| --- |
| language: |
| - sa |
| license: apache-2.0 |
| pipeline_tag: text-to-speech |
| base_model: ai4bharat/IndicF5 |
| tags: |
| - sanskrit |
| - chant |
| - text-to-speech |
| - f5-tts |
| - indicf5 |
| - bigvgan |
| --- |
| |
| # Vāgdhenu — Sanskrit Chant TTS (weights) |
|
|
| Model weights for [**Vāgdhenu**](https://github.com/prathoshap/vagdhenu), a single-speaker Sanskrit **chant (pārāyaṇa) TTS**. MOS ~4.6 (expert listener); conjuncts including retroflex aspirates render 100% correctly. |
|
|
| ## Files |
| | file | what | |
| |---|---| |
| | `voice_steer_ema_2026-06-17.pt` | **Production voice** — voice-steered, more reference-responsive (the recommended default). | |
| | `voice_armA_ema_2026-06-11.pt` | Fallback — reference-driven chant (voice + swara + pace from the reference clip). | |
| | `voc_bigvgan_EMA_2026-06-11.pth` | **Vocoder** — NVIDIA BigVGAN-v2 fine-tuned on F5 vocos-mel (mandatory; vocos shivers on long vowels). | |
|
|
| The base DiT + `vocab.txt` come from [`ai4bharat/IndicF5`](https://huggingface.co/ai4bharat/IndicF5) (auto-downloaded by the repo's setup). |
|
|
| ## Architecture |
| IndicF5 / F5-TTS — flow-matching **DiT** (OT-CFM mel-infilling, dim 1024 / depth 22 / heads 16, ~337M params, **no native duration or pitch head**) → BigVGAN-v2 vocoder. Sanskrit is routed through **Kannada script** (Devanagari triggers Hindi schwa-deletion). |
|
|
| ## Usage |
| See the [GitHub repo](https://github.com/prathoshap/vagdhenu) — `bash scripts/setup.sh` downloads these weights to `models/`, then `python src/render.py ...` renders a Devanagari verse + meter to a chanted wav. |
|
|
| **The key lever is the reference** (F5 prosody is text-driven, not designable): supply the prosody you want as a clean, exactly-matched reference clip (the *half-reference rule* — `ref_text` must match the reference audio's spoken span on a word/daṇḍa boundary). A per-meter reference bank ships with the repo. |
|
|
| ## Training |
| Fine-tuned from IndicF5 on a ~5 h single-speaker Sanskrit chant corpus ([`prathoshap/vagdhenu-data`](https://huggingface.co/datasets/prathoshap/vagdhenu-data)); the production voice adds a voice-steering retrain on paired clips. Full method in the repo's `docs/TECH_REPORT.md`. |
|
|
| ## Intended use & limitations |
| Synthesis of classical Sanskrit chant (pārāyaṇa) for recitation, study, and accessibility. **No Vedic svaras.** Prosody is **reference-driven**, not arbitrarily designable. The voice is the author's own — please use responsibly and do not impersonate. |
|
|
| ## License & attribution |
| Our contribution under **Apache-2.0**. Built on **AI4Bharat IndicF5** (MIT), **NVIDIA BigVGAN-v2**, and **F5-TTS** — the vocoder is a BigVGAN-v2 derivative; please observe NVIDIA's BigVGAN license terms. Cite *Vāgdhenu* (BibTeX with the technical report). |
|
|
