release/src-rt-6.x.4708/router/ffmpeg/tools/trasher.c

   1 /*
   2  * Copyright (c) 2007 Michael Niedermayer
   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 <stdio.h>
  22 #include <stdlib.h>
  23 #include <inttypes.h>
  24
  25 static uint32_t state;
  26 static uint32_t ran(void){
  27     return state= state*1664525+1013904223;
  28 }
  29
  30 int main(int argc, char** argv)
  31 {
  32     FILE *f;
  33     int count, maxburst, length;
  34
  35     if (argc < 5){
  36         printf("USAGE: trasher <filename> <count> <maxburst> <seed>\n");
  37         return 1;
  38     }
  39
  40     f= fopen(argv[1], "rb+");
  41     if (!f){
  42         perror(argv[1]);
  43         return 2;
  44     }
  45     count= atoi(argv[2]);
  46     maxburst= atoi(argv[3]);
  47     state= atoi(argv[4]);
  48
  49     fseek(f, 0, SEEK_END);
  50     length= ftell(f);
  51     fseek(f, 0, SEEK_SET);
  52
  53     while(count--){
  54         int burst= 1 + ran() * (uint64_t) (abs(maxburst)-1) / UINT32_MAX;
  55         int pos= ran() * (uint64_t) length / UINT32_MAX;
  56         fseek(f, pos, SEEK_SET);
  57
  58         if(maxburst<0) burst= -maxburst;
  59
  60         if(pos + burst > length)
  61             continue;
  62
  63         while(burst--){
  64             int val= ran() * 256ULL / UINT32_MAX;
  65
  66             if(maxburst<0) val=0;
  67
  68             fwrite(&val, 1, 1, f);
  69         }
  70     }
  71
  72     return 0;
  73 }