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cws2fws.c
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1 /*
2  * cws2fws by Alex Beregszaszi
3  * This file is placed in the public domain.
4  * Use the program however you see fit.
5  *
6  * This utility converts compressed Macromedia Flash files to uncompressed ones.
7  */
8 
9 #include "config.h"
10 #include <sys/stat.h>
11 #include <fcntl.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #if HAVE_IO_H
18 #include <io.h>
19 #endif
20 #include <zlib.h>
21 
22 #ifdef DEBUG
23 #define dbgprintf printf
24 #else
25 #define dbgprintf(...)
26 #endif
27 
28 int main(int argc, char *argv[])
29 {
30  int fd_in, fd_out, comp_len, uncomp_len, i, last_out;
31  char buf_in[1024], buf_out[65536];
32  z_stream zstream;
33  struct stat statbuf;
34 
35  if (argc < 3) {
36  printf("Usage: %s <infile.swf> <outfile.swf>\n", argv[0]);
37  return 1;
38  }
39 
40  fd_in = open(argv[1], O_RDONLY);
41  if (fd_in < 0) {
42  perror("Error opening input file");
43  return 1;
44  }
45 
46  fd_out = open(argv[2], O_WRONLY | O_CREAT, 00644);
47  if (fd_out < 0) {
48  perror("Error opening output file");
49  close(fd_in);
50  return 1;
51  }
52 
53  if (read(fd_in, &buf_in, 8) != 8) {
54  printf("Header error\n");
55  close(fd_in);
56  close(fd_out);
57  return 1;
58  }
59 
60  if (buf_in[0] != 'C' || buf_in[1] != 'W' || buf_in[2] != 'S') {
61  printf("Not a compressed flash file\n");
62  return 1;
63  }
64 
65  if (fstat(fd_in, &statbuf) < 0) {
66  perror("fstat failed");
67  return 1;
68  }
69  comp_len = statbuf.st_size;
70  uncomp_len = buf_in[4] | (buf_in[5] << 8) | (buf_in[6] << 16) | (buf_in[7] << 24);
71 
72  printf("Compressed size: %d Uncompressed size: %d\n",
73  comp_len - 4, uncomp_len - 4);
74 
75  // write out modified header
76  buf_in[0] = 'F';
77  if (write(fd_out, &buf_in, 8) < 8) {
78  perror("Error writing output file");
79  return 1;
80  }
81 
82  zstream.zalloc = NULL;
83  zstream.zfree = NULL;
84  zstream.opaque = NULL;
85  if (inflateInit(&zstream) != Z_OK) {
86  fprintf(stderr, "inflateInit failed\n");
87  return 1;
88  }
89 
90  for (i = 0; i < comp_len - 8;) {
91  int ret, len = read(fd_in, &buf_in, 1024);
92 
93  dbgprintf("read %d bytes\n", len);
94 
95  last_out = zstream.total_out;
96 
97  zstream.next_in = &buf_in[0];
98  zstream.avail_in = len;
99  zstream.next_out = &buf_out[0];
100  zstream.avail_out = 65536;
101 
102  ret = inflate(&zstream, Z_SYNC_FLUSH);
103  if (ret != Z_STREAM_END && ret != Z_OK) {
104  printf("Error while decompressing: %d\n", ret);
105  inflateEnd(&zstream);
106  return 1;
107  }
108 
109  dbgprintf("a_in: %d t_in: %lu a_out: %d t_out: %lu -- %lu out\n",
110  zstream.avail_in, zstream.total_in, zstream.avail_out,
111  zstream.total_out, zstream.total_out - last_out);
112 
113  if (write(fd_out, &buf_out, zstream.total_out - last_out) <
114  zstream.total_out - last_out) {
115  perror("Error writing output file");
116  return 1;
117  }
118 
119  i += len;
120 
121  if (ret == Z_STREAM_END || ret == Z_BUF_ERROR)
122  break;
123  }
124 
125  if (zstream.total_out != uncomp_len - 8) {
126  printf("Size mismatch (%lu != %d), updating header...\n",
127  zstream.total_out, uncomp_len - 8);
128 
129  buf_in[0] = (zstream.total_out + 8) & 0xff;
130  buf_in[1] = ((zstream.total_out + 8) >> 8) & 0xff;
131  buf_in[2] = ((zstream.total_out + 8) >> 16) & 0xff;
132  buf_in[3] = ((zstream.total_out + 8) >> 24) & 0xff;
133 
134  if ( lseek(fd_out, 4, SEEK_SET) < 0
135  || write(fd_out, &buf_in, 4) < 4) {
136  perror("Error writing output file");
137  return 1;
138  }
139  }
140 
141  inflateEnd(&zstream);
142  close(fd_in);
143  close(fd_out);
144  return 0;
145 }