LongCat-AudioDiT - Meituan's open-source text-to-speech model
LongCat-AudioDiT is a high-fidelity diffusion-based text-to-speech (TTS) model open-sourced by Meituan. Its core innovation lies in directly generating the text through diffusion in the waveform latent space, rather than using intermediate representations like Mel-frequency spectra, effectively avoiding error accumulation...
What is LongCat-AudioDiT?
LongCat-AudioDiT is a high-fidelity diffusion-based text-to-speech (TTS) model open-sourced by Meituan. Its core innovation lies in direct diffusion generation within the waveform latent space, rather than traditional intermediate representations like Mel-spectrum, effectively avoiding error accumulation and significantly simplifying the process. The model introduces Adaptive Projection Guidance (APG) to replace traditional CFG, correcting the training-inference mismatch problem. In the Seed benchmark, version 3.5B surpasses the previous state-of-the-art (Seed-TTS 0.809) with a Chinese similarity of 0.818, achieving top-tier zero-shot speech cloning performance. The model is open-source under the MIT license, providing both 1B and 3.5B versions and complete inference tools.
Main functions of LongCat-AudioDiT
- Text-to-speechConverts any text into 24kHz high-fidelity natural speech, supporting multi-language synthesis including Chinese and English.
- Zero-sample speech cloningWith just 3-10 seconds of reference audio, you can accurately replicate the voice of any speaker without any special training.
- Waveform latent space generationThe model diffuses directly in the waveform latent space, avoiding information loss in traditional Mel spectrum and simplifying the pipeline.
- Adaptive projection guidanceThe model uses APG technology to replace traditional CFG, correcting the training-inference mismatch and improving generation quality.
- Flexible Inference InterfaceIt provides both CLI command line and Python API modes, supporting single-line synthesis and batch processing.
- Dual-specification modelThe open-source 1B lightweight version and the 3.5B high-quality version meet the speed and quality requirements of different scenarios.
How to use LongCat-AudioDiT
- Environmental preparation: Clone repository execution
pip install -r requirements.txtInstall dependencies. - Loading Model:pass
AudioDiTModel.from_pretrained("meituan-longcat/LongCat-AudioDiT-1B")Load the pre-trained model onto the GPU. - Prepare textUse AutoTokenizer to encode the target text into the model input format.
- Setting parameters: Specifies the generation duration, diffusion steps, guidance method (CFG or APG), and intensity.
- Execution reasoning: Call the model to generate audio, TTS directly input text, clone requires additional reference audio and prompt text.
- Save resultsUse soundfile to write the generated waveform data to a WAV file to complete the output.
Key information and usage requirements for LongCat-AudioDiT
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DeveloperMeituan
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technical routeDiffusion model + direct generation of waveform latent space
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Model size: 1B (Lightweight Edition), 3.5B (Flagship Edition)
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Audio quality24kHz sampling rate
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Core InnovationWaveform latent space diffusion, adaptive projection guidance (APG)
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performance levelSeed benchmark, state-of-the-art (SOTA), Chinese similarity 0.818
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hardwareNVIDIA GPU (CUDA supported), ≥8GB VRAM recommended.
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software:Python 3.8+, PyTorch, transformers, librosa
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Dependency installation:implement
pip install -r requirements.txt
LongCat-AudioDiT's core advantages
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End-to-end simplificationIt generates directly in the waveform latent space, without the need for intermediate representations such as Mel spectrum, avoiding error accumulation and making the process simpler.
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SOTA Voice CloningSeed achieves a benchmark Chinese similarity of 0.818, surpassing the previous state-of-the-art model Seed-TTS, and its zero-sample cloning performance is top-notch.
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Inference quality optimizationIt supports Adaptive Projection Guidance (APG) to replace traditional CFG, correcting training-inference mismatch and generating more stable and natural results.
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Flexible dual versionOffers a fast and lightweight 1B version and an ultra-high-quality 3.5B version, adaptable to different scenario needs.
LongCat-AudioDiT project address
- GitHub repositoryhttps://github.com/meituan-longcat/LongCat-AudioDiT
- HuggingFace model library:
- https://huggingface.co/meituan-longcat/LongCat-AudioDiT-1B
- https://huggingface.co/meituan-longcat/LongCat-AudioDiT-3.5B
Comparison of LongCat-AudioDiT with similar products
| Model | Developer | technical route | Open source situation | Core features |
|---|---|---|---|---|
| LongCat-AudioDiT | Meituan | Diffusion model + waveform latent space | Completely open source (MIT) | Seed benchmark SOTA, APG bootstrapping, end-to-end generation |
| Seed-TTS | ByteDance | diffusion model | Closed source | Former SOTA, high-quality voice cloning |
| CosyVoice | Ali Tongyi | Flow Matching | open source | Supports command control and cross-language synthesis |
Application scenarios of LongCat-AudioDiT
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Audio content productionThe model can quickly generate audiobooks, podcasts, news broadcasts, and other content, and supports multi-character voice cloning to reduce production costs.
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Intelligent Customer Service SystemCustomize brand-specific voices for businesses to achieve natural and fluent voice interaction services and enhance user experience.
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Game and animation voice actingBy replicating character voices with zero samples, the dubbing costs for multilingual localization of games and animations are significantly reduced.
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Virtual Human Live StreamingIt provides digital humans with high-fidelity real-time voice-driven capabilities, significantly enhancing the immersion and realism of virtual live streaming.
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Accessibility toolsIt can read text aloud to visually impaired users or help aphasic individuals reconstruct their own unique voice through a small amount of recording.