cws2fws.c

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