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/* ***** BEGIN LICENSE BLOCK *****
* Version: RCSL 1.0/RPSL 1.0
*
* Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
*
* The contents of this file, and the files included with this file, are
* subject to the current version of the RealNetworks Public Source License
* Version 1.0 (the "RPSL") available at
* http://www.helixcommunity.org/content/rpsl unless you have licensed
* the file under the RealNetworks Community Source License Version 1.0
* (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
* in which case the RCSL will apply. You may also obtain the license terms
* directly from RealNetworks. You may not use this file except in
* compliance with the RPSL or, if you have a valid RCSL with RealNetworks
* applicable to this file, the RCSL. Please see the applicable RPSL or
* RCSL for the rights, obligations and limitations governing use of the
* contents of the file.
*
* This file is part of the Helix DNA Technology. RealNetworks is the
* developer of the Original Code and owns the copyrights in the portions
* it created.
*
* This file, and the files included with this file, is distributed and made
* available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
*
* Technology Compatibility Kit Test Suite(s) Location:
* http://www.helixcommunity.org/content/tck
*
* Contributor(s):
*
* ***** END LICENSE BLOCK ***** */
/**************************************************************************************
* Fixed-point MP3 decoder
* Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com)
* June 2003
*
* dct32.c - optimized implementations of 32-point DCT for matrixing stage of
* polyphase filter
**************************************************************************************/
#include "coder.h"
#include "assembly.h"
#define COS0_0 0x4013c251 /* Q31 */
#define COS0_1 0x40b345bd /* Q31 */
#define COS0_2 0x41fa2d6d /* Q31 */
#define COS0_3 0x43f93421 /* Q31 */
#define COS0_4 0x46cc1bc4 /* Q31 */
#define COS0_5 0x4a9d9cf0 /* Q31 */
#define COS0_6 0x4fae3711 /* Q31 */
#define COS0_7 0x56601ea7 /* Q31 */
#define COS0_8 0x5f4cf6eb /* Q31 */
#define COS0_9 0x6b6fcf26 /* Q31 */
#define COS0_10 0x7c7d1db3 /* Q31 */
#define COS0_11 0x4ad81a97 /* Q30 */
#define COS0_12 0x5efc8d96 /* Q30 */
#define COS0_13 0x41d95790 /* Q29 */
#define COS0_14 0x6d0b20cf /* Q29 */
#define COS0_15 0x518522fb /* Q27 */
#define COS1_0 0x404f4672 /* Q31 */
#define COS1_1 0x42e13c10 /* Q31 */
#define COS1_2 0x48919f44 /* Q31 */
#define COS1_3 0x52cb0e63 /* Q31 */
#define COS1_4 0x64e2402e /* Q31 */
#define COS1_5 0x43e224a9 /* Q30 */
#define COS1_6 0x6e3c92c1 /* Q30 */
#define COS1_7 0x519e4e04 /* Q28 */
#define COS2_0 0x4140fb46 /* Q31 */
#define COS2_1 0x4cf8de88 /* Q31 */
#define COS2_2 0x73326bbf /* Q31 */
#define COS2_3 0x52036742 /* Q29 */
#define COS3_0 0x4545e9ef /* Q31 */
#define COS3_1 0x539eba45 /* Q30 */
#define COS4_0 0x5a82799a /* Q31 */
// faster in ROM
static const int dcttab[48] = {
/* first pass */
COS0_0, COS0_15, COS1_0, /* 31, 27, 31 */
COS0_1, COS0_14, COS1_1, /* 31, 29, 31 */
COS0_2, COS0_13, COS1_2, /* 31, 29, 31 */
COS0_3, COS0_12, COS1_3, /* 31, 30, 31 */
COS0_4, COS0_11, COS1_4, /* 31, 30, 31 */
COS0_5, COS0_10, COS1_5, /* 31, 31, 30 */
COS0_6, COS0_9, COS1_6, /* 31, 31, 30 */
COS0_7, COS0_8, COS1_7, /* 31, 31, 28 */
/* second pass */
COS2_0, COS2_3, COS3_0, /* 31, 29, 31 */
COS2_1, COS2_2, COS3_1, /* 31, 31, 30 */
-COS2_0, -COS2_3, COS3_0, /* 31, 29, 31 */
-COS2_1, -COS2_2, COS3_1, /* 31, 31, 30 */
COS2_0, COS2_3, COS3_0, /* 31, 29, 31 */
COS2_1, COS2_2, COS3_1, /* 31, 31, 30 */
-COS2_0, -COS2_3, COS3_0, /* 31, 29, 31 */
-COS2_1, -COS2_2, COS3_1, /* 31, 31, 30 */
};
#define D32FP(i, s0, s1, s2) { \
a0 = buf[i]; a3 = buf[31-i]; \
a1 = buf[15-i]; a2 = buf[16+i]; \
b0 = a0 + a3; b3 = MULSHIFT32(*cptr++, a0 - a3) << (s0); \
b1 = a1 + a2; b2 = MULSHIFT32(*cptr++, a1 - a2) << (s1); \
buf[i] = b0 + b1; buf[15-i] = MULSHIFT32(*cptr, b0 - b1) << (s2); \
buf[16+i] = b2 + b3; buf[31-i] = MULSHIFT32(*cptr++, b3 - b2) << (s2); \
}
/**************************************************************************************
* Function: FDCT32
*
* Description: Ken's highly-optimized 32-point DCT (radix-4 + radix-8)
*
* Inputs: input buffer, length = 32 samples
* require at least 6 guard bits in input vector x to avoid possibility
* of overflow in internal calculations (see bbtest_imdct test app)
* buffer offset and oddblock flag for polyphase filter input buffer
* number of guard bits in input
*
* Outputs: output buffer, data copied and interleaved for polyphase filter
* no guarantees about number of guard bits in output
*
* Return: none
*
* Notes: number of muls = 4*8 + 12*4 = 80
* final stage of DCT is hardcoded to shuffle data into the proper order
* for the polyphase filterbank
* fully unrolled stage 1, for max precision (scale the 1/cos() factors
* differently, depending on magnitude)
* guard bit analysis verified by exhaustive testing of all 2^32
* combinations of max pos/max neg values in x[]
*
* TODO: code organization and optimization for ARM
* possibly interleave stereo (cut # of coef loads in half - may not have
* enough registers)
**************************************************************************************/
// about 1ms faster in RAM
/*__attribute__ ((section (".data")))*/ void FDCT32(int *buf, int *dest, int offset, int oddBlock, int gb)
{
int i, s, tmp, es;
const int *cptr = dcttab;
int a0, a1, a2, a3, a4, a5, a6, a7;
int b0, b1, b2, b3, b4, b5, b6, b7;
int *d;
/* scaling - ensure at least 6 guard bits for DCT
* (in practice this is already true 99% of time, so this code is
* almost never triggered)
*/
es = 0;
if (gb < 6) {
es = 6 - gb;
for (i = 0; i < 32; i++)
buf[i] >>= es;
}
/* first pass */
D32FP(0, 1, 5, 1);
D32FP(1, 1, 3, 1);
D32FP(2, 1, 3, 1);
D32FP(3, 1, 2, 1);
D32FP(4, 1, 2, 1);
D32FP(5, 1, 1, 2);
D32FP(6, 1, 1, 2);
D32FP(7, 1, 1, 4);
/* second pass */
for (i = 4; i > 0; i--) {
a0 = buf[0]; a7 = buf[7]; a3 = buf[3]; a4 = buf[4];
b0 = a0 + a7; b7 = MULSHIFT32(*cptr++, a0 - a7) << 1;
b3 = a3 + a4; b4 = MULSHIFT32(*cptr++, a3 - a4) << 3;
a0 = b0 + b3; a3 = MULSHIFT32(*cptr, b0 - b3) << 1;
a4 = b4 + b7; a7 = MULSHIFT32(*cptr++, b7 - b4) << 1;
a1 = buf[1]; a6 = buf[6]; a2 = buf[2]; a5 = buf[5];
b1 = a1 + a6; b6 = MULSHIFT32(*cptr++, a1 - a6) << 1;
b2 = a2 + a5; b5 = MULSHIFT32(*cptr++, a2 - a5) << 1;
a1 = b1 + b2; a2 = MULSHIFT32(*cptr, b1 - b2) << 2;
a5 = b5 + b6; a6 = MULSHIFT32(*cptr++, b6 - b5) << 2;
b0 = a0 + a1; b1 = MULSHIFT32(COS4_0, a0 - a1) << 1;
b2 = a2 + a3; b3 = MULSHIFT32(COS4_0, a3 - a2) << 1;
buf[0] = b0; buf[1] = b1;
buf[2] = b2 + b3; buf[3] = b3;
b4 = a4 + a5; b5 = MULSHIFT32(COS4_0, a4 - a5) << 1;
b6 = a6 + a7; b7 = MULSHIFT32(COS4_0, a7 - a6) << 1;
b6 += b7;
buf[4] = b4 + b6; buf[5] = b5 + b7;
buf[6] = b5 + b6; buf[7] = b7;
buf += 8;
}
buf -= 32; /* reset */
/* sample 0 - always delayed one block */
d = dest + 64*16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH);
s = buf[ 0]; d[0] = d[8] = s;
/* samples 16 to 31 */
d = dest + offset + (oddBlock ? VBUF_LENGTH : 0);
s = buf[ 1]; d[0] = d[8] = s; d += 64;
tmp = buf[25] + buf[29];
s = buf[17] + tmp; d[0] = d[8] = s; d += 64;
s = buf[ 9] + buf[13]; d[0] = d[8] = s; d += 64;
s = buf[21] + tmp; d[0] = d[8] = s; d += 64;
tmp = buf[29] + buf[27];
s = buf[ 5]; d[0] = d[8] = s; d += 64;
s = buf[21] + tmp; d[0] = d[8] = s; d += 64;
s = buf[13] + buf[11]; d[0] = d[8] = s; d += 64;
s = buf[19] + tmp; d[0] = d[8] = s; d += 64;
tmp = buf[27] + buf[31];
s = buf[ 3]; d[0] = d[8] = s; d += 64;
s = buf[19] + tmp; d[0] = d[8] = s; d += 64;
s = buf[11] + buf[15]; d[0] = d[8] = s; d += 64;
s = buf[23] + tmp; d[0] = d[8] = s; d += 64;
tmp = buf[31];
s = buf[ 7]; d[0] = d[8] = s; d += 64;
s = buf[23] + tmp; d[0] = d[8] = s; d += 64;
s = buf[15]; d[0] = d[8] = s; d += 64;
s = tmp; d[0] = d[8] = s;
/* samples 16 to 1 (sample 16 used again) */
d = dest + 16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH);
s = buf[ 1]; d[0] = d[8] = s; d += 64;
tmp = buf[30] + buf[25];
s = buf[17] + tmp; d[0] = d[8] = s; d += 64;
s = buf[14] + buf[ 9]; d[0] = d[8] = s; d += 64;
s = buf[22] + tmp; d[0] = d[8] = s; d += 64;
s = buf[ 6]; d[0] = d[8] = s; d += 64;
tmp = buf[26] + buf[30];
s = buf[22] + tmp; d[0] = d[8] = s; d += 64;
s = buf[10] + buf[14]; d[0] = d[8] = s; d += 64;
s = buf[18] + tmp; d[0] = d[8] = s; d += 64;
s = buf[ 2]; d[0] = d[8] = s; d += 64;
tmp = buf[28] + buf[26];
s = buf[18] + tmp; d[0] = d[8] = s; d += 64;
s = buf[12] + buf[10]; d[0] = d[8] = s; d += 64;
s = buf[20] + tmp; d[0] = d[8] = s; d += 64;
s = buf[ 4]; d[0] = d[8] = s; d += 64;
tmp = buf[24] + buf[28];
s = buf[20] + tmp; d[0] = d[8] = s; d += 64;
s = buf[ 8] + buf[12]; d[0] = d[8] = s; d += 64;
s = buf[16] + tmp; d[0] = d[8] = s;
/* this is so rarely invoked that it's not worth making two versions of the output
* shuffle code (one for no shift, one for clip + variable shift) like in IMDCT
* here we just load, clip, shift, and store on the rare instances that es != 0
*/
if (es) {
d = dest + 64*16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH);
s = d[0]; CLIP_2N(s, 31 - es); d[0] = d[8] = (s << es);
d = dest + offset + (oddBlock ? VBUF_LENGTH : 0);
for (i = 16; i <= 31; i++) {
s = d[0]; CLIP_2N(s, 31 - es); d[0] = d[8] = (s << es); d += 64;
}
d = dest + 16 + ((offset - oddBlock) & 7) + (oddBlock ? 0 : VBUF_LENGTH);
for (i = 15; i >= 0; i--) {
s = d[0]; CLIP_2N(s, 31 - es); d[0] = d[8] = (s << es); d += 64;
}
}
}
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