GSoC Ideas 2019

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Google Summer of Code (GSoC) is Google's program for promoting Open Source Software development. Audacity was a mentoring organization for five students for Google Summer of Code 2008, and mentored two students in 2009. This page contains our ideas for suitable projects for 2019.
For information about our future plans and about Audacity software development, please join our developers mailing list
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Executive Summary

We have 11 seed ideas in the green table, for this years GSoC.

  • These focus on the benefit we want from your work.
  • You will need to provide the detail, and convince us you have the skills to develop the chosen seed idea into a full completed tested project.


The Audacity audio editor is downloaded around 18 million times each year. It's a large, mature and clearly popular open source project. In 2008 and 2009 we participated in Google's Summer of Code, with 5 students in the first year and 2 in the second. If we participate in 2019 we will likely try to mentor two students, so that we can give them enough attention that they have both challenges and every chance of success.

In many ways Audacity has 'grown up' between 2008 and now. We've become more quality conscious. We've become more aware of both the need to and how to bring on new developers. Because of this we've changed what we ask for in project proposals. Your project proposal *must* be presented as a collection of smaller features each of which is useful in itself. It's no good proposing one single big change which can't be trialed by end users during the GSoC period. A mix of smaller related features - along with related bug fixes is good. If your proposal is different to that, if it can't be broken up into smaller useful pieces, if it does not include any bug fixing, or if the pieces are not related and working as a whole, you'll have more trouble convincing us that it will be successful.
We *expect* incremental development, with near-daily check ins to GitHub of work in progress, and work that is ready enough that your mentor can easily try it out. In return, mentors will be available to guide and give feedback. We work by email, not IRC nor video chat. It's what works for us.

Idea Seeds

In past years we provided pretty well fleshed out proposals as starting points.
  • We expected applicants to provide more.
  • We found that some students just echoed our proposals back to us, making it hard for us to tell if the student had any knowledge or interest.

This year we are providing seed project ideas. They ARE fairly well worked out by us, BUT to apply with one of these ideas you will need to do some work too. That's the 'show us you can...', though you are welcome to find other ways to show us that you can do the project.

  • To grow the seed you will need to hunt through our code and read Proposals on this wiki.
  • We have a developer section on this wiki with information to help you find your way around.
  • You will need to compile Audacity, and show that you can code.

Personality Matrix

Icon Profile Catch Phrase Mentor BOLO


Lower risk, on core components.
Safe incremental improvement.
"Steady as she goes" Good progress early on.


Higher risk, and on core components.
Possibly big payoff.
Hoping to 'hit gold'. Good fallback, if main plan does not work out.


Fun, low risk changes, away from core. We'll find the route. Useful spin offs, early on.


Fun, higher-risk-of-failure work, away from core.
Possibly radical transformation. Possibly big payoff.
Abracadabra! Tangible benefits to project at Mid-Term, to keep project rooted in reality.

Seed Project Ideas

In a GSoC proposal, a key element is the 'Show us You can'. We need to be convinced you have what it takes to complete the project successfully.

Name Personality Type Speciality? Idea High Level Benefit Show us you can...
Nouns and Verbs


Architecture Audacity classes often mix data (nouns) and functions (verbs).
  • Propose and, after approval, implement specific refactoring that enhance the distinction.
More interface flexibility and fewer special cases.
  • Show us which classes would benefit most from this and say why.


Maths Find ways to code Audacity at a higher more mathematical level.
  • These changes must have measurable benefits, such as reducing code size, or providing more options with the same amount of code.
More Audacity functionality for less code.
  • Show us where we have repetitive code that could be reduxed.
Build Systems


SCONS or CMake Fix and document our build system Less time wasted on build-system gotchas.
  • Explain to us what would change with the new system.


An RTL Language Get Audacity working well with a Right-To-Left language. Support for Hebrew or Arabic
  • Show us which classes would benefit most from this and say why.


Integration Enhance our homegrown (MIT Licensed) WIT system that we use in-house for easing test, production of images and documentation. Improve our web-based tools for developers and support.
  • Spell out how the enhanced system would save us more time or enable us to do more with the same effort.
Hard Test Automation


Test Identify the hardest things to test automatically, and propose and implement solutions. Increased confidence in hard to test areas.
  • Show us something you could do in this line.
Bear Traps


User Interaction Fix our various (User) Stuck-in-a-mode Issues. Fewer traps for the unwary in our GUI
  • Organise the bear-traps showing your preferred option for fixing each.
  • Fix one to show you can.


SQL Offer SQLITE as a BlockFile alternative. Problem with fragmented projects gone.
  • Show where it would slot in to existing code.


Machine Learning Offer GUI enhancements for working with machine learning
  • Aim to entice researchers. They plug in ML feature detectors etc, and don't have to write GUI.
  • The GUI enhancements MUST have relevance to ordinary users too.
Text-to-Speech and Speech-To-Text GUI support. Present a plan that shows:
  • What GUI features would be provided, and why.
  • How GUI would be developed and tested.
Error Analysis


Cause Analysis Find patterns in the kinds of bugs we report. Implement measures to fix categories of errors, and avoid them in future. Whole error categories identified, and preemptively fixed.
  • Do a small part of it already.


Metering Design and implement measures that monitor and report on headroom, rather than as now, detecting failure when it happens. Measurements of leeway, and hence earlier warnings.
  • Set out a plan of what you would measure, and where in the code you would measure it.

Familiarisation Tasks

Smaller tasks that give familiarity with code. These are much smaller than a GSoC, but still useful to Audacity team.

Name Description
'true/false' synonyms. Many functions have bool parameters. A function call like DoUpdates( mMessage, true, false, false ); is not self documenting. Fix it.
Coding standards Apply Google's C++ coding standards to the naming of variables in the main code.
WAV formats The method for setting sub options in WAV file output is not very discoverable. Propose and implement a fix.

Pure Feature Project Ideas

In the past we thought GSoC was about new features. We weren't entirely wrong. Applicants for GSoC are welcome to pitch pure feature project ideas to us. The problem is that it is extremely hard to complete a new feature to release ready standards in the time of a GSoC. We do need the work that GSoC students do to be ready for release. Hence our new focus on seed projects. If you do propose a feature project, you must plan to have it demo-ready by the mid term. Taking a new feature from demo-ready to release ready can easily take half of the GSoC time. We are proposing that big features be implemented as plug-ins. That way the risk to you and us is reduced. There is lower risk of them destabilising core Audacity. We also have the option of releasing an experimental plug-in that is not quite ready for mainstream use by millions of users.

Name Difficulty Idea High Level Benefit Show us you can...
Oscilloscope Mode Medium Improvements to scrolling and zooming behaviour for close up work. In particular in Oscilloscope mode
  • Done.png The 'play' or 'record' line will stay still and the wave form scroll past.
  • At high zooms this will only look good if the section to show with each refresh is chosen carefully, picking up in some easy to compute way on some regularity in the audio sounds.
  • Some performance improvements in drawing the graphs would help make this mode possible on lower powered machines.
Gives users better insight into their audio.
Audio Diff GUI Plug-In Hard Ability to compare and align two sound sequences just as one compares text using diff would be a powerful new feature in Audacity. It would greatly facilitate the combining of sounds from multiple 'takes' of the same track. It would also be of use to people looking to identify particular known sounds, e.g. repeated themes in birdsong, in very long recordings.

We proposed implementing Audio Diff including a GUI for it as a project idea for GSoC 2008. It was the most challenging of the ideas offered then. This year the focus is on the GUI side of audio diff. An existing audio diff algorithm could be ported or a very very simple one used as a demonstrator. The key extensions are in the interface so that diff becomes a useful tool. The interface will probably need to extend what we already do with multiple clips on one track. It is likely there will be a 'dotplot' display mode and an 'alignment' display mode.

Paves way for cutting-edge remix feature.
Vowel Quadrilateral Plug-In Moderate/Easy

The vowel quadrilateral is one step in making Audacity more useful as a tool for foreign language learners. Long term we want to make Audacity part of a language learning eco-system. The vowel-quadrilateral project would also act as a driver for creating a real plug-in architecture for Audacity. Part of the project would entail converting some existing features, such as the karaoke display and cleanspeech into plug-ins. The project could be expanded to involve some collaboration with RockBox to work on mark-up of audio for language learners.

Helpful to language learners.
Custom Developer Tools Moderate The key ingredient in this proposal is software that make Audacity developers more effective. This is seen as being of strategic importance to the future of Audacity. Some possibilities include:
  • Collaboration with wxFormBuilder to make a theming tool for easy changing of the skin of Audacity.
  • Done.png Enhanced built-in screenshot tools for documentation.
  • Enhancements to Doxygen output modes so that we can present more relevant and more dynamic information about Audacity architecture to potential developers.
Faster / Easier development.
Hierarchical Track Panel Moderate An experimental start has been made on this, but it needs to be taken a lot further. The key feature is to have a tree-like structure for a project with sub-mixes within the tree. The developer will need to break the TrackPanel class into smaller classes to get this level of flexibility. Better for users with many audio tracks.

More Ideas

See Release Checklist for an understanding of what we need to do...