Fun-ASR-Nano

audio.cpp runs Fun-ASR-Nano-2512 as a native offline ASR model on CPU and CUDA. The runtime accepts the official Hugging Face safetensors checkpoint and standalone F16 or Q8_0 GGUF files.

Field	Value
Family	fun_asr_nano
Task	asr
Mode	offline
Languages	auto, zh, en, ja
Audio	WAV; converted to mono 16 kHz internally
Output	Transcript text
Streaming	Not exposed
Timestamps	Not exposed

Install

The model-spec manager installs the Q8_0 standalone GGUF by default:

python3 tools/model_manager_v2.py install fun_asr_nano

Select another published format explicitly:

python3 tools/model_manager_v2.py install fun_asr_nano_2512_f16
python3 tools/model_manager_v2.py install fun_asr_nano_2512_safetensors

Published GGUF files and their SHA256 manifest are available at FunAudioLLM/Fun-ASR-Nano-2512-GGUF. The package catalog pins an immutable Hub revision.

CLI

audiocpp_cli \
  --task asr \
  --family fun_asr_nano \
  --model models/Fun-ASR-Nano-2512-GGUF/fun-asr-nano-2512-q8_0.gguf \
  --backend cuda \
  --audio speech.wav \
  --text-out transcript.txt

The same command accepts the F16 GGUF file or the official safetensors model directory.

Request Options

Option	Values	Default	Meaning
language	auto, zh, en, ja	auto	Recognition language hint.
enable_itn	true, false	true	Enable inverse text normalization in the prompt.
max_tokens	positive integer	512	Maximum transcript tokens generated per chunk.
audio_chunk_mode	auto, fixed, none	auto	Offline audio chunking policy.
audio_chunk_seconds	positive seconds	30	Chunk duration for fixed/automatic chunking.

For example:

audiocpp_cli --task asr --family fun_asr_nano \
  --model models/Fun-ASR-Nano-2512-GGUF/fun-asr-nano-2512-q8_0.gguf \
  --backend cuda --audio meeting.wav \
  --language zh \
  --request-option enable_itn=true \
  --audio-chunk-mode fixed \
  --audio-chunk-seconds 30

Weight Storage

fun_asr_nano.weight_type sets a shared storage preference. Component overrides are fun_asr_nano.encoder_weight_type, fun_asr_nano.adaptor_weight_type, and fun_asr_nano.decoder_weight_type. Supported values are native, f32, f16, bf16, and q8_0.

On CUDA, native, F16, and Q8 shared preferences are promoted to BF16 for the decoder to keep logits stable. Encoder and adaptor weights retain the shared type, so a Q8_0 GGUF keeps those large matrix paths quantized. An explicit fun_asr_nano.decoder_weight_type forces that component's storage type. CPU uses the requested or native stored types without promotion.

Server

server.json:

{
  "host": "127.0.0.1",
  "port": 8080,
  "backend": "cuda",
  "device": 0,
  "threads": 4,
  "lazy_load": true,
  "models": [
    {
      "id": "fun-asr-nano",
      "family": "fun_asr_nano",
      "path": "models/Fun-ASR-Nano-2512-GGUF/fun-asr-nano-2512-q8_0.gguf",
      "task": "asr",
      "mode": "offline"
    }
  ]
}

audiocpp_server --config server.json

curl http://127.0.0.1:8080/v1/audio/transcriptions \
  -F model=fun-asr-nano \
  -F language=auto \
  -F file=@speech.wav

The endpoint follows the OpenAI multipart transcription shape and returns {"text":"...","timing":{...}}.

GGUF Conversion

audiocpp_gguf \
  --input /path/to/Fun-ASR-Nano-2512-hf/model.safetensors \
  --root /path/to/Fun-ASR-Nano-2512-hf \
  --output fun-asr-nano-2512-q8_0.gguf \
  --type q8_0 \
  --family fun_asr_nano \
  --model-spec model_specs/fun_asr_nano.json

The standalone output embeds the config, processor config, tokenizer, chat template, and model package specification. Inspect it with:

audiocpp_gguf --inspect fun-asr-nano-2512-q8_0.gguf

Validation

The published F16 and Q8_0 files were checked with the same 14.07-second reference WAV on CPU and NVIDIA H100 CUDA. CLI and OpenAI-compatible server transcripts matched the official safetensors path. The Q8_0 server validation completed at approximately 0.0725 RTF on H100.

License

The checkpoint and converted weights are governed by the FunASR Model Open Source License Agreement v1.1 distributed with the official model. Review that agreement before use or redistribution.