IMS Toucan is a toolkit for teaching, training and using state-of-the-art Speech Synthesis models, developed at the Institute for Natural Language Processing (IMS), University of Stuttgart, Germany. Everything is pure Python and PyTorch based to keep it as simple and beginner-friendly, yet powerful as possible.

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Demonstration 🦚

Pre-Generated Audios

Multi-lingual and multi-speaker audios

Cloning prosody across speakers

Human-in-the-loop edited poetry for German literary studies

Interactive Demos

Check out our multi-lingual demo on Huggingface🤗

Check out our demo on exact style cloning on Huggingface🤗

Check out our human-in-the-loop poetry reading demo on Huggingface🤗

You can also design the voice of a speaker who doesn't exist on Huggingface🤗

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New Features 🐣

2021

• We officially introduced IMS Toucan in our contribution to the Blizzard Challenge 2021.
• As shown in this paper vocoders can be used to perform super-resolution and spectrogram inversion simultaneously. We added this to our HiFi-GAN vocoder. It now takes 16kHz spectrograms as input, but produces 48kHz waveforms.
• We now use articulatory representations of phonemes as the input for all models. This allows us to easily use multilingual data to benefit less resource-rich languages.
• We provide a checkpoint trained with a variant of model agnostic meta learning from which you can fine-tune a model with very little data in almost any language. The last two contributions are described in our paper that we presented at the ACL 2022!
• We now use a small self-contained Aligner that is trained with CTC and an auxiliary spectrogram reconstruction objective, inspired by this implementation for a variety of applications.

2022

• We reworked our input representation to now include tone, lengthening and primary stress. All phonemes in the IPA standard are now supported, so you can train on any language, as long as you have a way to convert text to IPA. We also include word-boundary pseudo-tokens which are only visible to the text encoder.
• By conditioning the TTS on speaker and language embeddings in a specific way, multi-lingual and multi-speaker models are possible. You can use any speaker in any language, regardless of the language that the speakers themselves are speaking. We will present a paper on this at AACL 2022!
• Exactly cloning the prosody of a reference utterance is now also possible, and it works in conjunction with everything else! So any utterance in any language spoken by any speaker can be replicated and controlled. We will present a paper on this at SLT 2022. We apply this to literary studies on poetry and presented a paper on this at Interspeech 2022!
• We added simple and intuitive parameters to scale the variance of pitch and energy in synthesized speech.
• We added a scorer utility to inspect your data and find potentially problematic samples.
• You can now use weights & biases to keep track of your training runs, if you want.
• We upgraded our vocoder from HiFiGAN to the recently published Avocodo.
• We now use a self-supervised embedding function based on GST, but with a special training procedure to allow for very rich speaker conditioning.
• We trained a GAN to sample from this new embeddingspace. This allows us to speak in voices of speakers that do not exist. We also found a way to make the sampling process very controllable using intuitive sliders. Check out our newest demo on Huggingface to try it yourself!

Pretrained models are available!

Pretrained checkpoints for our massively multi-lingual model, the self-contained aligner, the embedding function, the vocoder and the embedding GAN are available in the release section. Run the run_model_downloader.py script to automatically download them from the release page and put them into their appropriate locations with appropriate names.

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Installation 🦉

Basic Requirements

To install this toolkit, clone it onto the machine you want to use it on (should have at least one GPU if you intend to train models on that machine. For inference, you can get by without GPU). Navigate to the directory you have cloned. We recommend creating and activating a conda virtual environment to install the basic requirements into. After creating the environment, the command you need to use to activate the virtual environment is displayed. The commands below show everything you need to do. If you don't have a GPU, remove the cuda part from the torch installation line.

conda create --prefix ./toucan_conda_venv --no-default-packages python=3.8

pip install --no-cache-dir -r requirements.txt

pip install torch==1.10.1+cu111 torchvision==0.11.2+cu111 torchaudio==0.10.1 -f https://download.pytorch.org/whl/torch_stable.html

espeak-ng

And finally you need to have espeak-ng installed on your system, because it is used as backend for the phonemizer. If you replace the phonemizer, you don't need it. On most Linux environments it will be installed already, and if it is not, and you have the sufficient rights, you can install it by simply running

apt-get install espeak-ng

For other systems, e.g. Windows, they provide a convenient .msi installer file on their GitHub release page. After installation on non-linux systems, you'll also need to tell the phonemizer library where to find your espeak installation, which is discussed in this issue. Since the project is still in active development, there are frequent updates, which can actually benefit your use significantly.

Pretrained Models

You don't need to use pretrained models, but it can speed things up tremendously. Run the run_model_downloader.py script to automatically download them from the release page and put them into their appropriate locations with appropriate names.

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Creating a new Pipeline 🦆

To create a new pipeline to train an Avocodo vocoder, you only need a set of audio files. To create a new pipeline for a FastSpeech 2, you need audio files, corresponding text labels, and an already trained Aligner model to estimate the duration information that FastSpeech 2 needs as input.

Build an Avocodo Pipeline

This should not be necessary, because we provide a pretrained model and one of the key benefits of vocoders in general is how incredibly speaker independent they are. But in case you want to train your own anyway, here are the instructions: In the directory called You will need a function to return the list of all the absolute paths to each of the audio files in your dataset as strings. If you already have a path_to_transcript_dict of your data for FastSpeech 2 training, you can simply take the keys of the dict and transform them into a list.

Then go to the directory TrainingInterfaces/TrainingPipelines. In there, make a copy of any existing pipeline that has Avocodo in its name. We will use this as reference and only make the necessary changes to use the new dataset. Look out for a variable called model_save_dir. This is the default directory that checkpoints will be saved into, unless you specify another one when calling the training script. Change it to whatever you like. Then pass the list of paths to the instanciation of the Dataset.

Now you need to add your newly created pipeline to the pipeline dictionary in the file run_training_pipeline.py in the top level of the toolkit. In this file, import the run function from the pipeline you just created and give it a speaking name. Now in the pipeline_dict, add your imported function as value and use as key a shorthand that makes sense. And just like that you're done.

Build a FastSpeech 2 Pipeline

In the directory called Utility there is a file called path_to_transcript_dicts.py. In this file you should write a function that returns a dictionary that has all the absolute paths to each of the audio files in your dataset as strings as the keys and the textual transcriptions of the corresponding audios as the values.

Then go to the directory TrainingInterfaces/TrainingPipelines. In there, make a copy of any existing pipeline that has FastSpeech 2 in its name. We will use this copy as reference and only make the necessary changes to use the new dataset. Import the function you have just written as build_path_to_transcript_dict. Since the data will be processed a considerable amount, a cache will be built and saved as file for quick and easy restarts. So find the variable cache_dir and adapt it to your needs. The same goes for the variable save_dir, which is where the checkpoints will be saved to. This is a default value, you can overwrite it when calling the pipeline later using a command line argument, in case you want to fine-tune from a checkpoint and thus save into a different directory.

In your new pipeline file, look out for the line in which the acoustic_model is loaded. Change the path to the checkpoint of an Aligner model. It can either be the one that is supplied with the toolkit on the release page, or one that you trained yourself. In the example pipelines, the one that we provide is finetuned to the dataset it is applied to before it is used to extract durations.

Since we are using text here, we have to make sure that the text processing is adequate for the language. So check in Preprocessing/TextFrontend whether the TextFrontend already has a language ID (e.g. 'en' and 'de') for the language of your dataset. If not, you'll have to implement handling for that, but it should be pretty simple by just doing it analogous to what is there already. Now back in the pipeline, change the lang argument in the creation of the dataset and in the call to the train loop function to the language ID that matches your data.

Now navigate to the implementation of the train_loop that is called in the pipeline. In this file, find the function called plot_progress_spec. This function will produce spectrogram plots during training, which is the most important way to monitor the progress of the training. In there, you may need to add an example sentence for the language of the data you are using. It should all be pretty clear from looking at it.

Once this is done, we are almost done, now we just need to make it available to the run_training_pipeline.py file in the top level. In said file, import the run function from the pipeline you just created and give it a speaking name. Now in the pipeline_dict, add your imported function as value and use as key a shorthand that makes sense. And that's it.

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Training a Model 🦜

Once you have a pipeline built, training is super easy. Just activate your virtual environment and run the command below. You might want to use something like nohup to keep it running after you log out from the server (then you should also add -u as option to python) and add an & to start it in the background. Also, you might want to direct the std:out and std:err into a specific file using > but all of that is just standard shell use and has nothing to do with the toolkit.

python run_training_pipeline.py <shorthand of the pipeline>

You can supply any of the following arguments, but don't have to (although for training you should definitely specify at least a GPU ID). It is recommended to download the pretrained checkpoint from the releases and use it as basis for fine-tuning for any new model that you train to significantly reduce training time.

--gpu_id <ID of the GPU you wish to use, as displayed with nvidia-smi, default is cpu> 

--resume_checkpoint <path to a checkpoint to load>

--resume (if this is present, the furthest checkpoint available will be loaded automatically)

--finetune (if this is present, the provided checkpoint will be fine-tuned on the data from this pipeline)

--model_save_dir <path to a directory where the checkpoints should be saved>

--wandb (if this is present, the logs will be synchronized to your weights&biases account, if you are logged in on the command line)

--wandb_resume_id <the id of the run you want to resume, if you are using weights&biases (you can find the id in the URL of the run)>

After every epoch, some logs will be written to the console. If the loss becomes NaN, you'll need to use a smaller learning rate or more warmup steps in the arguments of the call to the training_loop in the pipeline you are running.

If you get cuda out of memory errors, you need to decrease the batchsize in the arguments of the call to the training_loop in the pipeline you are running. Try decreasing the batchsize in small steps until you get no more out of cuda memory errors. Decreasing the batchsize may also require you to use a smaller learning rate. The use of GroupNorm should make it so that the training remains mostly stable.

Speaking of plots: in the directory you specified for saving model's checkpoint files and self-explanatory visualization data will appear. Since the checkpoints are quite big, only the five most recent ones will be kept. The amount of training steps highly depends on the data you are using, but 1,000,000 is usually pretty good for Avocodo and 200,000 is pretty good for FastSpeech 2. The fewer data you have, the fewer steps you should take to prevent overfitting issues. If you want to stop earlier, just kill the process, since everything is daemonic all the child-processes should die with it. In case there are some ghost-processes left behind, you can use the following command to find them and kill them manually.

fuser -v /dev/nvidia*

After training is complete, it is recommended to run run_weight_averaging.py. If you made no changes to the architectures and stuck to the default directory layout, it will automatically load any models you produced with one pipeline, average their parameters to get a slightly more robust model and save the result as best.pt in the same directory where all the corresponding checkpoints lie. This also compresses the file size significantly, so you should do this and then use the best.pt model for inference.

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Using a trained Model for Inference 🦢

You can load your trained models using an inference interface. Simply instanciate it with the proper directory handle identifying the model you want to use, the rest should work out in the background. You might want to set a language embedding or a speaker embedding. The methods for that should be self-explanatory.

An InferenceInterface contains two useful methods. They are read_to_file and read_aloud.

• read_to_file takes as input a list of strings and a filename. It will synthesize the sentences in the list and concatenate them with a short pause inbetween and write them to the filepath you supply as the other argument.

• read_aloud takes just a string, which it will then convert to speech and immediately play using the system's speakers. If you set the optional argument view to True when calling it, it will also show a plot of the phonemes it produced, the spectrogram it came up with, and the wave it created from that spectrogram. So all the representations can be seen, text to phoneme, phoneme to spectrogram and finally spectrogram to wave.

Their use is demonstrated in run_interactive_demo.py and run_text_to_file_reader.py.

There are simple scaling parameters to control the duration, the variance of the pitch curve and the variance of the energy curve. You can either change them in the code when using the interactive demo or the reader, or you can simply pass them to the interface when you use it in your own code.

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FAQ 🐓

Here are a few points that were brought up by users:

• My error message shows GPU0, even though I specified a different GPU - The way GPU selection works is that the specified GPU is set as the only visible device, in order to avoid backend stuff running accidentally on different GPUs. So internally the program will name the device GPU0, because it is the only GPU it can see. It is actually running on the GPU you specified.
• read_to_file produces strange outputs - Check if you're passing a list to the method or a string. Since strings can be iterated over, it might not throw an error, but a list of strings is expected.
• UserWarning: Detected call of lr_scheduler.step() before optimizer.step(). - We use a custom scheduler, and torch incorrectly thinks that we call the scheduler and the optimizer in the wrong order. Just ignore this warning, it is completely meaningless.
• Loss turns to NaN - The default learning rates work on clean data. If your data is less clean, try using the scorer to find problematic samples, or reduce the learning rate. The most common problem is there being pauses in the speech, but nothing that hints at them in the text. That's why ASR corpora, which leave out punctuation, are usually difficult to use for TTS.

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The basic PyTorch Modules of FastSpeech 2 are taken from ESPnet, the PyTorch Modules of HiFiGAN are taken from the ParallelWaveGAN repository which are also authored by the brilliant Tomoki Hayashi.

For a version of the toolkit that includes TransformerTTS, Tacotron 2 or MelGAN, check out the other branches. They are separated to keep the code clean, simple and minimal as the development progresses.

This toolkit has been written by Florian Lux, if you come across problems or questions, feel free to write a mail. Also let me know if you do something cool with it. Thank you for reading.

Citation 🐧

Introduction of the Toolkit [associated code and models]

@inproceedings{lux2021toucan,
  year         = 2021,
  title        = {{The IMS Toucan system for the Blizzard Challenge 2021}},
  author       = {Florian Lux and Julia Koch and Antje Schweitzer and Ngoc Thang Vu},
  booktitle    = {{Proc. Blizzard Challenge Workshop}},
  publisher    = {Speech Synthesis SIG},
  volume       = 2021
}

Adding Articulatory Features and Meta-Learning Pretraining [associated code and models]

@inproceedings{lux2022laml,
  year         = 2022,
  title        = {{Language-Agnostic Meta-Learning for Low-Resource Text-to-Speech with Articulatory Features}},
  author       = {Florian Lux and Ngoc Thang Vu},
  booktitle    = {{Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics}},
  pages        = {6858--6868}
}

Adding Exact Prosody-Cloning Capabilities [associated code and models]

(accepted, not yet published)

@inproceedings{lux2022cloning,
  year         = 2022,
  title        = {{Exact Prosody Cloning in Zero-Shot Multispeaker Text-to-Speech}},
  author       = {Lux, Florian and Koch, Julia and Vu, Ngoc Thang},
  booktitle    = {{Proc. IEEE SLT}}
}

Adding Language Embeddings and Word Boundaries [associated code and models]

(accepted, not yet published)

@inproceedings{lux2022lrms,
  year         = 2022,
  title        = {{Low-Resource Multilingual and Zero-Shot Multispeaker TTS}},
  author       = {Florian Lux and Julia Koch and Ngoc Thang Vu},
  booktitle    = {{Proceedings of the 2nd Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics}},
}