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/*
* H.261 common code
* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
* Copyright (c) 2004 Maarten Daniels
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* H.261 codec
*/
#include "h261.h"
#include "mpegvideo.h"
#define IS_FIL(a) ((a) & MB_TYPE_H261_FIL)
static void h261_loop_filter(uint8_t *src, ptrdiff_t stride)
{
int x, y;
int temp[64];
for (x = 0; x < 8; x++) {
temp[x] = 4 * src[x];
temp[x + 7 * 8] = 4 * src[x + 7 * stride];
}
for (y = 1; y < 7; y++) {
for (x = 0; x < 8; x++) {
ptrdiff_t xy = y * stride + x;
ptrdiff_t yz = y * 8 + x;
temp[yz] = src[xy - stride] + 2 * src[xy] + src[xy + stride];
}
}
for (y = 0; y < 8; y++) {
src[y * stride] = (temp[y * 8] + 2) >> 2;
src[y * stride + 7] = (temp[y * 8 + 7] + 2) >> 2;
for (x = 1; x < 7; x++) {
ptrdiff_t xy = y * stride + x;
ptrdiff_t yz = y * 8 + x;
src[xy] = (temp[yz - 1] + 2 * temp[yz] + temp[yz + 1] + 8) >> 4;
}
}
}
void ff_h261_loop_filter(MpegEncContext *s)
{
H261Context *const h = s->private_ctx;
const ptrdiff_t linesize = s->linesize;
const ptrdiff_t uvlinesize = s->uvlinesize;
uint8_t *dest_y = s->dest[0];
uint8_t *dest_cb = s->dest[1];
uint8_t *dest_cr = s->dest[2];
if (!(IS_FIL(h->mtype)))
return;
h261_loop_filter(dest_y, linesize);
h261_loop_filter(dest_y + 8, linesize);
h261_loop_filter(dest_y + 8 * linesize, linesize);
h261_loop_filter(dest_y + 8 * linesize + 8, linesize);
h261_loop_filter(dest_cb, uvlinesize);
h261_loop_filter(dest_cr, uvlinesize);
}
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