ffmpeg / libavcodec / h264dspenc.c @ edecaff8
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/*


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* H.264/MPEG4 Part 10 (Base profile) encoder.

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*

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* DSP functions

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*

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* Copyright (c) 2006 Expertisecentrum Digitale Media, UHasselt

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*

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* FFmpeg 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 2.1 of the License, or (at your option) any later version.

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*

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* FFmpeg 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 FFmpeg; if not, write to the Free Software

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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 021101301 USA

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*/

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/**

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* @file h264dspenc.c

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* H.264 encoder related DSP utils

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*

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*/

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#include "dsputil.h" 
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extern const uint8_t ff_div6[52]; 
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extern const uint8_t ff_rem6[52]; 
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#define H264_DCT_PART1(X) \

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a = block[0][X]+block[3][X]; \ 
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c = block[0][X]block[3][X]; \ 
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b = block[1][X]+block[2][X]; \ 
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d = block[1][X]block[2][X]; \ 
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pieces[0][X] = a+b; \

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pieces[2][X] = ab; \

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pieces[1][X] = (c<<1)+d; \ 
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pieces[3][X] = c(d<<1); 
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#define H264_DCT_PART2(X) \

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a = pieces[X][0]+pieces[X][3]; \ 
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c = pieces[X][0]pieces[X][3]; \ 
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b = pieces[X][1]+pieces[X][2]; \ 
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d = pieces[X][1]pieces[X][2]; \ 
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block[0][X] = a+b; \

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block[2][X] = ab; \

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block[1][X] = (c<<1)+d; \ 
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block[3][X] = c(d<<1); 
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/**

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* Transform the provided matrix using the H.264 modified DCT.

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* @note

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* we'll always work with transposed input blocks, to avoid having to make a

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* distinction between C and mmx implementations.

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*

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* @param block transposed input block

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*/

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static void h264_dct_c(DCTELEM block[4][4]) 
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{ 
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DCTELEM pieces[4][4]; 
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DCTELEM a, b, c, d; 
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H264_DCT_PART1(0);

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H264_DCT_PART1(1);

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H264_DCT_PART1(2);

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H264_DCT_PART1(3);

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H264_DCT_PART2(0);

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H264_DCT_PART2(1);

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H264_DCT_PART2(2);

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H264_DCT_PART2(3);

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} 
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void ff_h264dspenc_init(DSPContext* c, AVCodecContext *avctx)

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{ 
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c>h264_dct = h264_dct_c; 
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} 
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