Add dataset card (v4: 486k train + 9.9k val, 17 sources)

README.md

@@ -1,4 +1,17 @@
 ---
+language:
+- km
+license: other
+task_categories:
+- automatic-speech-recognition
+pretty_name: Khmer ASR v4 (actableai)
+size_categories:
+- 100K<n<1M
+tags:
+- khmer
+- asr
+- speech
+- audio
 dataset_info:
   features:
   - name: audio
@@ -28,3 +41,77 @@ configs:
   - split: validation
     path: data/validation-*
 ---
+
+# Khmer ASR Dataset (v4)
+
+A consolidated Khmer (ខ្មែរ) speech corpus used to train the actableai Khmer ASR
+model (NeMo, v4 checkpoint). Combines 17 sub-corpora spanning call-center
+recordings, broadcast/cultural content, public ASR corpora, and TTS-synthesised
+speech.
+
+## Summary
+
+| Split      | Utterances | Hours   |
+|------------|-----------:|--------:|
+| train      |    486,046 |  502.77 |
+| validation |      9,910 |   10.20 |
+| **total**  |  **495,956** | **512.97** |
+
+- Sampling rate: 16 kHz, mono, PCM_16.
+- Text: Khmer script (light normalization from the training pipeline only).
+
+## Schema
+
+| Field     | Type              | Description                                |
+|-----------|-------------------|--------------------------------------------|
+| audio     | `Audio(16000 Hz)` | Mono waveform embedded in parquet.         |
+| text      | `string`          | Khmer transcript.                          |
+| duration  | `float32`         | Seconds.                                   |
+| source    | `string`          | Sub-corpus tag (see below).                |
+
+## Composition by source
+
+| Source               | Train     | Validation |
+|----------------------|----------:|-----------:|
+| metfone_v1_v3        |   173,836 |      3,547 |
+| synth_full           |   107,488 |      2,193 |
+| ddd_cultural         |    55,570 |      1,134 |
+| sethisak_en_kh       |    26,698 |        544 |
+| sethisak_kh_en_v2    |    26,698 |        544 |
+| rinabuoy_train       |    24,833 |        506 |
+| sethisak             |    21,798 |        444 |
+| djsamseng_large      |    17,628 |        359 |
+| km_corpus            |    14,645 |        298 |
+| sethisak_asr         |     5,545 |        113 |
+| openslr42            |     2,848 |         58 |
+| kheng                |     2,771 |         56 |
+| mpwt                 |     2,017 |         41 |
+| shunya               |     1,630 |         33 |
+| moses                |       949 |         19 |
+| rinabuoy_test        |       750 |         15 |
+| grkpp                |       342 |          6 |
+
+`synth_full` is TTS-synthesised speech produced by the actableai OmniVoice
+pipeline — added in v4 to widen phonetic and prosodic coverage.
+
+## Usage
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset("actableai/data-khmer", split="train", streaming=True)
+example = next(iter(ds))
+print(example["text"], example["duration"], example["source"])
+print(example["audio"]["sampling_rate"], example["audio"]["array"].shape)
+```
+
+For ASR evaluation, note that Khmer is a syllabic script without reliable
+word boundaries — prefer **CER** over WER.
+
+## Provenance & licensing
+
+This is a research aggregation of multiple upstream sources. The licensing of
+each sub-corpus follows its upstream project; downstream users are responsible
+for verifying compliance with each source's terms before commercial use.
+Synthesised audio (`synth_full`) is released under the same terms as the
+upstream TTS voices it was produced from.