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sm64pc/tools/audiofile-0.3.6/libaudiofile/alac/dp_dec.c
Jan200101 e87c070517
merge PC port onto the decompile
2020-05-07 20:21:22 +02:00

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/*
* 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_dec.c
Contains: Dynamic Predictor decode 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
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 unpc_block( int32_t * pc1, int32_t * out, 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 sum1, sg, sgn, top, dd;
int32_t * pout;
int32_t del, del0;
uint32_t chanshift = 32 - chanbits;
int32_t denhalf = 1<<(denshift-1);
out[0] = pc1[0];
if ( numactive == 0 )
{
// just copy if numactive == 0 (but don't bother if in/out pointers the same)
if ( (num > 1) && (pc1 != out) )
memcpy( &out[1], &pc1[1], (num - 1) * sizeof(int32_t) );
return;
}
if ( numactive == 31 )
{
// short-circuit if numactive == 31
int32_t prev;
/* this code is written such that the in/out buffers can be the same
to conserve buffer space on embedded devices like the iPod
(original code)
for ( j = 1; j < num; j++ )
del = pc1[j] + out[j-1];
out[j] = (del << chanshift) >> chanshift;
*/
prev = out[0];
for ( j = 1; j < num; j++ )
{
del = pc1[j] + prev;
prev = (del << chanshift) >> chanshift;
out[j] = prev;
}
return;
}
for ( j = 1; j <= numactive; j++ )
{
del = pc1[j] + out[j-1];
out[j] = (del << chanshift) >> chanshift;
}
lim = numactive + 1;
if ( numactive == 4 )
{
// optimization for numactive == 4
register int16_t a0, a1, a2, a3;
register int32_t b0, b1, b2, b3;
a0 = coefs[0];
a1 = coefs[1];
a2 = coefs[2];
a3 = coefs[3];
for ( j = lim; j < num; j++ )
{
LOOP_ALIGN
top = out[j - lim];
pout = out + j - 1;
b0 = top - pout[0];
b1 = top - pout[-1];
b2 = top - pout[-2];
b3 = top - pout[-3];
sum1 = (denhalf - a0 * b0 - a1 * b1 - a2 * b2 - a3 * b3) >> denshift;
del = pc1[j];
del0 = del;
sg = sign_of_int(del);
del += top + sum1;
out[j] = (del << chanshift) >> chanshift;
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 )
{
register int16_t a4, a5, a6, a7;
register int32_t b4, b5, b6, b7;
// optimization for numactive == 8
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 = out[j - lim];
pout = out + j - 1;
b0 = top - (*pout--);
b1 = top - (*pout--);
b2 = top - (*pout--);
b3 = top - (*pout--);
b4 = top - (*pout--);
b5 = top - (*pout--);
b6 = top - (*pout--);
b7 = top - (*pout);
pout += 8;
sum1 = (denhalf - a0 * b0 - a1 * b1 - a2 * b2 - a3 * b3
- a4 * b4 - a5 * b5 - a6 * b6 - a7 * b7) >> denshift;
del = pc1[j];
del0 = del;
sg = sign_of_int(del);
del += top + sum1;
out[j] = (del << chanshift) >> chanshift;
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
{
// general case
for ( j = lim; j < num; j++ )
{
LOOP_ALIGN
sum1 = 0;
pout = out + j - 1;
top = out[j-lim];
for ( k = 0; k < numactive; k++ )
sum1 += coefs[k] * (pout[-k] - top);
del = pc1[j];
del0 = del;
sg = sign_of_int( del );
del += top + ((sum1 + denhalf) >> denshift);
out[j] = (del << chanshift) >> chanshift;
if ( sg > 0 )
{
for ( k = (numactive - 1); k >= 0; k-- )
{
dd = top - pout[-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 - pout[-k];
sgn = sign_of_int( dd );
coefs[k] += sgn;
del0 -= (numactive - k) * ((-sgn * dd) >> denshift);
if ( del0 >= 0 )
break;
}
}
}
}
}
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