kaia-chara 5.0.0

ML-Pipelines architecture and implementation for paraphrasing and voice cloning

Table of contents

• chara
  • General concepts
    • Caching
  • Integrations
  • Cases
• Paraphrases
  • paraphrases.common
  • paraphrasing.utterances
• Voice Cloning

chara

Chara is a collection of research scripts that are primarly used to create characters.

Currently, two branches are covered:

• Paraphrasing. This is used to paraphrase the outputs of Kaia so that they match to the personality of the character. The pipeline will take the replies from the assistant, take the previously generated paraphrases from Avatar server, determine which replies need more coverage, paraphrase them and upload the results back to the Avatar server. All you need to do is to define the characters and their personalities. Under the hood, this system generate the paraphrases for arbitrary grammatron Templates, which can be used elsewhere: e.g. we also use it in natural-language understanding research.
• Voice cloning will help you to create character's voices. It will take the voice sample of your character, then the GPU-requiring zero-shot voice cloner generate an hours-long dataset of phrases, and then the lightweight Piper model will be trained on this dataset.

Both systems support different languages. Currently German, English and Russian are implemented, others can be added with some additional effort.

For the detailed description of these project, please consult the README.md files in the respective directories.

General concepts

chara infrastructure offers a way to write the reproducible, maintainable and deliverable research. Traditionally, the research is often done in notebooks, and while they are very handy for research, they are also terrible in production. It's hard to pass the parameters to the notebook, or to write a unit tests for it, or to call one notebook from another, etc. Hence, the code is often rewritten as a pure Python, but then it loses the benefits of the notebooks: visualizations that may still be useful in production for the quality control. Also, after the conversions, the intermediate values are no longer cached in memory, and so if your several hours long pipeline gives incorrect result in the end, it's not possible no understand why. Also, it's impossible to fix the bug and restart the pipeline from the partially computed state.

I've been suffering from these problems for quite awhile, and chara became a simple and efficient solution. First, foundation_kaia.logger provides a logger that can consume plots, dataframes and ipynotebook widgets and output them to the HTML files. This way you can still enjoy your intermediate visualizations, copied straight from notebooks.

Second, chara offers the caching infrastruture, seamlessly build over the functions call.

Caching

If you need to cache the results of the function(*args, **kwargs), just write Chara.start(folder), and then Chara.call(function)(*args, **kwargs). This will cache the returned value of function in the folder, so if the function is called again, the value will be restored and function won't be called again. If function calls other functions inside with Chara.call, the subfolders with the interpretable names will be created to cache the results of the internal calls. In case something went wrong, you can invalidate the cache: invalidate_self(path) will invalidate the result of the function's call, but not the results of the inner calls, while invalidate_down will reset the associated cache completely. Also, these functions remove the caches of all the functions called after the desired path, and remove the cached results of all the function up on the stack, so basically this corresponds to "repeat the pipeline from the selected place".

Obviously, caches need a bit of architectural redesign of the code, e.g.

1. If the code is called with the different parameters, the folder needs to be changed or reseted
2. The code shouldn't have branching on the Chara.call calls. If you need to conditionally run the function, call it anyway and return None.

In addition, you may use the Chara.phase decorator to subdivide a function without extracting functions from them:

def function(argument):

  @Chara.phase
  def first_formula():
    return argument + 1

  first_result = Chara.last.result

  @Chara.phase
  def second_formula():
    return first_result * 2

  second_result = Chara.last.result
  return 1 / second_result

This will create two caches, for the first_formula and the second_formula, and store the intermediate values there.

Finally, all the functions can get the access to the current folder with Chara.current. That allows to store some additional files there. Since chara pipelines work with media, they are quite heavy on files, and this functionality is very handy.

Integrations

There are some important integrations that offer you the basic building blocks for your pipelines. The most important ones are BrainBox integrations. brainbox_training_pipeline runs the training process (such as e.g. PiperTraining.train), monitors the progress and interprets the results. brainbox_pipeline accepts the Iterable of tasks, adds them to the server, and then stores the pickled results in the tar file, without placing it in the memory at once. If the result of the task is file or several files, the pipeline downloads these files from the server, and in this case the paths of the downloaded files will be stored in the tar file. This tar file can then be iteratively read, again, without placing its content in the memory at once.

Cases

Most of the integrations implement the pattern of ICasePipeline: they accept the list of cases (essentially, arbitrary dataclasses), modify the cases (or replace with other cases), and return the updated collection or the same one. This is extremely convenient when you need e.g. to run several BrainBox tasks that are associated with, e.g. a particular file, and then bring together the results. BrainBoxCasePipeline does just this: builds a task for each case, and then places the result of the task to the case's field.

AnnotationPipeline is also very useful. When working with GenAI, it is often needed to annotate data, e.g. rejecting some of the data points by quality. AnnotationPipeline accepts the list of the cases, displays each case and collects the feedback. Display is done via IAnnotator, and right now a Gradio-based GradioLabelAnnotator is available.

There are also collective actions on the cases. Such pipelines accept inner_pipeline: ICasePipeline, and:

• RepeatUntilDonePipeline calls inner_pipeline several times on the array of the cases, excluding those cases that received a non-erroneous answer.
• ChooseBestAnswerPipeline calls inner_pipeline several times on all cases, then select the most popular answer. This is handy if you need the LLMs to vote on the result.
• BatchingPipeline selects several cases from the bigger subset and calls the inner_pipeline on them, thus providing the manageable execution time of each batch and control over when to stop the process.

Paraphrases

paraphrases.common

This pipeline paraphrases the grammatron.Template, possible also translating it to other languages.

First, templates undergo paraphrasing.

• The input case contains Template and covariates that are used in the prompt.
• The template is parsed into one or many ParsedTemplate, the case is split if necessary. Each ParsedTemplate contains all the lines with the same set of variables. E.g. if the template has lines "Set the timer", "Please create a timer" and "Set the {index} timer", there will be two ParsedTemplates: one for "Set the timer" and "Please create a timer", and another for "Set the {index} timer". The order of the variables does not matter.
• The cases are fed to the TemplateParaphrasing. For each case, a multiple lines of possible variations is given. The case is split again, one case per each variation.

Then, in case it's translation, following steps are needed:

• If the template has options, these options need to be translated
• If the template is translated to German or Russian, the grammatical form needs to be determined for each variable. To get basic understanding about grammatical forms, consult grammatron documentation. The grammatic correction essentially asks LLM several times what is the correct casus/article, and select the most popular answer. It doesn't work flawlessly though.
• In some use cases, like dataset generation one might need to additionally create more options for the OptionsDub.

These settings can be configured in the Paraphrase.Settings class.

paraphrasing.utterances

This is a production-ready script that is supposed to operate on a live Avatar Server, where your Kaia is running, and a BrainBox server (that will probably be a different one from Kaia instance, since a good GPU is required for LLMs).

The entry point is UtteranceParaphraseCase that contains:

• a template (they come from KaiaAssistant.get_replies)
• list of Character definitions: for each character, you need a name and a short story
• optional list of users, also specified by Character.
• dictionary of relationships between characters and users
• target_language: ru, de, or en. Right now, Kaia is not ready to fully handle multiple language (the deficit is at NLU part)

After that, create Paraphrase.Settings, then UtteranceParaphrasePipeline, and run it.

It will connect to the Avatar server and dowload existing paraphrases and their usages statistics. Then, it will determine which templates are in need of paraphrasing, create the paraphrases and upload them to server. Reloading of the KAIA GUI interface will trigger the reloading of ParaphrasingService on the server side, and new paraphrases will become available.

paraphrases_upper_count parameter manages the paraphrasing: no templates with more paraphrases than this amount will be taken into account. Set it to 0 if you added some new templates and want only them to be paraphrased. Set them to e.g. 30 to ensure that every template has at least 30 paraphrases. Without this parameter, the paraphrasing will continue until max_attemps, prioritizing the templates that are in the heavy usage.

Voice Cloning

Voice Cloning is used to give your character a local and low-compute voice. There are many cloud services that perform the voiceover, but they are paid and often restricted.

In voice_clone.common, several local systems are integrated as Chara pipelines. These integrations address peculiarities in the systems' requirements to the training data or inference parameters. For quite a while, the local voice cloners couldn't match the cloud services in terms of quality or language coverage, but CosyVoice closes this gap, producing excellent voiceovers in many common languages.

However, running CosyVoice requires GPU, and this is not what we aim for the assistant. We need a lighter model, Piper, that can run on the CPU and on Raspberry Pi, but cannot do zero-shot voice cloning: instead, it needs to be properly fine-tuned on 1+ hours of data for each character. So we create this dataset with CosyVoice, and then train Piper.

voice_clone.dataset produces the text dataset, that is later voiced over by CosyVoice. This step is needed, because the voiceovers need to represent all the phonemes of target language, ever rare ones. The algorithm is employed to select the sentences so that all the phonemes are well-represented. Also, it's important that no foreign words were added to this dataset, because e.g. for German CosyVoice tends to pronounce anglicisms in pure English, not in German, thus reducing the quality. This is why the sentences also need an additional review.

voice_clone.upsampling creates the voice dataset:

• It adds prefixes and suffixes to each line of the text dataset (many systems, including CosyVoice, tend to stutter or produce noises at the beginning and the end of the text, so the prefixes and suffixes are buffers for this stutter, and will be later removed)
• Voices over the modified line
• Converts the voiceover back to text with VOSK to:
  • detect the cases that are voiced over plainly wrong (sometimes CosyVoice produces the voiceovers that have nothing to do with the text)
  • detect the usable part of the voiceover without suffix and prefix
• Then, the files are exported to the archive in the format that is needed by PiperTraining.

voice_clone.training runs the training, and obtains several checkpoints. Then, the evaluation procedure uploads each of these checkpoints to Piper, voices over a boilerplate text, and outputs the results in the HTML format. You can check this file and select the checkpoint you like most, or increase/reduce the amount of epochs required. After achieving a good quality, the model may be uploaded to Piper again, manually, with the proper name of the character. Then, kaia.app.avatar_daemon_settings may finally be changed to set the list of the characters to yours, and map the models' names to the characters.