tools/cws2fws.c
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00001 /*
00002  * cws2fws by Alex Beregszaszi
00003  * This file is placed in the public domain.
00004  * Use the program however you see fit.
00005  *
00006  * This utility converts compressed Macromedia Flash files to uncompressed ones.
00007  */
00008 
00009 #include <sys/stat.h>
00010 #include <fcntl.h>
00011 #include <stdio.h>
00012 #include <stdlib.h>
00013 #include <unistd.h>
00014 #include <zlib.h>
00015 
00016 #ifdef DEBUG
00017 #define dbgprintf printf
00018 #else
00019 #define dbgprintf(...)
00020 #endif
00021 
00022 int main(int argc, char *argv[])
00023 {
00024     int fd_in, fd_out, comp_len, uncomp_len, i, last_out;
00025     char buf_in[1024], buf_out[65536];
00026     z_stream zstream;
00027     struct stat statbuf;
00028 
00029     if (argc < 3) {
00030         printf("Usage: %s <infile.swf> <outfile.swf>\n", argv[0]);
00031         return 1;
00032     }
00033 
00034     fd_in = open(argv[1], O_RDONLY);
00035     if (fd_in < 0) {
00036         perror("Error opening input file");
00037         return 1;
00038     }
00039 
00040     fd_out = open(argv[2], O_WRONLY | O_CREAT, 00644);
00041     if (fd_out < 0) {
00042         perror("Error opening output file");
00043         close(fd_in);
00044         return 1;
00045     }
00046 
00047     if (read(fd_in, &buf_in, 8) != 8) {
00048         printf("Header error\n");
00049         close(fd_in);
00050         close(fd_out);
00051         return 1;
00052     }
00053 
00054     if (buf_in[0] != 'C' || buf_in[1] != 'W' || buf_in[2] != 'S') {
00055         printf("Not a compressed flash file\n");
00056         return 1;
00057     }
00058 
00059     fstat(fd_in, &statbuf);
00060     comp_len   = statbuf.st_size;
00061     uncomp_len = buf_in[4] | (buf_in[5] << 8) | (buf_in[6] << 16) | (buf_in[7] << 24);
00062 
00063     printf("Compressed size: %d Uncompressed size: %d\n",
00064            comp_len - 4, uncomp_len - 4);
00065 
00066     // write out modified header
00067     buf_in[0] = 'F';
00068     if (write(fd_out, &buf_in, 8) < 8) {
00069         perror("Error writing output file");
00070         return 1;
00071     }
00072 
00073     zstream.zalloc = NULL;
00074     zstream.zfree  = NULL;
00075     zstream.opaque = NULL;
00076     inflateInit(&zstream);
00077 
00078     for (i = 0; i < comp_len - 8;) {
00079         int ret, len = read(fd_in, &buf_in, 1024);
00080 
00081         dbgprintf("read %d bytes\n", len);
00082 
00083         last_out = zstream.total_out;
00084 
00085         zstream.next_in   = &buf_in[0];
00086         zstream.avail_in  = len;
00087         zstream.next_out  = &buf_out[0];
00088         zstream.avail_out = 65536;
00089 
00090         ret = inflate(&zstream, Z_SYNC_FLUSH);
00091         if (ret != Z_STREAM_END && ret != Z_OK) {
00092             printf("Error while decompressing: %d\n", ret);
00093             inflateEnd(&zstream);
00094             return 1;
00095         }
00096 
00097         dbgprintf("a_in: %d t_in: %lu a_out: %d t_out: %lu -- %lu out\n",
00098                   zstream.avail_in, zstream.total_in, zstream.avail_out,
00099                   zstream.total_out, zstream.total_out - last_out);
00100 
00101         if (write(fd_out, &buf_out, zstream.total_out - last_out) <
00102             zstream.total_out - last_out) {
00103             perror("Error writing output file");
00104             return 1;
00105         }
00106 
00107         i += len;
00108 
00109         if (ret == Z_STREAM_END || ret == Z_BUF_ERROR)
00110             break;
00111     }
00112 
00113     if (zstream.total_out != uncomp_len - 8) {
00114         printf("Size mismatch (%lu != %d), updating header...\n",
00115                zstream.total_out, uncomp_len - 8);
00116 
00117         buf_in[0] =  (zstream.total_out + 8)        & 0xff;
00118         buf_in[1] = ((zstream.total_out + 8) >>  8) & 0xff;
00119         buf_in[2] = ((zstream.total_out + 8) >> 16) & 0xff;
00120         buf_in[3] = ((zstream.total_out + 8) >> 24) & 0xff;
00121 
00122         lseek(fd_out, 4, SEEK_SET);
00123         if (write(fd_out, &buf_in, 4) < 4) {
00124             perror("Error writing output file");
00125             return 1;
00126         }
00127     }
00128 
00129     inflateEnd(&zstream);
00130     close(fd_in);
00131     close(fd_out);
00132     return 0;
00133 }