cws2fws.c

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