/*
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* 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
*/
#include <stdlib.h>
#include <string.h>
#include "avcodec.h"
#include "libavutil/mem.h"
static int noise(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args,
uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size, int keyframe){
unsigned int *state= bsfc->priv_data;
int amount
= args
? atoi(args
) : (*state
% 10001+1); int i;
if(amount <= 0)
return AVERROR(EINVAL);
*poutbuf= av_malloc(buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
if (!*poutbuf)
return AVERROR(ENOMEM);
memcpy(*poutbuf
, buf
, buf_size
+ FF_INPUT_BUFFER_PADDING_SIZE
); for(i=0; i<buf_size; i++){
(*state) += (*poutbuf)[i] + 1;
if(*state % amount == 0)
(*poutbuf)[i] = *state;
}
return 1;
}
AVBitStreamFilter ff_noise_bsf={
.name = "noise",
.priv_data_size = sizeof(int),
.filter = noise,
};