Experimental Gradio Space demo for VoxCPM2 powered by nanovllm-voxcpm.

This repo keeps the existing Gradio frontend layout and swaps only the backend inference path to Nano-vLLM.

Notes:

• This is the non-Docker experiment path. It relies on a persistent GPU Gradio Space.
• flash-attn and nanovllm-voxcpm are pinned in requirements.txt, so they install during Space build instead of on first request.
• ZipEnhancer denoising is supported for reference audio cloning. The default denoiser model is iic/speech_zipenhancer_ans_multiloss_16k_base.
• The Space now defaults to a hardened runtime path:
  • If /data exists, request logs are written to daily JSONL files like /data/logs/2026-04-05.jsonl.
  • Model, pip, and temporary caches now stay on the default runtime paths instead of consuming persistent storage.
  • Backend prewarm is enabled by default, so startup can begin dependency install + model load in the background.
  • Gradio SSR is disabled by default for stability.
• The first cold start may still spend extra time installing dependencies, downloading the model, and loading the server.
• SenseVoiceSmall is downloaded from Hugging Face and cached locally before ASR initialization.
• ASR_DEVICE defaults to cpu to avoid competing with TTS GPU memory.
• Reference audio longer than 50 seconds is rejected early before denoising or Nano-vLLM encoding.
• The LocDiT flow-matching steps slider is wired to Nano-vLLM server inference_timesteps; changing it rebuilds the backend server.
• The existing normalize toggle is kept for UI compatibility, but Nano-vLLM currently ignores it.
• The existing denoise toggle now runs ZipEnhancer on the reference audio before encoding it to latents.
• packages.txt is required because this path needs extra system build dependencies.

Stability recommendation:

• Use a persistent GPU Space.
• Attach persistent storage so /data is available.
• Keep the default queue concurrency at 1 unless you have profiled GPU memory headroom.

Recommended environment variables:

• HF_REPO_ID: Hugging Face model repo id. Defaults to openbmb/VoxCPM2
• HF_TOKEN: required if the model repo is private
• NANOVLLM_MODEL: optional direct model ref override. Can be a local path or HF repo id
• NANOVLLM_MODEL_PATH: optional local model path override
• ASR_DEVICE: defaults to cpu
• ZIPENHANCER_MODEL_ID: optional ModelScope denoiser model id or local path. Defaults to iic/speech_zipenhancer_ans_multiloss_16k_base
• NANOVLLM_INFERENCE_TIMESTEPS: initial default is 10
• NANOVLLM_PREWARM: defaults to true
• NANOVLLM_SERVERPOOL_MAX_NUM_BATCHED_TOKENS: defaults to 8192
• NANOVLLM_SERVERPOOL_MAX_NUM_SEQS: defaults to 16
• NANOVLLM_SERVERPOOL_MAX_MODEL_LEN: defaults to 4096
• NANOVLLM_SERVERPOOL_GPU_MEMORY_UTILIZATION: defaults to 0.95
• NANOVLLM_SERVERPOOL_ENFORCE_EAGER: defaults to false
• NANOVLLM_SERVERPOOL_DEVICES: defaults to 0
• NANOVLLM_MAX_GENERATE_LENGTH: defaults to 2000
• NANOVLLM_TEMPERATURE: defaults to 1.0
• REQUEST_LOG_DIR: optional persistent request log directory. Defaults to /data/logs when /data exists
• GRADIO_QUEUE_MAX_SIZE: defaults to 30
• GRADIO_DEFAULT_CONCURRENCY_LIMIT: defaults to 6 (uses async server pool bridge for thread-safe concurrency)
• NANOVLLM_API_CONNECT_TIMEOUT: defaults to 5
• NANOVLLM_API_ASR_TIMEOUT: defaults to 30
• NANOVLLM_API_DENOISE_TIMEOUT: defaults to 60
• NANOVLLM_API_GENERATE_TIMEOUT: defaults to 120
• DENOISE_MAX_CONCURRENT: defaults to 1 (limits concurrent ZipEnhancer denoise requests to avoid GPU OOM)
• GRADIO_SSR_MODE: defaults to false