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
25static uint32_t state;
26static uint32_t ran(void){
27    return state= state*1664525+1013904223;
28}
29
30int 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}
74