Fix aloha_dora_format

lerobot/common/datasets/push_dataset_to_hub/aloha_dora_format.py

@@ -18,6 +18,7 @@ Contains utilities to process raw data format from dora-record
 """
 
 import logging
+import re
 from pathlib import Path
 
 import pandas as pd
@@ -50,9 +51,7 @@ def load_from_raw(raw_dir: Path, out_dir: Path, fps: int):
     df = reference_df
     for path in raw_dir.glob("*.parquet"):
         key = path.stem  # action or observation.state or ...
-        if key == reference_key:
+        if key == reference_key or "failed_episode_index" in key:
-            continue
-        elif "failed_episode_index" in key:
             continue
         modality_df = pd.read_parquet(path)
         modality_df = modality_df[["timestamp_utc", key]]
@@ -64,15 +63,28 @@ def load_from_raw(raw_dir: Path, out_dir: Path, fps: int):
             tolerance=pd.Timedelta(f"{1/fps} seconds"),
         )
 
-    # Remove rows with a NaN in any column. It can happened during the first frames of an episode,
-    # because some cameras didnt start recording yet.
-    df = df.dropna(axis=0)
-
     # Remove rows with episode_index -1 which indicates data that correspond to in-between episodes
     df = df[df["episode_index"] != -1]
 
+    image_keys = [key for key in df if "observation.images." in key]
+
+    def get_episode_index(row):
+        episode_index_per_cam = {}
+        for key in image_keys:
+            path = row[key][0]["path"]
+            match = re.search(r"_(\d{6}).mp4", path)
+            if not match:
+                raise ValueError(path)
+            episode_index = int(match.group(1))
+            episode_index_per_cam[key] = episode_index
+        assert (
+            len(set(episode_index_per_cam.values())) == 1
+        ), f"All cameras are expected to belong to the same episode, but getting {episode_index_per_cam}"
+        return episode_index
+
+    df["episode_index"] = df.apply(get_episode_index, axis=1)
+
     # dora only use arrays, so single values are encapsulated into a list
-    df["episode_index"] = df["episode_index"].map(lambda x: x[0])
     df["frame_index"] = df.groupby("episode_index").cumcount()
     df = df.reset_index()
     df["index"] = df.index