mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
71 lines
2.7 KiB
71 lines
2.7 KiB
20 years ago
|
/*
|
||
|
|
* H.264 IDCT
|
||
|
|
* Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
|
||
|
|
*
|
||
|
|
* This library is free software; you can redistribute it and/or
|
||
|
|
* modify it under the terms of the GNU Lesser General Public
|
||
|
|
* License as published by the Free Software Foundation; either
|
||
|
|
* version 2 of the License, or (at your option) any later version.
|
||
|
|
*
|
||
|
|
* This library 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
|
||
|
|
* Lesser General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU Lesser General Public
|
||
|
|
* License along with this library; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
/**
|
||
|
|
* @file h264-idct.c
|
||
|
|
* H.264 IDCT.
|
||
|
|
* @author Michael Niedermayer <michaelni@gmx.at>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "dsputil.h"
|
||
|
|
|
||
|
|
static always_inline void idct_internal(uint8_t *dst, DCTELEM *block, int stride, int block_stride, int shift, int add){
|
||
|
|
int i;
|
||
|
|
uint8_t *cm = cropTbl + MAX_NEG_CROP;
|
||
|
|
|
||
|
|
block[0] += 1<<(shift-1);
|
||
|
|
|
||
|
|
for(i=0; i<4; i++){
|
||
|
|
const int z0= block[0 + block_stride*i] + block[2 + block_stride*i];
|
||
|
|
const int z1= block[0 + block_stride*i] - block[2 + block_stride*i];
|
||
|
|
const int z2= (block[1 + block_stride*i]>>1) - block[3 + block_stride*i];
|
||
|
|
const int z3= block[1 + block_stride*i] + (block[3 + block_stride*i]>>1);
|
||
|
|
|
||
|
|
block[0 + block_stride*i]= z0 + z3;
|
||
|
|
block[1 + block_stride*i]= z1 + z2;
|
||
|
|
block[2 + block_stride*i]= z1 - z2;
|
||
|
|
block[3 + block_stride*i]= z0 - z3;
|
||
|
|
}
|
||
|
|
|
||
|
|
for(i=0; i<4; i++){
|
||
|
|
const int z0= block[i + block_stride*0] + block[i + block_stride*2];
|
||
|
|
const int z1= block[i + block_stride*0] - block[i + block_stride*2];
|
||
|
|
const int z2= (block[i + block_stride*1]>>1) - block[i + block_stride*3];
|
||
|
|
const int z3= block[i + block_stride*1] + (block[i + block_stride*3]>>1);
|
||
|
|
|
||
|
|
dst[i + 0*stride]= cm[ add*dst[i + 0*stride] + ((z0 + z3) >> shift) ];
|
||
|
|
dst[i + 1*stride]= cm[ add*dst[i + 1*stride] + ((z1 + z2) >> shift) ];
|
||
|
|
dst[i + 2*stride]= cm[ add*dst[i + 2*stride] + ((z1 - z2) >> shift) ];
|
||
|
|
dst[i + 3*stride]= cm[ add*dst[i + 3*stride] + ((z0 - z3) >> shift) ];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void ff_h264_idct_add_c(uint8_t *dst, DCTELEM *block, int stride){
|
||
|
|
idct_internal(dst, block, stride, 4, 6, 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
void ff_h264_lowres_idct_add_c(uint8_t *dst, int stride, DCTELEM *block){
|
||
|
|
idct_internal(dst, block, stride, 8, 3, 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
void ff_h264_lowres_idct_put_c(uint8_t *dst, int stride, DCTELEM *block){
|
||
|
|
idct_internal(dst, block, stride, 8, 3, 0);
|
||
|
|
}
|