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70 lines
2.7 KiB
70 lines
2.7 KiB
/* |
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* H.264 IDCT |
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* Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> |
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* |
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* This library is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2 of the License, or (at your option) any later version. |
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* |
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* This library is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with this library; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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* |
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*/ |
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/** |
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* @file h264-idct.c |
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* H.264 IDCT. |
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* @author Michael Niedermayer <michaelni@gmx.at> |
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*/ |
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#include "dsputil.h" |
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static always_inline void idct_internal(uint8_t *dst, DCTELEM *block, int stride, int block_stride, int shift, int add){ |
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int i; |
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uint8_t *cm = cropTbl + MAX_NEG_CROP; |
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block[0] += 1<<(shift-1); |
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for(i=0; i<4; i++){ |
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const int z0= block[0 + block_stride*i] + block[2 + block_stride*i]; |
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const int z1= block[0 + block_stride*i] - block[2 + block_stride*i]; |
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const int z2= (block[1 + block_stride*i]>>1) - block[3 + block_stride*i]; |
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const int z3= block[1 + block_stride*i] + (block[3 + block_stride*i]>>1); |
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block[0 + block_stride*i]= z0 + z3; |
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block[1 + block_stride*i]= z1 + z2; |
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block[2 + block_stride*i]= z1 - z2; |
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block[3 + block_stride*i]= z0 - z3; |
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} |
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for(i=0; i<4; i++){ |
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const int z0= block[i + block_stride*0] + block[i + block_stride*2]; |
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const int z1= block[i + block_stride*0] - block[i + block_stride*2]; |
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const int z2= (block[i + block_stride*1]>>1) - block[i + block_stride*3]; |
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const int z3= block[i + block_stride*1] + (block[i + block_stride*3]>>1); |
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dst[i + 0*stride]= cm[ add*dst[i + 0*stride] + ((z0 + z3) >> shift) ]; |
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dst[i + 1*stride]= cm[ add*dst[i + 1*stride] + ((z1 + z2) >> shift) ]; |
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dst[i + 2*stride]= cm[ add*dst[i + 2*stride] + ((z1 - z2) >> shift) ]; |
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dst[i + 3*stride]= cm[ add*dst[i + 3*stride] + ((z0 - z3) >> shift) ]; |
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} |
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} |
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void ff_h264_idct_add_c(uint8_t *dst, DCTELEM *block, int stride){ |
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idct_internal(dst, block, stride, 4, 6, 1); |
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} |
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void ff_h264_lowres_idct_add_c(uint8_t *dst, int stride, DCTELEM *block){ |
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idct_internal(dst, block, stride, 8, 3, 1); |
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} |
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void ff_h264_lowres_idct_put_c(uint8_t *dst, int stride, DCTELEM *block){ |
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idct_internal(dst, block, stride, 8, 3, 0); |
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}
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