diff --git a/WechatImageDecoder.py b/WechatImageDecoder.py
index 7eb0cf4..0b33db8 100644
--- a/WechatImageDecoder.py
+++ b/WechatImageDecoder.py
@@ -3,14 +3,15 @@
 
 import re
 
+
 class WechatImageDecoder:
-    def __init__(self, dat_file):
+    def __init__(self, dat_file, out_file):
         dat_file = dat_file.lower()
 
-        decoder = self._match_decoder(dat_file)
-        decoder(dat_file)
+        decoder = self._match_decoder(dat_file, out_file)
+        decoder(dat_file, out_file)
 
-    def _match_decoder(self, dat_file):
+    def _match_decoder(self, dat_file, out_file):
         decoders = {
             r'.+\.dat$': self._decode_pc_dat,
             r'cache\.data\.\d+$': self._decode_android_dat,
@@ -22,14 +23,14 @@ def _match_decoder(self, dat_file):
                 return v
         return decoders[None]
 
-    def _decode_pc_dat(self, dat_file):
-        
+    def _decode_pc_dat(self, dat_file, out_file):
+
         def do_magic(header_code, buf):
             return header_code ^ list(buf)[0] if buf else 0x00
-        
+
         def decode(magic, buf):
             return bytearray([b ^ magic for b in list(buf)])
-            
+
         def guess_encoding(buf):
             headers = {
                 'jpg': (0xff, 0xd8),
@@ -37,24 +38,24 @@ def guess_encoding(buf):
                 'gif': (0x47, 0x49),
             }
             for encoding in headers:
-                header_code, check_code = headers[encoding] 
+                header_code, check_code = headers[encoding]
                 magic = do_magic(header_code, buf)
                 _, code = decode(magic, buf[:2])
                 if check_code == code:
                     return (encoding, magic)
             print('Decode failed')
-            sys.exit(1) 
+            sys.exit(1)
 
         with open(dat_file, 'rb') as f:
             buf = bytearray(f.read())
         file_type, magic = guess_encoding(buf)
 
-        img_file = re.sub(r'.dat$', '.' + file_type, dat_file)
+        img_file = out_file + '.' + file_type
         with open(img_file, 'wb') as f:
             new_buf = decode(magic, buf)
             f.write(new_buf)
 
-    def _decode_android_dat(self, dat_file):
+    def _decode_android_dat(self, dat_file, out_file):
         with open(dat_file, 'rb') as f:
             buf = f.read()
 
@@ -63,7 +64,7 @@ def _decode_android_dat(self, dat_file):
             if m.start() == 0:
                 continue
 
-            imgfile = '%s_%d.jpg' % (dat_file, i)
+            imgfile = '%s_%d.jpg' % (out_file, i)
             with open(imgfile, 'wb') as f:
                 f.write(buf[last_index: m.start()])
             last_index = m.start()
@@ -74,23 +75,29 @@ def _decode_unknown_dat(self, dat_file):
 
 if __name__ == '__main__':
     import sys
-    if len(sys.argv) != 2:
+    if len(sys.argv) >= 4:
         print('\n'.join([
             'Usage:',
-            '  python WechatImageDecoder.py [dat_file]',
+            '  python WechatImageDecoder.py [dat_file] ([out_filepath])',
             '',
             'Example:',
             '  # PC:',
-            '  python WechatImageDecoder.py 1234567890.dat',
+            '  python WechatImageDecoder.py 1234567890.dat path/to/foo/filename',
+            '  the true suffix will be added automatically',
             '',
             '  # Android:',
-            '  python WechatImageDecoder.py cache.data.10'
+            '  python WechatImageDecoder.py cache.data.10 path/to/foo/filename'
         ]))
         sys.exit(1)
 
     _,  dat_file = sys.argv[:2]
+    print(dat_file)
+    try:
+        out_file = sys.argv[2]
+    except Exception:
+        out_file = sys.argv[1]
     try:
-        WechatImageDecoder(dat_file)
+        WechatImageDecoder(dat_file, out_file)
     except Exception as e:
         print(e)
         sys.exit(1)