From 0fa8158d3e70eccda141df1d18cff648530c0cf5 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 27 Sep 2004 19:47:17 +0000 Subject: move h264 idct to its own file and call via function pointer in DspContext allow h264 idct to be used for lowres=1 Originally committed as revision 3524 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/h264idct.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 libavcodec/h264idct.c (limited to 'libavcodec/h264idct.c') diff --git a/libavcodec/h264idct.c b/libavcodec/h264idct.c new file mode 100644 index 0000000000..551197d37e --- /dev/null +++ b/libavcodec/h264idct.c @@ -0,0 +1,70 @@ +/* + * H.264 IDCT + * Copyright (c) 2004 Michael Niedermayer + * + * 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 + */ + +#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); +} -- cgit v1.2.3