Sphere360 / README.md
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---
task_categories:
- audio-to-audio
language:
- en
tags:
- spatial-audio
- ambisonics
- 360-video
- audio-visual
size_categories:
- 1K<n<10K
---
# Sphere360
Paired **first-order ambisonic audio** and **360° equirectangular video**, sourced
from YouTube. Each pair shares one ID, so the spatial sound field and the visual
sphere are aligned by construction. 791 hours of paired material.
| | Pairs | Audio | Video | Size |
|---|---|---|---|---|
| `train` | 5,469 | 5,469 | 5,469 | 5.24 TB |
| `test` | 162 | 162 | 162 | 0.17 TB |
| `extras` | — | 415 | 110 | 0.25 TB |
| **Total** | **5,631** | **6,046** | **5,741** | **5.66 TB** |
**Audio** — Opus, 48 kHz, 4-channel first-order ambisonics (`ambisonic 1`).
Every audio file in the dataset is verified to carry exactly this layout.
**Video** — VP9 equirectangular. It also carries a stereo track that is *not* the
spatial audio; always take the ambisonics from `audio/`.
## Layout
```
audio/{train,test}/{00..63}/<id>.webm ambisonic audio
video/{train,test}/{00..63}/<id>.webm 360° video
extras/audio_only/{train,test}/<id>.webm unpaired
extras/video_only/{train,test}/<id>.webm unpaired
metadata/{train,test,extras}.jsonl one row per ID
metadata/stats.json counts, and every file excluded and why
```
The 64 shards keep each directory to ~184 files and leave room to grow. Shard is
derived from the ID, so no lookup is needed:
```python
import hashlib
shard = lambda vid: f"{int(hashlib.sha1(vid.encode()).hexdigest()[:8], 16) % 64:02d}"
shard("-EOhDHns4xw") # -> "00"
```
Shards are hashed rather than cut from the ID's first characters because YouTube
IDs are case-sensitive and would collide on case-insensitive filesystems.
## Use
Extensions vary, so read paths from the metadata rather than building them:
```python
import json
from huggingface_hub import hf_hub_download
R = "OmniAV/Sphere360"
rows = [json.loads(l) for l in open(hf_hub_download(R, "metadata/train.jsonl", repo_type="dataset"))]
r = rows[0]
audio = hf_hub_download(R, r["audio"]["path"], repo_type="dataset")
video = hf_hub_download(R, r["video"]["path"], repo_type="dataset")
```
One row:
```json
{"id": "-EOhDHns4xw", "split": "train", "shard": "00", "paired": true,
"youtube_url": "https://www.youtube.com/watch?v=-EOhDHns4xw",
"audio": {"path": "audio/train/00/-EOhDHns4xw.webm", "bytes": 11536470,
"duration": 255.981, "codec": "opus", "channels": 4,
"channel_layout": "ambisonic 1", "sample_rate": 48000,
"sha256": "6e4f14c2cb0c0790..."},
"video": {"path": "video/train/00/-EOhDHns4xw.webm", "bytes": 557769482,
"duration": 256.008, "codec": "vp9", "width": 3840, "height": 2160,
"sha256": "..."}}
```
Every entry carries `bytes` and `sha256`, so a download can be checked without
trusting the transfer:
```python
import hashlib
h = hashlib.sha256(open(audio, "rb").read()).hexdigest()
assert h == r["audio"]["sha256"]
```
Pull one shard instead of 5.66 TB:
```bash
hf download OmniAV/Sphere360 --repo-type dataset --include "audio/train/00/*" "video/train/00/*"
```
## Know before you train
- **Resolution is not uniform** — 56 distinct sizes. 3840×2160 (44%), 3840×1920
(28%) and 3840×2048 (9%) cover most of it, but the range runs from 1920×960 to
7680×4320. This reflects the sources, not a processing error. Filter on
`width`/`height` if your pipeline needs one size.
- **Duration is not uniform** — 12 s to 11.4 h, median 277 s. Clip as needed.
- **`extras/` is unpaired** and excluded from `train`/`test`. Single-modality use
only.
- **30 files were dropped**, each a low-bitrate video rendition the fetcher had
written into the audio slot when the ambisonic track was unavailable. They
contained no audio stream at all. Their IDs are listed in
`metadata/stats.json` under `rejected_files`; the 27 that still had real video
moved to `extras/video_only/`.
- Material was fetched twice in parallel. Where both runs returned an ID, the
higher-resolution copy won, with file size breaking ties at equal resolution.
- Every row carries `youtube_url`, so any file can be traced to its source.
## Availability
All 64 shards are published — 11,787 files, 5.66 TB. `metadata/*.jsonl` lists
only rows whose files are actually present, and `metadata/stats.json` records the
live set under `published_shards` / `published_rows`, so a run driven by the
metadata never asks for a missing file.
## Citation
Derived from the Sphere360 dataset introduced in OmniAudio.
```bibtex
@inproceedings{omniaudio2025,
title = {OmniAudio: Generating Spatial Audio from 360-Degree Video},
booktitle = {International Conference on Machine Learning (ICML)},
year = {2025}
}
```