tools/cws2fws.c

   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 <sys/stat.h>
  10 #include <fcntl.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <zlib.h>
  15
  16 #ifdef DEBUG
  17 #define dbgprintf printf
  18 #else
  19 #define dbgprintf(...)
  20 #endif
  21
  22 int main(int argc, char *argv[])
  23 {
  24     int fd_in, fd_out, comp_len, uncomp_len, i, last_out;
  25     char buf_in[1024], buf_out[65536];
  26     z_stream zstream;
  27     struct stat statbuf;
  28
  29     if (argc < 3) {
  30         printf("Usage: %s <infile.swf> <outfile.swf>\n", argv[0]);
  31         return 1;
  32     }
  33
  34     fd_in = open(argv[1], O_RDONLY);
  35     if (fd_in < 0) {
  36         perror("Error opening input file");
  37         return 1;
  38     }
  39
  40     fd_out = open(argv[2], O_WRONLY | O_CREAT, 00644);
  41     if (fd_out < 0) {
  42         perror("Error opening output file");
  43         close(fd_in);
  44         return 1;
  45     }
  46
  47     if (read(fd_in, &buf_in, 8) != 8) {
  48         printf("Header error\n");
  49         close(fd_in);
  50         close(fd_out);
  51         return 1;
  52     }
  53
  54     if (buf_in[0] != 'C' || buf_in[1] != 'W' || buf_in[2] != 'S') {
  55         printf("Not a compressed flash file\n");
  56         return 1;
  57     }
  58
  59     fstat(fd_in, &statbuf);
  60     comp_len   = statbuf.st_size;
  61     uncomp_len = buf_in[4] | (buf_in[5] << 8) | (buf_in[6] << 16) | (buf_in[7] << 24);
  62
  63     printf("Compressed size: %d Uncompressed size: %d\n",
  64            comp_len - 4, uncomp_len - 4);
  65
  66     // write out modified header
  67     buf_in[0] = 'F';
  68     if (write(fd_out, &buf_in, 8) < 8) {
  69         perror("Error writing output file");
  70         return 1;
  71     }
  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         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             printf("Error while decompressing: %d\n", ret);
  93             inflateEnd(&zstream);
  94             return 1;
  95         }
  96
  97         dbgprintf("a_in: %d t_in: %lu a_out: %d t_out: %lu -- %lu out\n",
  98                   zstream.avail_in, zstream.total_in, zstream.avail_out,
  99                   zstream.total_out, zstream.total_out - last_out);
 100
 101         if (write(fd_out, &buf_out, zstream.total_out - last_out) <
 102             zstream.total_out - last_out) {
 103             perror("Error writing output file");
 104             return 1;
 105         }
 106
 107         i += len;
 108
 109         if (ret == Z_STREAM_END || ret == Z_BUF_ERROR)
 110             break;
 111     }
 112
 113     if (zstream.total_out != uncomp_len - 8) {
 114         printf("Size mismatch (%lu != %d), updating header...\n",
 115                zstream.total_out, uncomp_len - 8);
 116
 117         buf_in[0] =  (zstream.total_out + 8)        & 0xff;
 118         buf_in[1] = ((zstream.total_out + 8) >>  8) & 0xff;
 119         buf_in[2] = ((zstream.total_out + 8) >> 16) & 0xff;
 120         buf_in[3] = ((zstream.total_out + 8) >> 24) & 0xff;
 121
 122         lseek(fd_out, 4, SEEK_SET);
 123         if (write(fd_out, &buf_in, 4) < 4) {
 124             perror("Error writing output file");
 125             return 1;
 126         }
 127     }
 128
 129     inflateEnd(&zstream);
 130     close(fd_in);
 131     close(fd_out);
 132     return 0;
 133 }