azithromycin/ReubenLim_so101_ball_in_cup

SO101 Ball in Cup TsFile

This is an Apache TsFile conversion of ReubenLim/so101_ball_in_cup, a LeRobot v2.1 SO101 dataset for picking up a ball and placing it in a cup.

Source and provenance

• Original dataset: ReubenLim/so101_ball_in_cup
• Pinned source revision: 811ff35e5d324f666941ad289c06de4d13980538
• Repository owner, uploader, and commit author: Reuben Lim Yaw Hui (ReubenLim)
• License: Apache-2.0
• Paper/citation: not provided by the source repository
• Robot: so101; LeRobot codebase: v2.1
• Split: train; sampling frequency: 30 fps
• Task 0: Pick up the ball and place it in the cup.
• Scale: 61 episodes, 57,839 rows, one task, 61 source Parquet shards
• Source data path: data/chunk-{episode_chunk:03d}/episode_{episode_index:06d}.parquet

The source README still embeds an obsolete 23-episode info.json example. The counts above come from the pinned repository meta/info.json, all source Parquet footers, and the complete repository tree.

Converted artifact

• TsFile: data/reubenlim_so101_ball_in_cup.tsfile
• Table: reubenlim_so101_ball_in_cup
• Rows/devices: 57,839 / 61
• Time precision: milliseconds
• Source Parquet size: 2,754,715 bytes
• TsFile size: 780,173 bytes
• TsFile/source size ratio: 0.283214
• meta/ is preserved, with meta/info.json updated for this TsFile artifact.

Schema

Column or group	TsFile role	Type	Notes
Time	TIME	INT64	round(timestamp * 1000) ms; restarts at zero per episode
episode_index	TAG	STRING	Original integer value stored as a TsFile device/TAG segment
task_index	TAG	STRING	Original integer value stored as a TsFile device/TAG segment
frame_index	FIELD	INT64	Original per-episode frame index
sample_index	FIELD	INT64	Renamed from source index
action_0 ... action_5	FIELD	FLOAT	Flattened source action[6]
observation_state_0 ... observation_state_5	FIELD	FLOAT	Flattened source observation.state[6]

Vector prefixes preserve their source names, with . replaced by _.

Conversion details

• Time: TS_2DIFF + LZ4
• FLOAT/DOUBLE: GORILLA + LZ4
• INT32/INT64: TS_2DIFF + LZ4
• BOOLEAN: RLE + LZ4 when present; this source has no BOOLEAN field
• TAG values use the TsFile table-model device/tag mechanism.
• All train episodes are merged into one table and sorted by TAG columns and Time.
• Source timestamp is dropped because it is represented by Time / 1000 seconds.
• No numeric rows, action/state dimensions, frame indexes, episode indexes, or task indexes are dropped.
• Camera pixels are video assets rather than Parquet columns and are not embedded in TsFile.

Videos

Videos are not included in this TsFile dataset. The original repository stores 183 frame-aligned AV1 MP4 files: 61 episodes for each of the front, overhead, and side streams under videos/chunk-000/. The exact template is videos/chunk-{episode_chunk:03d}/{video_key}/episode_{episode_index:06d}.mp4. The source videos total 1,585,929,900 bytes and are 640x480 at 30 fps without audio. Stream sizes are 573,779,857 bytes (front), 483,143,898 bytes (overhead), and 529,006,145 bytes (side). Use episode_index and frame_index to align TsFile rows with all three views.

Validation

Local validation read all 57,839 rows with the Apache TsFile Java reader, checked the physical codecs, TAG schema, per-episode Time ordering, vector widths, duplicate TAG+Time keys, and the source/staged/TsFile row counts. The conversion script and validation reports stay local and are not part of the upload-ready dataset directory.

Minimal read example

from tsfile import TsFileReader

reader = TsFileReader("data/reubenlim_so101_ball_in_cup.tsfile")
columns = [
    "episode_index",
    "task_index",
    "frame_index",
    "sample_index",
    "action_0",
    "observation_state_0",
]
with reader.query_table("reubenlim_so101_ball_in_cup", columns, batch_size=65536) as result:
    batch = result.read_arrow_batch()
    print(batch.to_pandas().head())
reader.close()

Citation

The source repository provides no formal citation. Cite the original Hugging Face dataset and its repository author Reuben Lim Yaw Hui (ReubenLim) when using this conversion.