--- license: other license_name: mixed-per-dataset license_link: LICENSE language: - en tags: - text-to-speech - tts - speech - audio - open-data - training-data - english task_categories: - text-to-speech pretty_name: Raon-OpenTTS-Pool size_categories: - 100M

Technical Report (Coming soon)

**Raon-OpenTTS-Pool** is a large-scale open English speech corpus for text-to-speech (TTS) training, constructed from 8 publicly available speech corpora and a set of web-sourced recordings. It is the training data behind [RAON-OpenTTS](https://github.com/krafton-ai/RAON-OpenTTS), an open TTS model that performs on par with state-of-the-art closed-data systems. - **615K hours** of speech audio - **239.7M** speech segments - **11 source datasets** aggregated into a unified format - All audio stored as **16 kHz mono Opus (64 kbps)** in [WebDataset](https://github.com/webdataset/webdataset) tar shards We restrict data sources to publicly available English speech datasets with more than 500 hours of audio. All speech segments are limited to **30 seconds or shorter** to reduce alignment errors, multi-speaker content, and non-speech artifacts. Existing public datasets (LibriHeavy, Emilia, VoxPopuli, etc.) are included as-is without modification, with audio standardized to 16 kHz mono Opus 64 kbps for storage efficiency. The Raon-YouTube-Commons portion is reconstructed from [YouTube-Commons](https://huggingface.co/datasets/PleIAs/YouTube-Commons) through a dedicated preprocessing pipeline (see [below](#raon-youtube-commons)). With a model-based filtering pipeline applied to Raon-OpenTTS-Pool, we derive **Raon-OpenTTS-Core**, a curated high-quality subset of **510.1K hours** and **194.5M** segments. For more details, see our paper: [Raon-OpenTTS: Open Models and Data for Robust Text-to-Speech](https://github.com/krafton-ai/RAON-OpenTTS) ## Format Each WebDataset tar shard contains pairs of files per sample: ``` {sample_key}.opus # 16 kHz mono Opus 64 kbps audio {sample_key}.json # {"text": "...", "duration": 8.42, "source": "..."} ``` > **Note:** The dataset viewer shows metadata only (sample_key, text, duration, shard_name). > Audio is stored in WebDataset tar files — see [Usage](#usage) below to download and load audio. ## Splits Each dataset config has two metadata splits: - **pool** — all samples (sample_key, text, duration, shard_name) - **core** — quality-filtered subset (**Raon-OpenTTS-Core**), retaining ~85% of the data ### Raon-OpenTTS-Core Filtering Raon-OpenTTS-Core is constructed by applying three model-based quality filters and removing the bottom 15% of samples by combined score: 1. **WER-based**: Transcribe each segment with Whisper-small ASR and compute WER against the existing text annotation. Samples with excessively high WER (> 0.35) indicate severe transcription mismatches. 2. **DNSMOS-based**: Estimate perceptual speech quality using DNSMOS. Samples below 2.24 indicate strong background noise or distortion. 3. **VAD-based**: Estimate speech activity ratio (SAR) using Silero VAD. Samples with SAR below 0.79 are dominated by silence, music, or non-speech audio. 4. **Combined**: Compute an absolute rank for each segment along each criterion (DNSMOS, WER, SAR) and average the ranks into a single combined score. Segments falling below the 15th percentile are discarded. This combined filtering achieves the best overall TTS performance across diverse evaluation benchmarks (see paper, Figure 3). ## Available Datasets | Dataset | Source | Size (h) | Avg. Dur. (s) | Segments (M) | Tars | License | DNSMOS | WER | SAR | |---|---|---|---|---|---|---|---|---|---| | **Raon-YouTube-Commons** | [YouTube-Commons](https://huggingface.co/datasets/PleIAs/YouTube-Commons) | 335k | 8.5 | 141.70 | 1,017 | CC BY 4.0 | 2.74 | 0.30 | 0.90 | | **Emilia-YODAS2** | [Emilia](https://huggingface.co/datasets/amphion/Emilia-Dataset) | 92k | 9.2 | 35.97 | 287 | CC BY-NC 4.0 | 2.82 | 0.19 | 0.90 | | **Emilia** | [Emilia](https://huggingface.co/datasets/amphion/Emilia-Dataset) | 47k | 9.3 | 18.14 | 145 | CC BY 4.0 | 3.02 | 0.18 | 0.89 | | **LibriHeavy** | [LibriHeavy](https://github.com/k2-fsa/libriheavy) | 42k | 14.2 | 10.77 | 127 | Public Domain | 3.22 | 0.11 | 0.83 | | **HiFiTTS** | [HiFiTTS2](https://www.openslr.org/hifitts/) | 37k | 10.1 | 13.09 | 109 | CC BY 4.0 | 3.20 | 0.11 | 0.84 | | **PeoplesSpeech-Dirty** | [People's Speech](https://huggingface.co/datasets/MLCommons/peoples_speech) | 28k | 14.2 | 5.48 | 63 | CC BY 4.0 | 2.63 | 0.25 | 0.86 | | **VoxPopuli** | [VoxPopuli](https://github.com/facebookresearch/voxpopuli) | 17k | 27.8 | 2.24 | 50 | CC-0 | 2.82 | 0.36 | 0.83 | | **PeoplesSpeech-Clean** | [People's Speech](https://huggingface.co/datasets/MLCommons/peoples_speech) | 10k | — | 1.50 | 18 | CC BY 4.0 | — | — | — | | **LibriTTS-R** | [LibriTTS-R](https://www.openslr.org/141/) | 552 | 5.6 | 0.35 | 2 | CC BY 4.0 | 2.96 | 0.06 | 0.91 | | **SPGISpeech2-Cut** | SPGISpeech 2.0 | 889 | 14.4 | 0.22 | 3 | Kensho UA | 2.72 | 0.08 | 0.90 | | | | | | | | | | | | | **Total** | | **615k** | **9.2** | **239.7** | **1,821** | — | 2.83 | 0.24 | 0.89 | ### Raon-YouTube-Commons A substantial portion of Raon-OpenTTS-Pool (335K hours) is derived from [YouTube-Commons](https://huggingface.co/datasets/PleIAs/YouTube-Commons). Since the original release provides only YouTube URLs with noisy or unreliable transcriptions, we reconstructed it into a high-quality speech-text dataset through the following pipeline: 1. **Audio collection**: Download audio from YouTube URLs in the original dataset 2. **Source separation** (UVR-MDX): Suppress background music and non-vocal components 3. **Speaker diarization** (PyAnnote 3.1): Estimate speaker boundaries to ensure single-speaker segments 4. **Voice activity detection** (Silero VAD): Segment continuous speech regions into clips of 3--30 seconds 5. **Automatic transcription** (Whisper-large-v3): Transcribe each segment to obtain aligned speech-text pairs 6. **Standardization**: Resample to 16 kHz mono, encode as 64 kbps Opus The resulting dataset is released as **Raon-YouTube-Commons** in this repository. ### Non-redistributable Datasets Two additional datasets used in training cannot be included due to license restrictions. Users who have agreed to the license on HuggingFace can automatically download and convert them using `prepare_nonredist_datasets.py`: | Dataset | Size (h) | License | Source | |---|---|---|---| | GigaSpeech | 10k | License agreement required | [speechcolab/gigaspeech](https://huggingface.co/datasets/speechcolab/gigaspeech) | | SPGISpeech | 5k | Non-commercial (Kensho) | [kensho/spgispeech](https://huggingface.co/datasets/kensho/spgispeech) | See [Preparing Non-redistributable Datasets](#preparing-non-redistributable-datasets) for instructions. --- ## Usage ### 1. Metadata (pool / core split) ```python from datasets import load_dataset # Core metadata for a single dataset meta = load_dataset("KRAFTON/Raon-OpenTTS-Pool", "Raon-YouTube-Commons", split="core") # Columns: sample_key, text, duration, shard_name print(meta[0]) # All datasets combined all_core = load_dataset("KRAFTON/Raon-OpenTTS-Pool", "all", split="core") ``` ### 2. Audio (WebDataset, local tars) Download tars first: ```python from huggingface_hub import snapshot_download local_dir = snapshot_download("KRAFTON/Raon-OpenTTS-Pool", repo_type="dataset", ignore_patterns=["*.parquet"]) ``` Then load with WebDataset: ```python import webdataset as wds import json, io, soundfile as sf dataset = ( wds.WebDataset(f"{local_dir}/LibriTTS-R/lr-{{000000..000001}}.tar") .to_tuple("opus", "json") ) for opus_bytes, json_bytes in dataset: meta = json.loads(json_bytes) audio, sr = sf.read(io.BytesIO(opus_bytes)) text = meta["text"] ``` ### 3. Core-only training The audio tars contain pool and core samples mixed. To train on core only, filter by sample_key: ```python import webdataset as wds from datasets import load_dataset import json, io, soundfile as sf # Step 1: load core sample keys from metadata core_keys = set( load_dataset("KRAFTON/Raon-OpenTTS-Pool", "LibriTTS-R", split="core")["sample_key"] ) # Step 2: stream tars, skip non-core samples dataset = ( wds.WebDataset(f"{local_dir}/LibriTTS-R/lr-{{000000..000001}}.tar") .select(lambda s: s["__key__"] in core_keys) .to_tuple("opus", "json") ) for opus_bytes, json_bytes in dataset: meta = json.loads(json_bytes) audio, sr = sf.read(io.BytesIO(opus_bytes)) text = meta["text"] duration = meta["duration"] ``` --- ## Preparing Non-redistributable Datasets The script `prepare_nonredist_datasets.py` automatically downloads and converts GigaSpeech and SPGISpeech into the same WebDataset tar + parquet format used by Raon-OpenTTS-Pool. ### Prerequisites 1. **Accept the dataset license** on each HuggingFace dataset page: - GigaSpeech: https://huggingface.co/datasets/speechcolab/gigaspeech - SPGISpeech: https://huggingface.co/datasets/kensho/spgispeech 2. **Set your HuggingFace token** (from an account that has accepted the licenses): ```bash export HF_TOKEN=hf_your_token_here ``` 3. **Install dependencies:** ```bash pip install "datasets<4.0" soundfile pyarrow numpy tqdm ``` > **Note:** `datasets>=4.0` dropped `soundfile` audio decoding and requires `torchcodec` > with system FFmpeg libraries. Use `datasets<4.0` (e.g. `datasets==3.5.0`) to avoid this. 4. **ffmpeg** must be in PATH. ### GigaSpeech ```bash # Download and convert xl subset from HuggingFace Hub python prepare_nonredist_datasets.py gigaspeech \ --output_dir ./GigaSpeech \ --gigaspeech_subset xl \ --num_workers 16 # Or from a local HF snapshot (no HF_TOKEN needed) python prepare_nonredist_datasets.py gigaspeech \ --source_dir /path/to/gigaspeech_local \ --output_dir ./GigaSpeech \ --gigaspeech_subset xl ``` Available subsets: `xs` (10h), `s` (250h), `m` (1000h), `l` (2500h), `xl` (10000h) ### SPGISpeech ```bash # Download and convert L subset from HuggingFace Hub python prepare_nonredist_datasets.py spgispeech \ --output_dir ./SPGISpeech \ --spgispeech_subset L \ --num_workers 16 # Or from a local HF snapshot (no HF_TOKEN needed) python prepare_nonredist_datasets.py spgispeech \ --source_dir /path/to/spgispeech_local \ --output_dir ./SPGISpeech \ --num_workers 16 ``` Available subsets: `L` (full ~5000h), `M` (~1000h), `S` (~200h), `dev`, `test` ### Output ``` / {prefix}-000000.tar # WebDataset shard (~10 GB) {prefix}-000001.tar ... metadata_pool.parquet # all samples metadata_core.parquet # = pool (no quality filtering without --core_json) ``` By default `metadata_core.parquet` equals `metadata_pool.parquet` since quality filtering requires an internal index file. If you have `pool_indices_filter_remove_15pct_combined.json` from the Raon-OpenTTS maintainers, pass it with `--core_json` to generate a filtered core split. ### Using with RAON-OpenTTS training Once prepared, pass the output directory as a `nonredist_dirs` entry in the training config: ```yaml datasets: nonredist_dirs: - /path/to/GigaSpeech - /path/to/SPGISpeech ``` --- ## License **This repository contains data from multiple sources, each with its own license.** Users must comply with the license of each individual sub-dataset they use. | Dataset | License | Commercial Use | |---|---|---| | Raon-YouTube-Commons | [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) | Yes | | Emilia | [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) | Yes | | **Emilia-YODAS2** | **[CC BY-NC 4.0](https://creativecommons.org/licenses/by-nc/4.0/)** | **No** | | LibriHeavy | Public Domain (LibriVox) | Yes | | HiFiTTS | [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) | Yes | | PeoplesSpeech-Clean / Dirty | [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) | Yes | | VoxPopuli | [CC-0](https://creativecommons.org/publicdomain/zero/1.0/) | Yes | | LibriTTS-R | [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) | Yes | | SPGISpeech2-Cut | [Kensho User Agreement](https://huggingface.co/datasets/kensho/spgispeech) | Non-commercial | | GigaSpeech (non-redist) | [License agreement required](https://huggingface.co/datasets/speechcolab/gigaspeech) | See terms | | SPGISpeech (non-redist) | [Kensho User Agreement](https://huggingface.co/datasets/kensho/spgispeech) | Non-commercial | | Metadata and dataset structure | [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) | Yes | > **Note:** Emilia-YODAS2 and SPGISpeech2-Cut are licensed under non-commercial terms. > If you require fully commercial-use data, exclude these sub-datasets via the `configs` parameter. ## Citation ```bibtex @article{raon2026opentts, title = {Raon-OpenTTS: Open Models and Data for Robust Text-to-Speech}, author = {TBD}, year = {2026}, url = {https://github.com/krafton-ai/Raon-OpenTTS} } ``` © 2026 KRAFTON