Dolphin Small · OpenASR

Multilingual speech recognition across 40 languages -- a WeNet/ESPnet E-Branchformer (CTC + attention) covering South/Southeast/Central Asian and Chinese-dialect speech

Native speech-to-text in the OpenASR runtime — engineered for peak performance on CPU & GPU, no Python at inference time.

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✨ Highlights

• 🌏 40 languages, one checkpoint — a WeNet/ESPnet E-Branchformer spanning South Asian (Hindi, Bengali, Urdu...), Southeast Asian (Vietnamese, Thai, Indonesian...), Central Asian/Turkic (Kazakh, Uzbek, Azerbaijani...), and Chinese/Cantonese speech, with per-utterance <lang><region> prompting
• 🧩 Joint CTC + attention — an E-Branchformer encoder with a Transformer decoder and CTC/attention rescoring, verified against a shape-derived runtime contract shared with the rest of the Dolphin family
• 🐬 SentencePiece BPE vocab — a shared subword vocabulary across all 40 languages (distinct from the cn-dialect family's fixed character vocab), suited to code-mixed and cross-lingual speech
• 🪶 372M parameters, small tier — the larger of the two multilingual Dolphin sizes (paired with the more compact dolphin-base)
• 🦀 Native in OpenASR — .oasr packs run with no Python at inference, engineered for peak performance on CPU & GPU

🚀 Quickstart

# 1. Install the OpenASR CLI  ·  https://openasr.org
# 2. Pull a build (pick a quant — see the table below)
openasr pull dolphin-small:q8

# 3. Transcribe
openasr transcribe audio.wav --model dolphin-small

All builds for this model:

openasr pull dolphin-small:fp16
openasr pull dolphin-small:q8
openasr pull dolphin-small:q4

📦 Available builds

_{RTF = real-time factor on the shared 11s JFK clip (out-of-distribution, drift signal only) plus an in-language Mandarin sanity clip (lower is faster); RAM peak measured per pack in an isolated subprocess. ΔCER compares each quantized build's JFK + zh sanity clip transcript to this model's fp16 JFK + zh sanity clip transcript, so it measures quantization drift rather than absolute recognition accuracy. q8_0 is the recommended default — near-reference quality at a fraction of the footprint.}

🧠 About Dolphin Small

Dolphin Small is the 372M "small" tier of DataoceanAI's multilingual Dolphin speech- recognition line, built on the Dolphin / ESPnet recipe as an E-Branchformer encoder + Transformer decoder trained with a joint CTC + attention objective over a shared SentencePiece BPE vocabulary. Unlike the dedicated dolphin-cn-dialect-* checkpoints (fixed <zh> language token, Chinese-only char vocab), this multilingual checkpoint varies both the language and region prompt slots across the card's advertised 40 languages -- South Asian, Southeast Asian, Central Asian/Turkic, and Chinese (including Cantonese, listed separately as yue) -- while collapsing this product's own Chinese-dialect granularity into a single zh (the dedicated dolphin-cn-dialect-small/-base packs cover per-dialect prompting; this checkpoint does not). This OpenASR repo repackages the weights as .oasr packs that run natively in the OpenASR runtime -- no Python at inference, all decoding local. It ships in fp16 (maximum fidelity), q8_0 (recommended), and q4_k builds.

Note: this model does not emit punctuation. Its upstream training corpus is transcribed without punctuation marks, so the decoder never predicts a punctuation token -- there is no setting to enable it. Transcripts are plain, unpunctuated text by design.

Verification: local testing covers Mandarin (zh), sanity-checked against the upstream architecture and confirmed bit-stable across fp16/q8_0/q4_k quants.

⚙️ How these packs were made

Converted from DataoceanAI/dolphin-small with the OpenASR importer:

openasr model-pack import dolphin <src> <out>.oasr \
  --package-id dolphin-small --quantization {fp16,q8-0,q4-k}

The .oasr container is GGUF-backed; packs use zero-copy mmap weight binding and graph buffer reuse to keep peak memory low.

⚖️ License

These packs inherit the upstream model's license: Apache-2.0 (source). OpenASR packaging retains the upstream copyright and NOTICE; the only modifications are format conversion and quantization.

🙏 Acknowledgements

This pack is a redistribution of Dolphin Small, created and open-sourced by DataoceanAI (DataoceanAI/dolphin-small). All credit for the original architecture, training, and weights belongs to the authors; the license is inherited from and identical to the upstream model (Apache-2.0). The model builds on the Dolphin multilingual ASR project and the ESPnet E-Branchformer / joint CTC-attention recipe -- thank you to the Dolphin and ESPnet teams and to DataoceanAI for releasing their work openly. OpenASR only performs format conversion, quantization, runtime verification, and local-inference adaptation.

🔗 Links

• 🦀 OpenASR — https://github.com/QuintinShaw/openasr
• 🌐 Website — https://openasr.org
• 🤗 Upstream model — DataoceanAI/dolphin-small