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RJ Skerry-Ryan edited this page Apr 24, 2013 · 47 revisions

Student Project Ideas for Google Summer of Code 2013

This page lists the suggested projects for students working on Mixxx as part of Google Summer of Code 2013. Each of these projects represents something that we think would make a really big difference to our users and that we as a development team are really excited about. For advice on how to get in touch and how to apply, you should read GSoC Advice.

A GSoC application that simply repeats the project description will NOT be accepted. We expect you to think about the feature and how it aligns with Mixxx's goals, outline potential use-cases and propose a plan for implementing a solution.

Cover Art Support

Over the years a highly requested feature has been for Mixxx to support displaying cover art. This is a great project that combines both aesthetics/design and engineering. Can you think of awesome, playful ways to display cover art?

Some topics your proposal should cover:

  • Supporting loading cover art (from metadata tags, from cover images in album directories, etc.)
  • Deciding where and how to display the cover art in the GUI.
  • Downloading cover art from metadata sources on the Internet if it is not available locally.

Your proposal should at the very least include details of how you will accomplish each of these parts of the project but the project is by no means limited to these topics. Make sure to think through the whole design and implementation and be sure to include details of anything you think may be relevant.

Since this project is small in scope, we expect that you will have plenty of time to polish it and make it shine.

Links to Launchpad bugs:

Plug and Play MIDI Mode / Community MIDI Mappings

Mixxx currently supports a wide-range of hardware MIDI controllers that DJs can use to perform with. Each supported MIDI controller has a "mapping" file that is bundled with Mixxx, but this mapping must be manually selected by the user before their controller works. The aim of this project is to increase the usability for new users by automatically selecting the correct MIDI mapping and to provide an intelligent workflow for when an unsupported MIDI device is connected.

When a mapping for a MIDI device is not present, the user should not be left out in the cold. She should have the option of connecting to to see if there are any official or user-contributed mappings available for download. It's easy to imagine the various interesting turns this could take.

Since there is a server-side component to this project we ask that applicants be familiar with a web development framework that would be suitable for writing an API for We suggest Django.

This project will involve a lot of time thinking about use cases, dealing with users and understanding their requirements. It would be a great opportunity for a student to get involved with the Mixxx community. The student will also have the opportunity to borrow a MIDI controller from the development team for the duration of the project.

Loop Recorder

A Loop Recorder is a module that allows the DJ to record short segments of the audio output (decks, cue/headphones, main output, etc.) and then play-back and remix the recorded segment into their mix. This is a key element of many controllerist and scratch routines.

This project will involve mostly architectural changes to the Mixxx mixing engine so digital signal processing experience is not a pre-requisite. In the process of writing up your proposal, we expect you to flesh out the different use cases you can think of for the loop recorder. Make sure to explore the Internet a little bit to find out more about what people use loop recorders for, specifically in a DJing context.

Some related bugs on Mixxx's bug tracker can be found here:

Cloud Library Support (SoundCloud, Spotify, etc.)

There are many music discovery services which give users access to a broad library of music. Many of these services have APIs that allow 3rd-party clients to access the library and download music on the behalf of the user. We think these services will be a powerful tool for our users to explore how songs fit in their mixes.

Your application should include details of which streaming services you plan to integrate and how you will make use of their download/streaming APIs (if they exist). We are not looking for dedicated integration of a service (for example, we aren't looking for a SoundCloud or YouTube section of the Mixxx library) -- rather we envision a generic "Internet Tracks" section of the library where users can search across all of their enabled cloud library services to find and play tracks.

In the very least, your proposal should define a modular system for plugging in new streaming services so that in the future all that is required to add more is defining how to search and download from the API of the new service. Also consider what will be most useful to a DJ and contact us on our mailing lists with your ideas.

Note, that due to technical restrictions streaming music in the Mixxx engine is very difficult. Your proposal should leave room in the future for streaming but in the implementation you write it should support download of the music to a temporary storage location for playing. This has the added bonus that it ensures there are not hiccups in the audio due to a bad Internet connection.

Some related bugs on Mixxx's bug tracker can be found here:

Keyboard / MIDI Mapping GUI

In Mixxx 1.11.0 we removed the old MIDI mapping GUI as we re-wrote the controller subsystem to support HID devices. Now it's time to rewrite the mapping GUI! This GUI should be modular enough to support an HID mapping GUI in the future. In previous versions of Mixxx the keyboard mapping was accomplished via a text file. This project will move keyboard mapping and processing into the new controller sub-system as a new type of controller and introduce a user-friendly GUI for editing keyboard presets and MIDI presets. For backwards compatibility, the keyboard presets should still be stored on-disk in the same text format.

We suggest you check out the MIDI mapping GUI present in Mixxx 1.10.0 and think of ways to improve on it. For example, one very user-unfriendly aspect of it was that you had to know the ControlObject names of the controls you wanted to connect to a MIDI message. The point-and-click MIDI mapping wizard in 1.11.0 now includes a drop-down of all mappable controls. This is a much better way for users to decide on what control to map a message to. Another very useful exercise is checking out the various commercial DJ software offerings out there and examining how they allow users to map MIDI controllers.

Enhanced Platform Integration

Thanks in large part to Qt and a number of other cross-platform libraries, Mixxx runs on Windows, Mac OS X, and Linux. Although we're able to provide a consistent user experience on all three platforms, we'd like to provide a better integrated experience. We want to take advantage of the unique features that each platform provides, like the new fullscreen mode in OS X Lion or the new jump list in Windows 7 or gvfs in Linux, so that Mixxx feels as native as possible.

Qt already provides a small number of platform integration features, but to take advantage of other newer features that Qt doesn't have, platform-specific code for Windows, Mac OS X und Linux must be added to Mixxx. This project will involve figuring out which platform-specific features in Windows 7, Windows 8, Mac OS X Lion, and Mac OS X Mountain Lion would be the most useful for Mixxx users, and implementing several of those. (We don't expect students to have access to both Linux and Windows and Mac OS X, so a proposal focusing on one particular OS is OK, but an awareness of all platforms is a plus.)

This project could also include more basic polishing tasks, so if there's some little inconsistencies about Mixxx that have been bugging you, here's your chance to fix them.

For ideas, check out:

Intelligent Track Suggestions

The single most important use-case of the Mixxx library is to help the DJ select the next track to play. Sadly, today Mixxx doesn't do a great job of helping the DJ in this capacity -- Mixxx provides her with fast ways to search and sort through her music library but it could do much more.

The goal of this project is to build a new feature into the Mixxx library that ranks tracks by how well they match the current mix. This ideally helps the DJ narrow down the candidates to a short list of tracks to pick from.

Your proposal should include specific details of how your feature will work (for example, what signals you will use for ranking tracks, how the user interface to the feature will look, etc.).

Related Links:

Advanced Track Management / Organization Tools

Today, Mixxx provides DJs with limited tools for organizing their library. Mixxx reads file metadata and stores track information in its SQLite-based library. DJs are able to sort and search through their music and organize the tracks into Crates and Playlists.

Editing of metadata can be done inline in the library and with the Track Properties editor. These are fine for simple edits, but they should allow the DJ to do much more.

This project aims to massively improve/replace the track metadata editor built into Mixxx and make single or bulk editing of tracks much easier.

Your proposal should include a clear description of the shortcomings of today's editor and how you plan to improve it. If appropriate, please include mockups and diagrams illustrating your plans.

Some important questions to consider:

  • What information does Mixxx store about tracks (both DJ-related and non-DJ-related)?
  • For example: Crates, hotcues, loops, album, artist, etc.
  • What is the simplest user interface to allow the DJ to edit this metadata?
  • How will you handle single-track editing versus bulk editing?

Non-Blocking Database Access

Currently some database transactions are stalling the GUI. This is because some database queries are preformed from the GUI thread.

This should be solved during the project by something like a standard non blocking interface to sqlite. All Database queries should be issued though this new interface.

This project would make Mixxx more reliable by this new concept how to deal with database actions.

Your proposal should include a draft proposal how do you will achieve the goal. You should have already have experience in parallel processing and sqlite.

Library GUI Layout Redesign

The current library GUI needs to be polished and needs to give room for new features.

You find everything relevant collected here

The current GUI proposals at are the result from our last design work. It should give a clue what direction we will go. But please make them to your own. What do we need most form your experience with Mixxx?

The current code driving the library is hard to maintain because it was growing along with Mixxx. Here is a concept required, how we could make it again maintainable and extendable. You should have Qt experience and a clue about Qt's implementation of the MVC pattern.

A great source for design hints is also the code from Qt based media players e.g Clementine or Tomahawk,

The difficulty of this project is focus on the daily DJ Us cases, but allow also crazy new features, without clutter the GUI. Maybe you should tell the story how the GUI will be used.

Something Else!

As always with Summer of Code, you aren't limited to the suggestions we've made here. If you've got a great idea for a project involving Mixxx then we're looking forward to hearing about it. Our bug tracker is full of wishlist bugs and other ideas scattered throughout, so if you browse through it, you may find many more ideas for GSoC projects.

IMPORTANT: You should contact us first to get feedback if you're going to submit a proposal for your own project idea!

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