2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 #include "libavutil/mem.h"
28 static int noise(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args,
29 uint8_t **poutbuf, int *poutbuf_size,
30 const uint8_t *buf, int buf_size, int keyframe){
31 unsigned int *state= bsfc->priv_data;
32 int amount= args ? atoi(args) : (*state % 10001+1);
35 *poutbuf= av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
37 memcpy(*poutbuf, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
38 for(i=0; i<buf_size; i++){
39 (*state) += (*poutbuf)[i] + 1;
40 if(*state % amount == 0)
41 (*poutbuf)[i] = *state;
46 AVBitStreamFilter ff_noise_bsf={