2007-02-06

CWS转FWS的C代码

原来的代码不能正常编译运行,我做了多处修改
应该是编译和运行环境不同造成的吧。我的环境是VC++2005


/*
* cws2fws by Alex Beregszaszi <alex@fsn.hu>
* Public domain.
*
* This utility converts compressed Macromedia Flash files to uncompressed ones.
*
*/

/*
* Modified by Wang Lu Feb. 6th, 2007
*/

#include <sys/stat.h>
#include <fcntl.h>
//#include <unistd.h> //WL: no this header file in VC++ 2005
#include "zlib.h"

#ifdef DEBUG
#define dbgprintf printf
#else
#define dbgprintf
#endif

#define NULL ((void*)0) //WL: Dummy

main(int argc, char *argv[])
{
int fd_in, fd_out, comp_len, uncomp_len, tag, i, last_out;
char buf_in[1024], buf_out[65536];
z_stream zstream;
struct stat statbuf;

if (argc < 3)
{
printf("Usage: %s <infile.swf> <outfile.swf>\n", argv[0]);
exit(1);
}

fd_in = open(argv[1], O_RDONLY|O_BINARY); //WL: there wasn't O_BINARY originally, and didn't work correctly under VC++
if (fd_in < 0)
{
perror("Error while opening: ");
exit(1);
}

fd_out = open(argv[2], O_WRONLY|O_CREAT|O_BINARY, 00644); //WL: there wasn't O_BINARY originally, and didn't work correctly under VC++
if (fd_out < 0)
{
perror("Error while opening: ");
close(fd_in);
exit(1);
}

if (read(fd_in, buf_in, 8) != 8)
{
printf("Header error\n");
close(fd_in);
close(fd_out);
exit(1);
}

if (buf_in[0] != 'C' || buf_in[1] != 'W' || buf_in[2] != 'S')
{
printf("Not a compressed flash file\n");
exit(1);
}

fstat(fd_in, &statbuf);
comp_len = statbuf.st_size;

//WL: old code is: (which didn't work correctly)
//may because of the convertion from char to unsigned int, VC++ makes 0x83 into 0xffffff83
// uncomp_len = buf_in[4] | (buf_in[5] << 8) | (buf_in[6] << 16) | (buf_in[7] << 24);
uncomp_len = (buf_in[4]&0xff) | ((buf_in[5]&0xff) << 8) | ((buf_in[6]&0xff) << 16) | ((buf_in[7]&0xff) << 24);

printf("Compressed size: %d Uncompressed size: %u\n", comp_len-4, uncomp_len-4);

// write out modified header
buf_in[0] = 'F';
write(fd_out, buf_in, 8);

zstream.zalloc = NULL;
zstream.zfree = NULL;
zstream.opaque = NULL;
inflateInit(&zstream);

for (i = 0; i < comp_len-8;)
{
int ret, len = read(fd_in, buf_in, 1024);

dbgprintf("read %d bytes\n", len);

last_out = zstream.total_out;

zstream.next_in = &buf_in[0];
zstream.avail_in = len;
zstream.next_out = &buf_out[0];
zstream.avail_out = 65536;

ret = inflate(&zstream, Z_SYNC_FLUSH);
if (ret != Z_STREAM_END && ret != Z_OK)
{
printf("Error while decompressing: %d\n", ret);
inflateEnd(&zstream);
exit(1);
}

dbgprintf("a_in: %d t_in: %d a_out: %d t_out: %d -- %d out\n",
zstream.avail_in, zstream.total_in, zstream.avail_out, zstream.total_out,
zstream.total_out-last_out);

write(fd_out, &buf_out, zstream.total_out-last_out);

i += len;

if (ret == Z_STREAM_END || ret == Z_BUF_ERROR)
break;
}

if (zstream.total_out != uncomp_len-8)
{
printf("Size mismatch (%d != %d), updating header...\n",
zstream.total_out, uncomp_len-8);

buf_in[0] = (zstream.total_out+8) & 0xff;
buf_in[1] = (zstream.total_out+8 >> 8) & 0xff;
buf_in[2] = (zstream.total_out+8 >> 16) & 0xff;
buf_in[3] = (zstream.total_out+8 >> 24) & 0xff;

lseek(fd_out, 4, SEEK_SET);
write(fd_out, &buf_in, 4);
}

inflateEnd(&zstream);
close(fd_in);
close(fd_out);
}
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