docs/inference/inference_doc.md

Inference Arguments

The following table describes the command-line arguments available for the infer-cli.py script, which is used for text-to-speech (TTS) inference with advanced batch processing capabilities. These arguments allow users to override settings defined in the configuration file (basic.toml by default).

Argument	Description	Type	Default Value	Notes
-c, --config	Path to the configuration file.	str	f5_tts/infer/examples/basic/basic.toml	Specifies the TOML configuration file to use.
-m, --model	Model name to use for inference.	str	F5TTS_v1_Base (from config)	Options: F5TTS_v1_Base, F5TTS_Base, E2TTS_Base, etc.
-mc, --model_cfg	Path to the model's YAML configuration file.	str	configs/<model>.yaml (from config)	Defines model-specific settings.
-p, --ckpt_file	Path to the model checkpoint file (.pt).	str	(from config)	Leave blank to use default checkpoint.
-v, --vocab_file	Path to the vocabulary file (.txt).	str	(from config)	Leave blank to use default vocabulary.
-r, --ref_audio	Path to the reference audio file.	str	infer/examples/basic/basic_ref_en.wav (from config)	Used as a reference for voice synthesis.
-s, --ref_text	Transcript or subtitle for the reference audio.	str	Some call me nature, others call me mother nature. (from config)	Text corresponding to the reference audio.
-t, --gen_text	Text to synthesize into speech.	str	Here we generate something just for test. (from config)	Ignored if --gen_file is provided.
-f, --gen_file	Path to a file containing text to synthesize.	str	(from config)	Overrides --gen_text if specified.
-o, --output_dir	Path to the output directory.	str	tests (from config)	Directory where generated audio files are saved.
-w, --output_file	Name of the output audio file.	str	infer_cli_<timestamp>.wav (from config)	Timestamp format: %Y%m%d_%H%M%S.
--save_chunk	Save individual audio chunks during inference.	bool	False (from config)	If enabled, saves chunks to <output_dir>/<output_file>_chunks/.
--no_legacy_text	Disable lossy ASCII transliteration for Unicode text in file names.	bool	False (from config)	If disabled, uses Unicode in file names; warns if used with --save_chunk.
--remove_silence	Remove long silences from the generated audio.	bool	False (from config)	Applies silence removal post-processing.
--load_vocoder_from_local	Load vocoder from a local directory.	bool	False (from config)	Uses ../checkpoints/vocos-mel-24khz or similar if enabled.
--vocoder_name	Name of the vocoder to use.	str	(from config, defaults to mel_spec_type)	Options: vocos, bigvgan.
--target_rms	Target loudness normalization value for output speech.	float	(from config, defaults to target_rms)	Adjusts audio loudness.
--cross_fade_duration	Duration of cross-fade between audio segments (seconds).	float	(from config, defaults to cross_fade_duration)	Smooths transitions between segments.
--nfe_step	Number of function evaluation (denoising) steps.	int	(from config, defaults to nfe_step)	Controls inference quality.
--cfg_strength	Classifier-free guidance strength.	float	(from config, defaults to cfg_strength)	Influences generation quality.
--sway_sampling_coef	Sway sampling coefficient.	float	(from config, defaults to sway_sampling_coef)	Affects sampling behavior.
--speed	Speed of the generated audio.	float	(from config, defaults to speed)	Adjusts playback speed.
--fix_duration	Fixed total duration for reference and generated audio (seconds).	float	(from config, defaults to fix_duration)	Enforces a specific duration.
--device	Device to run inference on.	str	(from config, defaults to device)	E.g., cpu, cuda.

Notes

• Arguments without default values in the script (e.g., --model, --ref_audio) inherit defaults from the configuration file.
• The --no_legacy_text flag is implemented as store_false, so enabling it sets use_legacy_text to False.
• If --gen_file is provided, it overrides --gen_text.
• The script supports multiple voices defined in the config file under the voices key, with a fallback to a main voice.
• The output audio is saved as a WAV file, and optional chunked audio segments can be saved if --save_chunk is enabled.
• The script uses cached_path for downloading model checkpoints from Hugging Face if no local checkpoint is specified.