update

Signed-off-by: junjie.jiang <junjie.jiang@zilliz.com>

README.md

@@ -22,7 +22,11 @@
 ```Python
 import towhee
 
-towhee.glob('./music.mp3').audio_decode().flatten().show(limit=1)
+towhee.glob('./music.mp3').audio_decode.ffmpeg().flatten().show(limit=1)
+
+
+# batch decode
+# towhee.glob('./music.mp3').audio_decode.ffmpeg(500).flatten().show(limit=1)
 
 ```
 
@@ -39,6 +43,10 @@ Create the operator via the following factory method:
 
 ***audio_decode.ffmpeg()***
 
+batch decode, batch_size = 100:
+
+***audio_decode.ffmpeg(100)***
+
 
 
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