1/* 2 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> 3 * 4 * This file is part of FFmpeg. 5 * 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. 10 * 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. 15 * 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 19 */ 20 21#include "avcodec.h" 22 23 24static int noise(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args, 25 uint8_t **poutbuf, int *poutbuf_size, 26 const uint8_t *buf, int buf_size, int keyframe){ 27 unsigned int *state= bsfc->priv_data; 28 int amount= args ? atoi(args) : (*state % 10001+1); 29 int i; 30 31 *poutbuf= av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE); 32 33 memcpy(*poutbuf, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE); 34 for(i=0; i<buf_size; i++){ 35 (*state) += (*poutbuf)[i] + 1; 36 if(*state % amount == 0) 37 (*poutbuf)[i] = *state; 38 } 39 return 1; 40} 41 42AVBitStreamFilter noise_bsf={ 43 "noise", 44 sizeof(int), 45 noise, 46}; 47