diff --git a/README.md b/README.md
index 581184d..45351d1 100644
--- a/README.md
+++ b/README.md
@@ -9,15 +9,20 @@ Author: JunJie Jiang
 ## Interface
 
 ```python
-__init__(self, key_frame: bool)
+__init__(self, start_time=None, end_time=None, sample_type=None, args=None)
 ```
 
 Args:
 
-- key_frame:
+- start_time: float
+- end_time: float
+  decode video [start_time, end_time)
+
+  sample_type:
+        uniform_temporal_subsample
+        args:
+                num_samples: int
 
-  True: Only return key frame
-  False: Return all image frames of video
 
 ```python
 __call__(self, video_path: str)
@@ -38,6 +43,23 @@ av
 
 ## How it works
 
+from towhee import ops
+
+d = ops.video_decode.ffmpeg(start_time=10.0, end_time=20.0, sample_type='uniform_temporal_subsample', args={'num_samples': 10})
+for frame in d(video_path):
+    print(frame)
+
+result:
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776310>, TIMESTAMP=10010)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776700>, TIMESTAMP=11078)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776310>, TIMESTAMP=12145)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776700>, TIMESTAMP=13280)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776310>, TIMESTAMP=14348)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776700>, TIMESTAMP=15482)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776310>, TIMESTAMP=16550)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776700>, TIMESTAMP=17684)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776310>, TIMESTAMP=18752)
+Outputs(image=<towhee.types.image.Image object at 0x7fa444776700>, TIMESTAMP=19887)
 
 
 ## Reference