cws2fws.c

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