yading@10: /*
yading@10:  * H261 common code
yading@10:  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
yading@10:  * Copyright (c) 2004 Maarten Daniels
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * h261codec.
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "h261.h"
yading@10: 
yading@10: #define IS_FIL(a)    ((a) & MB_TYPE_H261_FIL)
yading@10: 
yading@10: uint8_t ff_h261_rl_table_store[2][2 * MAX_RUN + MAX_LEVEL + 3];
yading@10: 
yading@10: static void h261_loop_filter(uint8_t *src, int stride)
yading@10: {
yading@10:     int x, y, xy, yz;
yading@10:     int temp[64];
yading@10: 
yading@10:     for (x = 0; x < 8; x++) {
yading@10:         temp[x]         = 4 * src[x];
yading@10:         temp[x + 7 * 8] = 4 * src[x + 7 * stride];
yading@10:     }
yading@10:     for (y = 1; y < 7; y++) {
yading@10:         for (x = 0; x < 8; x++) {
yading@10:             xy       = y * stride + x;
yading@10:             yz       = y * 8      + x;
yading@10:             temp[yz] = src[xy - stride] + 2 * src[xy] + src[xy + stride];
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     for (y = 0; y < 8; y++) {
yading@10:         src[y * stride]     = (temp[y * 8]     + 2) >> 2;
yading@10:         src[y * stride + 7] = (temp[y * 8 + 7] + 2) >> 2;
yading@10:         for (x = 1; x < 7; x++) {
yading@10:             xy      = y * stride + x;
yading@10:             yz      = y * 8      + x;
yading@10:             src[xy] = (temp[yz - 1] + 2 * temp[yz] + temp[yz + 1] + 8) >> 4;
yading@10:         }
yading@10:     }
yading@10: }
yading@10: 
yading@10: void ff_h261_loop_filter(MpegEncContext *s)
yading@10: {
yading@10:     H261Context *h       = (H261Context *)s;
yading@10:     const int linesize   = s->linesize;
yading@10:     const int uvlinesize = s->uvlinesize;
yading@10:     uint8_t *dest_y      = s->dest[0];
yading@10:     uint8_t *dest_cb     = s->dest[1];
yading@10:     uint8_t *dest_cr     = s->dest[2];
yading@10: 
yading@10:     if (!(IS_FIL(h->mtype)))
yading@10:         return;
yading@10: 
yading@10:     h261_loop_filter(dest_y,                    linesize);
yading@10:     h261_loop_filter(dest_y + 8,                linesize);
yading@10:     h261_loop_filter(dest_y + 8 * linesize,     linesize);
yading@10:     h261_loop_filter(dest_y + 8 * linesize + 8, linesize);
yading@10:     h261_loop_filter(dest_cb, uvlinesize);
yading@10:     h261_loop_filter(dest_cr, uvlinesize);
yading@10: }
yading@10: 
yading@10: av_cold void ff_h261_common_init(void)
yading@10: {
yading@10:     static int done = 0;
yading@10: 
yading@10:     if (done)
yading@10:         return;
yading@10: 
yading@10:     ff_init_rl(&ff_h261_rl_tcoeff, ff_h261_rl_table_store);
yading@10:     done = 1;
yading@10: }