update readme

Author: Skylark0924

rofunc/README.md

@@ -12,6 +12,7 @@
     - [Zed](#zed)
       - [Record](#record)
       - [Playback](#playback)
+      - [Export](#export)
 
 ## Hello, robot world!
 
@@ -35,7 +36,7 @@ import rofunc as rf
 |                |             | `optitrack.visualize` | Show or save gif about the motion                    |        |
 |                | ZED         | `zed.record`          | Record with multiple cameras                         | ✅      |
 |                |             | `zed.playback`        | Playback the recording and save snapshots            | ✅      |
-|                |             | `zed.export`          | Export the recording to mp4                          |        |
+|                |             | `zed.export`          | Export the recording to .avi and image sequence      | ✅      |
 |                | Multi-modal | `mmodal.record`       | Record multi-modal demonstration data simultaneously |        |
 | **Logger**     |             | `logger.write`        | Custom tensorboard-based logger                      |        |
 | **Coordinate** |             | `coord.custom_class`  | Define the custom class of `Pose`                    |        |
@@ -200,4 +201,42 @@ Saving image 1.png : SUCCESS
 Saving image 2.png : SUCCESS
 Saving image 3.png : SUCCESS
 ...
-```
+```
+
+#### Export
+```python
+def export(filepath, mode=1):
+    """
+    Export the svo file with specific mode.
+    Args:
+        filepath: SVO file path (input) : path/to/file.svo
+        mode: Export mode:  0=Export LEFT+RIGHT AVI.
+                            1=Export LEFT+DEPTH_VIEW AVI.
+                            2=Export LEFT+RIGHT image sequence.
+                            3=Export LEFT+DEPTH_VIEW image sequence.
+                            4=Export LEFT+DEPTH_16Bit image sequence.
+
+    Returns:
+
+    """
+```
+
+Example
+```python
+import rofunc as rf
+
+rf.zed.export('/home/ubuntu/Data/06_24/Video/20220624_1649/38709363.svo', 2)
+```
+
+> Since the converting always take a long time, I provide the batch form to convert in parallel. 
+
+```python
+def export_batch(filedir, all_mode=True, mode=None, core_num=10):
+```
+
+Example:
+```
+rf.zed.export_batch('/home/ubuntu/Data/06_24/Video/20220624_1649', core_num=20)
+```
+
+Then you can convert all the .svo files under the specific directory with all mode in parallel. Enjoy it!