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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 "config.h"
10 #include <sys/stat.h>
11 #include <fcntl.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #if HAVE_IO_H
18 #include <io.h>
19 #endif
20 #include <zlib.h>
21 
22 #ifdef DEBUG
23 #define dbgprintf printf
24 #else
25 #define dbgprintf(...) do { if (0) printf(__VA_ARGS__); } while (0)
26 #endif
27 
main(int argc,char * argv[])28 int main(int argc, char *argv[])
29 {
30     int fd_in, fd_out, comp_len, uncomp_len, i, last_out;
31     char buf_in[1024], buf_out[65536];
32     z_stream zstream;
33     struct stat statbuf;
34     int ret = 1;
35 
36     if (argc < 3) {
37         printf("Usage: %s <infile.swf> <outfile.swf>\n", argv[0]);
38         return 1;
39     }
40 
41     fd_in = open(argv[1], O_RDONLY);
42     if (fd_in < 0) {
43         perror("Error opening input file");
44         return 1;
45     }
46 
47     fd_out = open(argv[2], O_WRONLY | O_CREAT, 00644);
48     if (fd_out < 0) {
49         perror("Error opening output file");
50         close(fd_in);
51         return 1;
52     }
53 
54     if (read(fd_in, &buf_in, 8) != 8) {
55         printf("Header error\n");
56         goto out;
57     }
58 
59     if (buf_in[0] != 'C' || buf_in[1] != 'W' || buf_in[2] != 'S') {
60         printf("Not a compressed flash file\n");
61         goto out;
62     }
63 
64     if (fstat(fd_in, &statbuf) < 0) {
65         perror("fstat failed");
66         return 1;
67     }
68     comp_len   = statbuf.st_size;
69     uncomp_len = buf_in[4] | (buf_in[5] << 8) | (buf_in[6] << 16) | (buf_in[7] << 24);
70 
71     printf("Compressed size: %d Uncompressed size: %d\n",
72            comp_len - 4, uncomp_len - 4);
73 
74     // write out modified header
75     buf_in[0] = 'F';
76     if (write(fd_out, &buf_in, 8) < 8) {
77         perror("Error writing output file");
78         goto out;
79     }
80 
81     zstream.zalloc = NULL;
82     zstream.zfree  = NULL;
83     zstream.opaque = NULL;
84     if (inflateInit(&zstream) != Z_OK) {
85         fprintf(stderr, "inflateInit failed\n");
86         return 1;
87     }
88 
89     for (i = 0; i < comp_len - 8;) {
90         int ret, len = read(fd_in, &buf_in, 1024);
91 
92         if (len == -1) {
93             printf("read failure\n");
94             inflateEnd(&zstream);
95             goto out;
96         }
97 
98         dbgprintf("read %d bytes\n", len);
99 
100         last_out = zstream.total_out;
101 
102         zstream.next_in   = &buf_in[0];
103         zstream.avail_in  = len;
104         zstream.next_out  = &buf_out[0];
105         zstream.avail_out = 65536;
106 
107         ret = inflate(&zstream, Z_SYNC_FLUSH);
108         if (ret != Z_STREAM_END && ret != Z_OK) {
109             printf("Error while decompressing: %d\n", ret);
110             inflateEnd(&zstream);
111             goto out;
112         }
113 
114         dbgprintf("a_in: %d t_in: %lu a_out: %d t_out: %lu -- %lu out\n",
115                   zstream.avail_in, zstream.total_in, zstream.avail_out,
116                   zstream.total_out, zstream.total_out - last_out);
117 
118         if (write(fd_out, &buf_out, zstream.total_out - last_out) <
119             zstream.total_out - last_out) {
120             perror("Error writing output file");
121             inflateEnd(&zstream);
122             goto out;
123         }
124 
125         i += len;
126 
127         if (ret == Z_STREAM_END || ret == Z_BUF_ERROR)
128             break;
129     }
130 
131     if (zstream.total_out != uncomp_len - 8) {
132         printf("Size mismatch (%lu != %d), updating header...\n",
133                zstream.total_out, uncomp_len - 8);
134 
135         buf_in[0] =  (zstream.total_out + 8)        & 0xff;
136         buf_in[1] = ((zstream.total_out + 8) >>  8) & 0xff;
137         buf_in[2] = ((zstream.total_out + 8) >> 16) & 0xff;
138         buf_in[3] = ((zstream.total_out + 8) >> 24) & 0xff;
139 
140         if (   lseek(fd_out, 4, SEEK_SET) < 0
141             || write(fd_out, &buf_in, 4) < 4) {
142             perror("Error writing output file");
143             inflateEnd(&zstream);
144             goto out;
145         }
146     }
147 
148     ret = 0;
149     inflateEnd(&zstream);
150 out:
151     close(fd_in);
152     close(fd_out);
153     return ret;
154 }
155