[Help] [Metis] Voice Conversion Irreproducible

Problem Overview

The example code in models/tts/metis/metis_infer_vc.py is incorrect and cannot be run as-is. Specifically:

• It loads ft.json via load_config, which is unrelated to voice conversion.
• It attempts to load metis_vc.safetensors, which does not exist in the HuggingFace repo. Only the following two files are available:
  • metis_vc_lora_16.safetensors
  • metis_vc_lora_16_adapter.safetensors

Steps Taken

1. Referred to the example usage for TTS here: https://github.com/open-mmlab/Amphion/tree/main/models/tts/metis#2-example-usaage

2. Modified the code to a voice conversion (VC) version, as follows:

   device = "cuda:0"
   metis_cfg = load_config("./models/tts/metis/config/vc.json")
   
   base_ckpt_dir = snapshot_download(
       "amphion/metis",
       repo_type="model",
       local_dir="./models/tts/metis/ckpt",
       allow_patterns=["metis_base/model.safetensors"],
   )
   lora_ckpt_dir = snapshot_download(
       "amphion/metis",
       repo_type="model",
       local_dir="./models/tts/metis/ckpt",
       allow_patterns=["metis_vc/metis_vc_lora_16.safetensors"],
   )
   adapter_ckpt_dir = snapshot_download(
       "amphion/metis",
       repo_type="model",
       local_dir="./models/tts/metis/ckpt",
       allow_patterns=["metis_vc/metis_vc_lora_16_adapter.safetensors"],
   )
   
   base_ckpt_path = os.path.join(base_ckpt_dir, "metis_base/model.safetensors")
   lora_ckpt_path = os.path.join(lora_ckpt_dir, "metis_vc/metis_vc_lora_16.safetensors")
   adapter_ckpt_path = os.path.join(adapter_ckpt_dir, "metis_vc/metis_vc_lora_16_adapter.safetensors")
   
   metis = Metis(
       base_ckpt_path=base_ckpt_path,
       lora_ckpt_path=lora_ckpt_path,
       adapter_ckpt_path=adapter_ckpt_path,
       cfg=metis_cfg,
       device=device,
       model_type="vc",
   )
   
   prompt_speech_path = "./models/tts/metis/wav/vc/prompt.wav"
   source_speech_path = "./models/tts/metis/wav/vc/source.wav"
   
   n_timesteps = 20
   cfg = 1.0
   
   gen_speech = metis(
       prompt_speech_path=prompt_speech_path,
       source_speech_path=source_speech_path,
       cfg=cfg,
       n_timesteps=n_timesteps,
       model_type="vc",
   )
   
   sf.write("./models/tts/metis/wav/vc/gen.wav", gen_speech, 24000)

3. Used the example WAV files in models/tts/metis/wav/vc/.

Expected Outcome

Expected to generate intelligible and high-quality converted speech, similar to the samples on the demo page.

Actual Outcome

The generated audio is very low quality and does not contain any human voice — it's mostly noise. This makes the current VC pipeline irreproducible.

Environment Information

• Operating System: Ubuntu 20.04.5 LTS
• Python Version: 3.10.16
• Driver & CUDA Version: Driver 470.103.01 & CUDA 11.4
• Error Messages and Logs: No runtime errors, but the model output is unusable.

Additional Context

Please provide the correct inference code used to generate the demo samples at https://metis-demo.github.io/#metis-vc. It would be especially helpful if you could:

• Fix the example script at metis_infer_vc.py
• Clearly specify which checkpoint files are required
• Share the hyperparameters (cfg, n_timesteps, etc.) and audio preprocessing steps used in your demos

Thanks for your work. I am more than excited to use Metis VC once this is resolved.