Fix for overflow issue in mpegvideo.c patch by (Martin Boehme: boehme, inb uni-luebec...
[ffmpeg.git] / 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[1024];
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-4;)
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 = 1024;
88                 
89         ret = inflate(&zstream, Z_SYNC_FLUSH);
90         if (ret == Z_STREAM_END || ret == Z_BUF_ERROR)
91             break;
92         if (ret != Z_OK)
93         {
94             printf("Error while decompressing: %d\n", ret);
95             inflateEnd(&zstream);
96             exit(1);
97         }
98         
99         dbgprintf("a_in: %d t_in: %d a_out: %d t_out: %d -- %d out\n",
100             zstream.avail_in, zstream.total_in, zstream.avail_out, zstream.total_out,
101             zstream.total_out-last_out);
102         
103         write(fd_out, &buf_out, zstream.total_out-last_out);
104
105         i += len;
106     }
107     
108     if (zstream.total_out != uncomp_len-8)
109     {
110         printf("Size mismatch (%d != %d), updating header...\n",
111             zstream.total_out, uncomp_len-8);
112
113         buf_in[0] = (zstream.total_out+8) & 0xff;
114         buf_in[1] = (zstream.total_out+8 >> 8) & 0xff;
115         buf_in[2] = (zstream.total_out+8 >> 16) & 0xff;
116         buf_in[3] = (zstream.total_out+8 >> 24) & 0xff;
117         
118         lseek(fd_out, 4, SEEK_SET);
119         write(fd_out, &buf_in, 4);
120     }
121     
122     inflateEnd(&zstream);
123     close(fd_in);
124     close(fd_out);
125 }