poke/alac/codec/dp_enc.c

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2023-02-12 10:13:40 +01:00
/*
* Copyright (c) 2011 Apple Inc. All rights reserved.
*
* @APPLE_APACHE_LICENSE_HEADER_START@
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @APPLE_APACHE_LICENSE_HEADER_END@
*/
/*
File: dp_enc.c
Contains: Dynamic Predictor encode routines
Copyright: (c) 2001-2011 Apple, Inc.
*/
#include "dplib.h"
#include <string.h>
#if __GNUC__
#define ALWAYS_INLINE __attribute__((always_inline))
#else
#define ALWAYS_INLINE
#endif
#if TARGET_CPU_PPC && (__MWERKS__ >= 0x3200)
// align loops to a 16 byte boundary to make the G5 happy
#pragma function_align 16
#define LOOP_ALIGN asm { align 16 }
#else
#define LOOP_ALIGN
#endif
void init_coefs( int16_t * coefs, uint32_t denshift, int32_t numPairs )
{
int32_t k;
int32_t den = 1 << denshift;
coefs[0] = (AINIT * den) >> 4;
coefs[1] = (BINIT * den) >> 4;
coefs[2] = (CINIT * den) >> 4;
for ( k = 3; k < numPairs; k++ )
coefs[k] = 0;
}
void copy_coefs( int16_t * srcCoefs, int16_t * dstCoefs, int32_t numPairs )
{
int32_t k;
for ( k = 0; k < numPairs; k++ )
dstCoefs[k] = srcCoefs[k];
}
static inline int32_t ALWAYS_INLINE sign_of_int( int32_t i )
{
int32_t negishift;
negishift = ((uint32_t)-i) >> 31;
return negishift | (i >> 31);
}
void pc_block( int32_t * in, int32_t * pc1, int32_t num, int16_t * coefs, int32_t numactive, uint32_t chanbits, uint32_t denshift )
{
register int16_t a0, a1, a2, a3;
register int32_t b0, b1, b2, b3;
int32_t j, k, lim;
int32_t * pin;
int32_t sum1, dd;
int32_t sg, sgn;
int32_t top;
int32_t del, del0;
uint32_t chanshift = 32 - chanbits;
int32_t denhalf = 1 << (denshift - 1);
pc1[0] = in[0];
if ( numactive == 0 )
{
// just copy if numactive == 0 (but don't bother if in/out pointers the same)
if ( (num > 1) && (in != pc1) )
memcpy( &pc1[1], &in[1], (num - 1) * sizeof(int32_t) );
return;
}
if ( numactive == 31 )
{
// short-circuit if numactive == 31
for( j = 1; j < num; j++ )
{
del = in[j] - in[j-1];
pc1[j] = (del << chanshift) >> chanshift;
}
return;
}
for ( j = 1; j <= numactive; j++ )
{
del = in[j] - in[j-1];
pc1[j] = (del << chanshift) >> chanshift;
}
lim = numactive + 1;
if ( numactive == 4 )
{
// optimization for numactive == 4
a0 = coefs[0];
a1 = coefs[1];
a2 = coefs[2];
a3 = coefs[3];
for ( j = lim; j < num; j++ )
{
LOOP_ALIGN
top = in[j - lim];
pin = in + j - 1;
b0 = top - pin[0];
b1 = top - pin[-1];
b2 = top - pin[-2];
b3 = top - pin[-3];
sum1 = (denhalf - a0 * b0 - a1 * b1 - a2 * b2 - a3 * b3) >> denshift;
del = in[j] - top - sum1;
del = (del << chanshift) >> chanshift;
pc1[j] = del;
del0 = del;
sg = sign_of_int(del);
if ( sg > 0 )
{
sgn = sign_of_int( b3 );
a3 -= sgn;
del0 -= (4 - 3) * ((sgn * b3) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b2 );
a2 -= sgn;
del0 -= (4 - 2) * ((sgn * b2) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b1 );
a1 -= sgn;
del0 -= (4 - 1) * ((sgn * b1) >> denshift);
if ( del0 <= 0 )
continue;
a0 -= sign_of_int( b0 );
}
else if ( sg < 0 )
{
// note: to avoid unnecessary negations, we flip the value of "sgn"
sgn = -sign_of_int( b3 );
a3 -= sgn;
del0 -= (4 - 3) * ((sgn * b3) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b2 );
a2 -= sgn;
del0 -= (4 - 2) * ((sgn * b2) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b1 );
a1 -= sgn;
del0 -= (4 - 1) * ((sgn * b1) >> denshift);
if ( del0 >= 0 )
continue;
a0 += sign_of_int( b0 );
}
}
coefs[0] = a0;
coefs[1] = a1;
coefs[2] = a2;
coefs[3] = a3;
}
else if ( numactive == 8 )
{
// optimization for numactive == 8
register int16_t a4, a5, a6, a7;
register int32_t b4, b5, b6, b7;
a0 = coefs[0];
a1 = coefs[1];
a2 = coefs[2];
a3 = coefs[3];
a4 = coefs[4];
a5 = coefs[5];
a6 = coefs[6];
a7 = coefs[7];
for ( j = lim; j < num; j++ )
{
LOOP_ALIGN
top = in[j - lim];
pin = in + j - 1;
b0 = top - (*pin--);
b1 = top - (*pin--);
b2 = top - (*pin--);
b3 = top - (*pin--);
b4 = top - (*pin--);
b5 = top - (*pin--);
b6 = top - (*pin--);
b7 = top - (*pin);
pin += 8;
sum1 = (denhalf - a0 * b0 - a1 * b1 - a2 * b2 - a3 * b3
- a4 * b4 - a5 * b5 - a6 * b6 - a7 * b7) >> denshift;
del = in[j] - top - sum1;
del = (del << chanshift) >> chanshift;
pc1[j] = del;
del0 = del;
sg = sign_of_int(del);
if ( sg > 0 )
{
sgn = sign_of_int( b7 );
a7 -= sgn;
del0 -= 1 * ((sgn * b7) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b6 );
a6 -= sgn;
del0 -= 2 * ((sgn * b6) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b5 );
a5 -= sgn;
del0 -= 3 * ((sgn * b5) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b4 );
a4 -= sgn;
del0 -= 4 * ((sgn * b4) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b3 );
a3 -= sgn;
del0 -= 5 * ((sgn * b3) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b2 );
a2 -= sgn;
del0 -= 6 * ((sgn * b2) >> denshift);
if ( del0 <= 0 )
continue;
sgn = sign_of_int( b1 );
a1 -= sgn;
del0 -= 7 * ((sgn * b1) >> denshift);
if ( del0 <= 0 )
continue;
a0 -= sign_of_int( b0 );
}
else if ( sg < 0 )
{
// note: to avoid unnecessary negations, we flip the value of "sgn"
sgn = -sign_of_int( b7 );
a7 -= sgn;
del0 -= 1 * ((sgn * b7) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b6 );
a6 -= sgn;
del0 -= 2 * ((sgn * b6) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b5 );
a5 -= sgn;
del0 -= 3 * ((sgn * b5) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b4 );
a4 -= sgn;
del0 -= 4 * ((sgn * b4) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b3 );
a3 -= sgn;
del0 -= 5 * ((sgn * b3) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b2 );
a2 -= sgn;
del0 -= 6 * ((sgn * b2) >> denshift);
if ( del0 >= 0 )
continue;
sgn = -sign_of_int( b1 );
a1 -= sgn;
del0 -= 7 * ((sgn * b1) >> denshift);
if ( del0 >= 0 )
continue;
a0 += sign_of_int( b0 );
}
}
coefs[0] = a0;
coefs[1] = a1;
coefs[2] = a2;
coefs[3] = a3;
coefs[4] = a4;
coefs[5] = a5;
coefs[6] = a6;
coefs[7] = a7;
}
else
{
//pc_block_general:
// general case
for ( j = lim; j < num; j++ )
{
LOOP_ALIGN
top = in[j - lim];
pin = in + j - 1;
sum1 = 0;
for ( k = 0; k < numactive; k++ )
sum1 -= coefs[k] * (top - pin[-k]);
del = in[j] - top - ((sum1 + denhalf) >> denshift);
del = (del << chanshift) >> chanshift;
pc1[j] = del;
del0 = del;
sg = sign_of_int( del );
if ( sg > 0 )
{
for ( k = (numactive - 1); k >= 0; k-- )
{
dd = top - pin[-k];
sgn = sign_of_int( dd );
coefs[k] -= sgn;
del0 -= (numactive - k) * ((sgn * dd) >> denshift);
if ( del0 <= 0 )
break;
}
}
else if ( sg < 0 )
{
for ( k = (numactive - 1); k >= 0; k-- )
{
dd = top - pin[-k];
sgn = sign_of_int( dd );
coefs[k] += sgn;
del0 -= (numactive - k) * ((-sgn * dd) >> denshift);
if ( del0 >= 0 )
break;
}
}
}
}
}