rockbox/apps/plugins/mpegplayer/idct_arm_c.c
Robert Kukla fd3fe45bc1 FS#7487 - mpegplayer - video start time seek with resume
by John S. Gwynne & Brian J. Morey
This should stop the patch from breaking again and give them opportunity to improve it further.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15052 a1c6a512-1295-4272-9138-f99709370657
2007-10-09 20:42:20 +00:00

529 lines
22 KiB
C

/*
* idct.c
* Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
* Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
*
* This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
* See http://libmpeg2.sourceforge.net/ for updates.
*
* mpeg2dec is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* mpeg2dec is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "plugin.h"
#include "mpeg2dec_config.h"
#include "mpeg2.h"
#include "attributes.h"
#include "mpeg2_internal.h"
/* 101100011001 */
#define W1 2841 /* 2048 * sqrt (2) * cos (1 * pi / 16) */
/* 101001110100 */
#define W2 2676 /* 2048 * sqrt (2) * cos (2 * pi / 16) */
/* 100101101000 */
#define W3 2408 /* 2048 * sqrt (2) * cos (3 * pi / 16) */
/* 011001001001 */
#define W5 1609 /* 2048 * sqrt (2) * cos (5 * pi / 16) */
/* 010001010100 */
#define W6 1108 /* 2048 * sqrt (2) * cos (6 * pi / 16) */
/* 001000110101 */
#define W7 565 /* 2048 * sqrt (2) * cos (7 * pi / 16) */
/* idct main entry point */
void (* mpeg2_idct_copy) (int16_t * block, uint8_t * dest, int stride);
void (* mpeg2_idct_add) (int last, int16_t * block,
uint8_t * dest, int stride);
/*
* In legal streams, the IDCT output should be between -384 and +384.
* In corrupted streams, it is possible to force the IDCT output to go
* to +-3826 - this is the worst case for a column IDCT where the
* column inputs are 16-bit values.
*/
#if 0
#define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
do { \
t0 = W0 * d0 + W1 * d1; \
t1 = W0 * d1 - W1 * d0; \
} while (0)
#else
#define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
do { \
int tmp = W0 * (d0 + d1); \
t0 = tmp + (W1 - W0) * d1; \
t1 = tmp - (W1 + W0) * d0; \
} while (0)
#endif
/* Custom calling convention:
* r0 contains block pointer and is non-volatile
* all non-volatile c context saved and restored on its behalf
*/
static void idct (int16_t * block) __attribute__((naked,used));
static void idct (int16_t * block)
{
asm volatile (
"add r12, r0, #128 \n"
"1: \n"
"ldrsh r1, [r0, #0] \n" /* d0 */
"ldrsh r2, [r0, #2] \n" /* d1 */
"ldrsh r3, [r0, #4] \n" /* d2 */
"ldrsh r4, [r0, #6] \n" /* d3 */
"ldrsh r5, [r0, #8] \n" /* d0 */
"ldrsh r6, [r0, #10] \n" /* d1 */
"ldrsh r7, [r0, #12] \n" /* d2 */
"ldrsh r8, [r0, #14] \n" /* d3 */
"orrs r9, r2, r3 \n"
"orreqs r9, r4, r5 \n"
"orreqs r9, r6, r7 \n"
"cmpeq r8, #0 \n"
"bne 2f \n"
"mov r1, r1, asl #15 \n"
"bic r1, r1, #0x8000 \n"
"orr r1, r1, r1, lsr #16 \n"
"str r1, [r0], #4 \n"
"str r1, [r0], #4 \n"
"str r1, [r0], #4 \n"
"str r1, [r0], #4 \n"
"cmp r0, r12 \n"
"blo 1b \n"
"b 3f \n"
"2: \n"
"mov r1, r1, asl #11 \n" /* r1 = d0 = (block[0] << 11) + 2048 */
"add r1, r1, #2048 \n"
"add r1, r1, r3, asl #11 \n" /* r1 = t0 = d0 + (block[2] << 11) */
"sub r3, r1, r3, asl #12 \n" /* r3 = t1 = d0 - (block[2] << 11) */
"add r9, r2, r4 \n" /* r9 = tmp = (d1+d3)*(1108/4) */
"add r10, r9, r9, asl #2 \n"
"add r10, r10, r9, asl #4 \n"
"add r9, r10, r9, asl #8 \n"
"add r10, r2, r2, asl #4 \n" /* r2 = t2 = tmp + (d1*(1568/32)*8) */
"add r2, r10, r2, asl #5 \n"
"add r2, r9, r2, asl #3 \n"
"add r10, r4, r4, asl #2 \n" /* r4 = t3 = tmp - (d3*(3784/8)*2) */
"rsb r10, r10, r4, asl #6 \n"
"add r4, r4, r10, asl #3 \n"
"sub r4, r9, r4, asl #1 \n"
/* t2 & t3 are 1/4 final value here */
"add r1, r1, r2, asl #2 \n" /* r1 = a0 = t0 + t2 */
"sub r2, r1, r2, asl #3 \n" /* r2 = a3 = t0 - t2 */
"add r3, r3, r4, asl #2 \n" /* r3 = a1 = t1 + t3 */
"sub r4, r3, r4, asl #3 \n" /* r4 = a2 = t1 - t3 */
"add r9, r8, r5 \n" /* r9 = tmp = 565*(d3 + d0) */
"add r10, r9, r9, asl #4 \n"
"add r10, r10, r10, asl #5 \n"
"add r9, r10, r9, asl #2 \n"
"add r10, r5, r5, asl #4 \n" /* r5 = t0 = tmp + (((2276/4)*d0)*4) */
"add r10, r10, r10, asl #5 \n"
"add r5, r10, r5, asl #3 \n"
"add r5, r9, r5, asl #2 \n"
"add r10, r8, r8, asl #2 \n" /* r8 = t1 = tmp - (((3406/2)*d3)*2) */
"add r10, r10, r10, asl #4 \n"
"add r10, r10, r8, asl #7 \n"
"rsb r8, r8, r10, asl #3 \n"
"sub r8, r9, r8, asl #1 \n"
"add r9, r6, r7 \n" /* r9 = tmp = (2408/8)*(d1 + d2) */
"add r10, r9, r9, asl #3 \n"
"add r10, r10, r10, asl #5 \n"
"add r9, r10, r9, asl #2 \n"
"add r10, r7, r7, asl #3 \n" /* r7 = t2 = (tmp*8) - 799*d2 */
"add r10, r10, r7, asl #4 \n"
"rsb r7, r7, r10, asl #5 \n"
"rsb r7, r7, r9, asl #3 \n"
"sub r10, r6, r6, asl #4 \n" /* r6 = t3 = (tmp*8) - 4017*d1 */
"sub r10, r10, r6, asl #6 \n"
"add r10, r10, r6, asl #12 \n"
"add r6, r10, r6 \n"
"rsb r6, r6, r9, asl #3 \n"
/* t0 = r5, t1 = r8, t2 = r7, t3 = r6*/
"add r9, r5, r7 \n" /* r9 = b0 = t0 + t2 */
"add r10, r8, r6 \n" /* r10 = b3 = t1 + t3 */
"sub r5, r5, r7 \n" /* t0 -= t2 */
"sub r8, r8, r6 \n" /* t1 -= t3 */
"add r6, r5, r8 \n" /* r6 = t0 + t1 */
"sub r7, r5, r8 \n" /* r7 = t0 - t1 */
"add r11, r6, r6, asr #2 \n" /* r6 = b1 = r6*(181/128) */
"add r11, r11, r11, asr #5 \n"
"add r6, r11, r6, asr #3 \n"
"add r11, r7, r7, asr #2 \n" /* r7 = b2 = r7*(181/128) */
"add r11, r11, r11, asr #5 \n"
"add r7, r11, r7, asr #3 \n"
/* r1 = a0, r3 = a1, r4 = a2, r2 = a3 */
/* r9 = b0, r6 = b1*2, r7 = b2*2, r10 = b3 */
"add r5, r1, r9 \n" /* block[0] = (a0 + b0) >> 12 */
"mov r5, r5, asr #12 \n"
"strh r5, [r0], #2 \n"
"add r8, r3, r6, asr #1 \n" /* block[1] = (a1 + b1) >> 12 */
"mov r8, r8, asr #12 \n"
"strh r8, [r0], #2 \n"
"add r5, r4, r7, asr #1 \n" /* block[2] = (a2 + b2) >> 12 */
"mov r5, r5, asr #12 \n"
"strh r5, [r0], #2 \n"
"add r8, r2, r10 \n" /* block[3] = (a3 + b3) >> 12 */
"mov r8, r8, asr #12 \n"
"strh r8, [r0], #2 \n"
"sub r5, r2, r10 \n" /* block[4] = (a3 - b3) >> 12 */
"mov r5, r5, asr #12 \n"
"strh r5, [r0], #2 \n"
"sub r8, r4, r7, asr #1 \n" /* block[5] = (a2 - b2) >> 12 */
"mov r8, r8, asr #12 \n"
"strh r8, [r0], #2 \n"
"sub r5, r3, r6, asr #1 \n" /* block[6] = (a1 - b1) >> 12 */
"mov r5, r5, asr #12 \n"
"strh r5, [r0], #2 \n"
"sub r8, r1, r9 \n" /* block[7] = (a0 - b0) >> 12 */
"mov r8, r8, asr #12 \n"
"strh r8, [r0], #2 \n"
"cmp r0, r12 \n"
"blo 1b \n"
"3: \n"
"sub r0, r0, #128 \n"
"add r12, r0, #16 \n"
"4: \n"
"ldrsh r1, [r0, #0*8] \n" /* d0 */
"ldrsh r2, [r0, #2*8] \n" /* d1 */
"ldrsh r3, [r0, #4*8] \n" /* d2 */
"ldrsh r4, [r0, #6*8] \n" /* d3 */
"ldrsh r5, [r0, #8*8] \n" /* d0 */
"ldrsh r6, [r0, #10*8] \n" /* d1 */
"ldrsh r7, [r0, #12*8] \n" /* d2 */
"ldrsh r8, [r0, #14*8] \n" /* d3 */
"mov r1, r1, asl #11 \n" /* r1 = d0 = (block[0] << 11) + 2048 */
"add r1, r1, #65536 \n"
"add r1, r1, r3, asl #11 \n" /* r1 = t0 = d0 + d2:(block[2] << 11) */
"sub r3, r1, r3, asl #12 \n" /* r3 = t1 = d0 - d2:(block[2] << 11) */
"add r9, r2, r4 \n" /* r9 = tmp = (d1+d3)*(1108/4) */
"add r10, r9, r9, asl #2 \n"
"add r10, r10, r9, asl #4 \n"
"add r9, r10, r9, asl #8 \n"
"add r11, r2, r2, asl #4 \n" /* r2 = t2 = tmp + (d1*(1568/32)*8) */
"add r2, r11, r2, asl #5 \n"
"add r2, r9, r2, asl #3 \n"
"add r10, r4, r4, asl #2 \n" /* r4 = t3 = tmp - (d3*(3784/8)*2) */
"rsb r10, r10, r4, asl #6 \n"
"add r4, r4, r10, asl #3 \n"
"sub r4, r9, r4, asl #1 \n"
/* t2 & t3 are 1/4 final value here */
"add r1, r1, r2, asl #2 \n" /* r1 = a0 = t0 + t2 */
"sub r2, r1, r2, asl #3 \n" /* r2 = a3 = t0 - t2 */
"add r3, r3, r4, asl #2 \n" /* r3 = a1 = t1 + t3 */
"sub r4, r3, r4, asl #3 \n" /* r4 = a2 = t1 - t3 */
"add r9, r8, r5 \n" /* r9 = tmp = 565*(d3 + d0) */
"add r10, r9, r9, asl #4 \n"
"add r10, r10, r10, asl #5 \n"
"add r9, r10, r9, asl #2 \n"
"add r10, r5, r5, asl #4 \n" /* r5 = t0 = tmp + (((2276/4)*d0)*4) */
"add r10, r10, r10, asl #5 \n"
"add r5, r10, r5, asl #3 \n"
"add r5, r9, r5, asl #2 \n"
"add r10, r8, r8, asl #2 \n" /* r8 = t1 = tmp - (((3406/2)*d3)*2) */
"add r10, r10, r10, asl #4 \n"
"add r10, r10, r8, asl #7 \n"
"rsb r8, r8, r10, asl #3 \n"
"sub r8, r9, r8, asl #1 \n"
"add r9, r6, r7 \n" /* r9 = tmp = (2408/8)*(d1 + d2) */
"add r10, r9, r9, asl #3 \n"
"add r10, r10, r10, asl #5 \n"
"add r9, r10, r9, asl #2 \n"
"add r10, r7, r7, asl #3 \n" /* r7 = t2 = (tmp*8) - 799*d2 */
"add r10, r10, r7, asl #4 \n"
"rsb r7, r7, r10, asl #5 \n"
"rsb r7, r7, r9, asl #3 \n"
"sub r10, r6, r6, asl #4 \n" /* r6 = t3 = (tmp*8) - 4017*d1 */
"sub r10, r10, r6, asl #6 \n"
"add r10, r10, r6, asl #12 \n"
"add r6, r10, r6 \n"
"rsb r6, r6, r9, asl #3 \n"
/* t0=r5, t1=r8, t2=r7, t3=r6*/
"add r9, r5, r7 \n" /* r9 = b0 = t0 + t2 */
"add r10, r8, r6 \n" /* r10 = b3 = t1 + t3 */
"sub r5, r5, r7 \n" /* t0 -= t2 */
"sub r8, r8, r6 \n" /* t1 -= t3 */
"add r6, r5, r8 \n" /* r6 = t0 + t1 */
"sub r7, r5, r8 \n" /* r7 = t0 - t1 */
"add r11, r6, r6, asr #2 \n" /* r6 = b1 = r5*(181/128) */
"add r11, r11, r11, asr #5 \n"
"add r6, r11, r6, asr #3 \n"
"add r11, r7, r7, asr #2 \n" /* r7 = b2 = r6*(181/128) */
"add r11, r11, r11, asr #5 \n"
"add r7, r11, r7, asr #3 \n"
/* r1 = a0, r3 = a1, r4 = a2, r2 = a3 */
/* r9 = b0, r6 = b1*2, r7 = b2*2, r10 = b3 */
"add r5, r1, r9 \n" /* block[0] = (a0 + b0) >> 17 */
"mov r5, r5, asr #17 \n"
"strh r5, [r0, #0*8] \n"
"add r8, r3, r6, asr #1 \n" /* block[1] = (a1 + b1) >> 17 */
"mov r8, r8, asr #17 \n"
"strh r8, [r0, #2*8] \n"
"add r5, r4, r7, asr #1 \n" /* block[2] = (a2 + b2) >> 17 */
"mov r5, r5, asr #17 \n"
"strh r5, [r0, #4*8] \n"
"add r8, r2, r10 \n" /* block[3] = (a3 + b3) >> 17 */
"mov r8, r8, asr #17 \n"
"strh r8, [r0, #6*8] \n"
"sub r5, r2, r10 \n" /* block[4] = (a3 - b3) >> 17 */
"mov r5, r5, asr #17 \n"
"strh r5, [r0, #8*8] \n"
"sub r8, r4, r7, asr #1 \n" /* block[5] = (a2 - b2) >> 17 */
"mov r8, r8, asr #17 \n"
"strh r8, [r0, #10*8] \n"
"sub r5, r3, r6, asr #1 \n" /* block[6] = (a1 - b1) >> 17 */
"mov r5, r5, asr #17 \n"
"strh r5, [r0, #12*8] \n"
"sub r8, r1, r9 \n" /* block[7] = (a0 - b0) >> 17 */
"mov r8, r8, asr #17 \n"
"strh r8, [r0, #14*8] \n"
"add r0, r0, #2 \n"
"cmp r0, r12 \n"
"blo 4b \n"
"sub r0, r0, #16 \n"
"bx lr \n"
);
(void)block;
}
static void mpeg2_idct_copy_c (int16_t * block, uint8_t * dest,
const int stride) __attribute__((naked));
static void mpeg2_idct_copy_c (int16_t * block, uint8_t * dest,
const int stride)
{
asm volatile(
"stmfd sp!, { r1-r2, \
r4-r12, lr } \n"
"bl idct \n"
"ldmfd sp!, { r1-r2 } \n"
"mov r11, #0 \n"
"add r12, r0, #128 \n"
"1: \n"
"ldrsh r3, [r0, #0] \n"
"ldrsh r4, [r0, #2] \n"
"ldrsh r5, [r0, #4] \n"
"ldrsh r6, [r0, #6] \n"
"ldrsh r7, [r0, #8] \n"
"ldrsh r8, [r0, #10] \n"
"ldrsh r9, [r0, #12] \n"
"ldrsh r10, [r0, #14] \n"
"cmp r3, #255 \n"
"mvnhi r3, r3, asr #31 \n"
"strb r3, [r1, #0] \n"
"str r11, [r0], #4 \n"
"cmp r4, #255 \n"
"mvnhi r4, r4, asr #31 \n"
"strb r4, [r1, #1] \n"
"cmp r5, #255 \n"
"mvnhi r5, r5, asr #31 \n"
"strb r5, [r1, #2] \n"
"str r11, [r0], #4 \n"
"cmp r6, #255 \n"
"mvnhi r6, r6, asr #31 \n"
"strb r6, [r1, #3] \n"
"cmp r7, #255 \n"
"mvnhi r7, r7, asr #31 \n"
"strb r7, [r1, #4] \n"
"str r11, [r0], #4 \n"
"cmp r8, #255 \n"
"mvnhi r8, r8, asr #31 \n"
"strb r8, [r1, #5] \n"
"cmp r9, #255 \n"
"mvnhi r9, r9, asr #31 \n"
"strb r9, [r1, #6] \n"
"str r11, [r0], #4 \n"
"cmp r10, #255 \n"
"mvnhi r10, r10, asr #31 \n"
"strb r10, [r1, #7] \n"
"add r1, r1, r2 \n"
"cmp r0, r12 \n"
"blo 1b \n"
"ldmfd sp!, { r4-r12, pc } \n"
);
(void)block; (void)dest; (void)stride;
}
static void mpeg2_idct_add_c (int last, int16_t * block,
uint8_t * dest, const int stride) __attribute__((naked));
static void mpeg2_idct_add_c (int last, int16_t * block,
uint8_t * dest, const int stride)
{
asm volatile (
"cmp r0, #129 \n"
"mov r0, r1 \n"
"ldreqsh r1, [r0, #0] \n"
"bne 1f \n"
"and r1, r1, #0x70 \n"
"cmp r1, #0x40 \n"
"bne 3f \n"
"1: \n"
"stmfd sp!, { r2-r12, lr } \n"
"bl idct \n"
"ldmfd sp!, { r1-r2 } \n"
"mov r11, #0 \n"
"add r12, r0, #128 \n"
"2: \n"
"ldrb r3, [r1, #0] \n"
"ldrb r4, [r1, #1] \n"
"ldrb r5, [r1, #2] \n"
"ldrb r6, [r1, #3] \n"
"ldrsh r7, [r0, #0] \n"
"ldrsh r8, [r0, #2] \n"
"ldrsh r9, [r0, #4] \n"
"ldrsh r10, [r0, #6] \n"
"add r7, r7, r3 \n"
"ldrb r3, [r1, #4] \n"
"cmp r7, #255 \n"
"mvnhi r7, r7, asr #31 \n"
"strb r7, [r1, #0] \n"
"ldrsh r7, [r0, #8] \n"
"add r8, r8, r4 \n"
"ldrb r4, [r1, #5] \n"
"cmp r8, #255 \n"
"mvnhi r8, r8, asr #31 \n"
"strb r8, [r1, #1] \n"
"ldrsh r8, [r0, #10] \n"
"add r9, r9, r5 \n"
"ldrb r5, [r1, #6] \n"
"cmp r9, #255 \n"
"mvnhi r9, r9, asr #31 \n"
"strb r9, [r1, #2] \n"
"ldrsh r9, [r0, #12] \n"
"add r10, r10, r6 \n"
"ldrb r6, [r1, #7] \n"
"cmp r10, #255 \n"
"mvnhi r10, r10, asr #31 \n"
"strb r10, [r1, #3] \n"
"ldrsh r10, [r0, #14] \n"
"str r11, [r0], #4 \n"
"add r7, r7, r3 \n"
"cmp r7, #255 \n"
"mvnhi r7, r7, asr #31 \n"
"strb r7, [r1, #4] \n"
"str r11, [r0], #4 \n"
"add r8, r8, r4 \n"
"cmp r8, #255 \n"
"mvnhi r8, r8, asr #31 \n"
"strb r8, [r1, #5] \n"
"str r11, [r0], #4 \n"
"add r9, r9, r5 \n"
"cmp r9, #255 \n"
"mvnhi r9, r9, asr #31 \n"
"strb r9, [r1, #6] \n"
"add r10, r10, r6 \n"
"cmp r10, #255 \n"
"mvnhi r10, r10, asr #31 \n"
"strb r10, [r1, #7] \n"
"str r11, [r0], #4 \n"
"add r1, r1, r2 \n"
"cmp r0, r12 \n"
"blo 2b \n"
"ldmfd sp!, { r4-r12, pc } \n"
"3: \n"
"stmfd sp!, { r4-r11 } \n"
"ldrsh r1, [r0, #0] \n" /* r1 = block[0] */
"mov r11, #0 \n"
"strh r11, [r0, #0] \n" /* block[0] = 0 */
"strh r11, [r0, #126] \n" /* block[63] = 0 */
"add r1, r1, #64 \n" /* r1 = DC << 7 */
"add r0, r2, r3, asl #3 \n"
"4: \n"
"ldrb r4, [r2, #0] \n"
"ldrb r5, [r2, #1] \n"
"ldrb r6, [r2, #2] \n"
"ldrb r7, [r2, #3] \n"
"ldrb r8, [r2, #4] \n"
"ldrb r9, [r2, #5] \n"
"ldrb r10, [r2, #6] \n"
"ldrb r11, [r2, #7] \n"
"add r4, r4, r1, asr #7 \n"
"cmp r4, #255 \n"
"mvnhi r4, r4, asr #31 \n"
"strb r4, [r2, #0] \n"
"add r5, r5, r1, asr #7 \n"
"cmp r5, #255 \n"
"mvnhi r5, r5, asr #31 \n"
"strb r5, [r2, #1] \n"
"add r6, r6, r1, asr #7 \n"
"cmp r6, #255 \n"
"mvnhi r6, r6, asr #31 \n"
"strb r6, [r2, #2] \n"
"add r7, r7, r1, asr #7 \n"
"cmp r7, #255 \n"
"mvnhi r7, r7, asr #31 \n"
"strb r7, [r2, #3] \n"
"add r8, r8, r1, asr #7 \n"
"cmp r8, #255 \n"
"mvnhi r8, r8, asr #31 \n"
"strb r8, [r2, #4] \n"
"add r9, r9, r1, asr #7 \n"
"cmp r9, #255 \n"
"mvnhi r9, r9, asr #31 \n"
"strb r9, [r2, #5] \n"
"add r10, r10, r1, asr #7 \n"
"cmp r10, #255 \n"
"mvnhi r10, r10, asr #31 \n"
"strb r10, [r2, #6] \n"
"add r11, r11, r1, asr #7 \n"
"cmp r11, #255 \n"
"mvnhi r11, r11, asr #31 \n"
"strb r11, [r2, #7] \n"
"add r2, r2, r3 \n"
"cmp r2, r0 \n"
"blo 4b \n"
"ldmfd sp!, { r4-r11 } \n"
"bx lr \n"
);
(void)last; (void)block; (void)dest; (void)stride;
}
void mpeg2_idct_init (void)
{
extern uint8_t default_mpeg2_scan_norm[64];
extern uint8_t default_mpeg2_scan_alt[64];
extern uint8_t mpeg2_scan_norm[64];
extern uint8_t mpeg2_scan_alt[64];
int i, j;
mpeg2_idct_copy = mpeg2_idct_copy_c;
mpeg2_idct_add = mpeg2_idct_add_c;
for (i = 0; i < 64; i++)
{
j = default_mpeg2_scan_norm[i];
mpeg2_scan_norm[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
j = default_mpeg2_scan_alt[i];
mpeg2_scan_alt[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
}
}