ffmpeg/libavcodec/rv34dsp.c

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/*
* RV30/40 decoder common dsp functions
* Copyright (c) 2007 Mike Melanson, Konstantin Shishkov
* Copyright (c) 2011 Janne Grunau
*
* This file is part of Libav.
*
* Libav 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 2.1 of the License, or (at your option) any later version.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* RV30/40 decoder common dsp functions
*/
#include "dsputil.h"
#include "rv34dsp.h"
/**
* @name RV30/40 inverse transform functions
* @{
*/
static av_always_inline void rv34_row_transform(int temp[16], DCTELEM *block)
{
int i;
for(i = 0; i < 4; i++){
const int z0 = 13*(block[i+8*0] + block[i+8*2]);
const int z1 = 13*(block[i+8*0] - block[i+8*2]);
const int z2 = 7* block[i+8*1] - 17*block[i+8*3];
const int z3 = 17* block[i+8*1] + 7*block[i+8*3];
temp[4*i+0] = z0 + z3;
temp[4*i+1] = z1 + z2;
temp[4*i+2] = z1 - z2;
temp[4*i+3] = z0 - z3;
}
}
/**
* Real Video 3.0/4.0 inverse transform
* Code is almost the same as in SVQ3, only scaling is different.
*/
static void rv34_inv_transform_c(DCTELEM *block){
int temp[16];
int i;
rv34_row_transform(temp, block);
for(i = 0; i < 4; i++){
const int z0 = 13*(temp[4*0+i] + temp[4*2+i]) + 0x200;
const int z1 = 13*(temp[4*0+i] - temp[4*2+i]) + 0x200;
const int z2 = 7* temp[4*1+i] - 17*temp[4*3+i];
const int z3 = 17* temp[4*1+i] + 7*temp[4*3+i];
block[i*8+0] = (z0 + z3) >> 10;
block[i*8+1] = (z1 + z2) >> 10;
block[i*8+2] = (z1 - z2) >> 10;
block[i*8+3] = (z0 - z3) >> 10;
}
}
/**
* RealVideo 3.0/4.0 inverse transform for DC block
*
* Code is almost the same as rv34_inv_transform()
* but final coefficients are multiplied by 1.5 and have no rounding.
*/
static void rv34_inv_transform_noround_c(DCTELEM *block){
int temp[16];
int i;
rv34_row_transform(temp, block);
for(i = 0; i < 4; i++){
const int z0 = 13*(temp[4*0+i] + temp[4*2+i]);
const int z1 = 13*(temp[4*0+i] - temp[4*2+i]);
const int z2 = 7* temp[4*1+i] - 17*temp[4*3+i];
const int z3 = 17* temp[4*1+i] + 7*temp[4*3+i];
block[i*8+0] = ((z0 + z3) * 3) >> 11;
block[i*8+1] = ((z1 + z2) * 3) >> 11;
block[i*8+2] = ((z1 - z2) * 3) >> 11;
block[i*8+3] = ((z0 - z3) * 3) >> 11;
}
}
/** @} */ // transform
av_cold void ff_rv34dsp_init(RV34DSPContext *c, DSPContext* dsp) {
c->rv34_inv_transform_tab[0] = rv34_inv_transform_c;
c->rv34_inv_transform_tab[1] = rv34_inv_transform_noround_c;
}