
accum_entropy_bc( &p->Spec(), i, v);
( *p)( i, (bool) v);
if( dbg_w < dbg_l) {
dbg_i [dbg_w] = i;
dbg_v [dbg_w++] = v? 1:0;
}
# else
( *p)( i, (bool) v);
# endif
}
void vp8bc_write_bits( bool_writer *p, unsigned int v, int n)
{
# if tim_vp8
{
c_bool_coder_spec * const s = & p->Spec();
const vp8bc_index_t i = s->half_index();
int m = n;
while( --m >= 0)
accum_entropy_bc( s, i, (v>>m) & 1);
}
# endif
p->write_bits( n, v);
}
c_bool_coder_spec *vp8bc_writer_spec( c_bool_writer *w) { return & w->Spec();}
// reader interface
bool_reader *vp8bc_create_reader(
c_bool_coder_spec *p, const unsigned char *S, size_t L
) {
return new bool_reader( *p, S, L);
}
void vp8bc_destroy_reader( bool_reader * p) { delete p;}
int vp8bc_read_bool( bool_reader *p, vp8bc_index_t i)
{
# if tim_vp8
// bc_v = dbg_r < 10;
bc_v = tok_verbose;
const int v = ( *p)( i)? 1:0;
if( tok_verbose)
printf( " reading %d at prob %d\n", v, i);
if( dbg_r < dbg_l) {
assert( dbg_r <= dbg_w);
if( i != dbg_i[dbg_r] || v != dbg_v[dbg_r]) {
printf(
"Position %d: INCORRECTLY READING %d prob %d, wrote %d prob %d\n",
dbg_r, v, i, dbg_v[dbg_r], dbg_i[dbg_r]
);
}
++dbg_r;
}
return v;
# else
return ( *p)( i)? 1:0;
# endif
}
unsigned int vp8bc_read_bits( bool_reader *p, int n) { return p->read_bits( n);}
c_bool_coder_spec *vp8bc_reader_spec( c_bool_reader *r) { return & r->Spec();}
#undef bc_v