GSoC Ideas 2008

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Revision as of 21:11, 16 March 2008 by James (talk | contribs) (Promoted Nyquist, Vamp and Rivendell. Demoted Postfish.)
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Getting in Contact:
  • We have this email address  for Google Summer of Code enquiries. This will reach those developers involved in organising Summer of Code for Audacity. This address is suitable for general queries if you just want to find out more about what may be involved in being a GSoC student. Answers to some questions we have already been asked can be found at our own GSoC FAQ.
  • We also have an active developer list here . We strongly encourage technical discussion of ideas on the devel list. You are likely to get more feedback and more detailed responses to your ideas if you introduce yourself to that list and state what your interests are. Note: To post to this list you do need to subscribe to it (we made that choice to avoid spam).
  • If you want to participate in GSoC 2008 with Audacity, please put your name and the institution you are at on our Potential GSoC Students page. This lets us (and Google) gauge the degree of support we have. You'll still need to send in a student application to Google in due course to be considered. Your application can be submitted via the GSoC web app between March 24-31, 2008.


Generally, do get in contact and discuss your ideas with us well in advance. This greatly increases your chance of being accepted.


Ideas

Possible Mentors These are, in order, the most likely or best mentors for this project idea.
Skills For nearly all project ideas, wxWidgets and C++ programming are essential. Some projects need additional skills too.
Difficulty 'Easy', 'Moderate' or 'Hard'.

Hard tasks can be made easier by solving a simpler problem. That's a decision that needs to be made early on. 'Easy' problems are lower risk. They are better suited to being done in separate smaller pieces if the going gets tough. So take the 'difficulty' grading with a grain of salt. It's only a guideline of how hard we think the problem is.

Early Spinoffs We regard it as vital that projects have early spinoffs that can be completed well within the time. These early spinoffs help to ensure that the code is useful to us. We don't want to end up with 'almost complete' code that we cannot use!


Below is our current pick of project ideas.

Feel free to suggest your own ideas as well.

  • It would be best to write the first version on More GSoC Ideas, following the same format.
  • When the idea is well defined and mentors have been found, it can be moved to this page.


Label Track Enhancements

Possible Mentors:

Description: Audacity has flexible Label tracks for annotating sections of the audio. The method for positioning and dragging the labels allows the same kind of labels to easily be used to label points, ranges, and also maintain boundaries between regions by dragging two end points at the same time.

We're looking for proposals for the next stage of enhancements, that integrate them more into the audio editing process. Possibilities to consider include:

  • More operations on labels, such as 'apply effect at labels'.
  • Visual enhancements, such as different icons and colours associated with different kinds of labels.
  • Handling of very large numbers of labels. This requires both optimisations and new visual options.
  • Snapping of labels, so that they position at specified time intervals.
  • New ways to automatically compute labels.

A detailed proposal should make clear the Use Cases for the enhanced labels that are motivating the changes.

Skills:

  • wxWidgets and C++

Difficulty:

  • Easy. Improvements can be made in small steps.

Early spinoff from this work:

  • Label tracks to stick to the track above, so that they edit together.


Play-Back Enhancements

Possible Mentors:

Description: Audacity lags behind commercial audio software in a number of details of its play back behaviour. Specific enhancements we would like a summer student to provide are:

  • No 'click' on start/stop/loop; At the moment there usually is an audible click when Audacity starts or stops playing a sound, or in iterations of playing a loop. A very short fade-in and fade-out applied only to playback should fix this.
  • Loop play adjusts dynamically to boundaries being moved; Finding the precise boundaries of a sound, for example an unwanted sound to be fixed, can be difficult with Audacity as it currently is. The location of the sound isn't obvious from the waveform. The new option would allow playing the sound in a loop, adjusting the boundaries to find out exactly where it starts and stops.
  • Vari-speed playback; Fast playback of sound allows sections of audio to be located more rapidly. Slow playback allows precise location (on timeline) of sound to be determined more accurately. There is a crude version of this on the 'Transcription Toolbar' - refining it would include allowing the speed to vary during playback without starting and stopping.
  • Drag-playback-cursor whilst playing; This requires changes to both playback and GUI. It is an extension of vari-speed playback and would make locating sound more rapid.
  • Play all 'labels' on the selected label tracks; Labels can be placed on the Audio both manually and automatically. This has many uses, one being the possibility of previewing a recording whilst skipping over periods of silence.

Skills:

  • wxWidgets and C++

Difficulty:

  • Moderate. Easy to vary the difficulty in either direction through choice of what to implement.

Early spinoffs from this work:

  • The schedule should plan to have some features complete to the 'release candidate' phase by the half way point. This is more useful than progressing all of the features in tandem, and perhaps completing none of them if time runs out.


Bridges

Possible Mentors:

  • Federico Grau (for Rivendell); Bartek Golenzo (Octave).

Description: One way to grow the feature set of Audacity and at the same time to avoid re-inventing the wheel is to build compatibility 'bridges' between Audacity and other Open Source programs. This is an example of making Connected Open Source a reality. Two examples of bridges for Audacity are:

  • Bridge to Octave - Octave is an Open Source program for mathematical analysis and is useful in digital signal processing (DSP). Audacity could have a bridge to Octave that allows Octave to apply effects to Audacity waveforms and to annotate Audacity waveforms with labels.
  • Bridge to Rivendell - Rivendell is an Open Source program for radio station management. The Rivendell bridges already allows Audacity and Rivendell to exchange play-lists. Work on it would improve the integration.

A proposal for a new bridge should go into some detail as to what features of the other program will be bridged. Generally the plan should avoid extensive work on the other program, since the point of the project is to extend Audacity.

This is part of the Connected Open Source initiative, aiming to build more bridges between Open Source projects.

Skills:

  • wxWidgets and C++
  • Familiarity with Octave or Rivendell or other software being bridged to.

Difficulty:

  • Moderate to Hard. Student has to get familiar with two programs.

Notes:

  • The Octave bridge is probably too difficult to do without a mentor who is very familiar with Octave, and so unlikely to go ahead unless we find a mentor for it in the time.

Early spinoff from this work:

  • A restricted bridge which exposes a smaller part of the functionality.


FFmpeg integration

Possible Mentors:

Description: A patch has been produced in the past to use FFmpeg libraries for importing and exporting audio files in a wide variety of audio formats. This however was against 1.2.x and will require considerable changes to integrate it with current audacity code. There will also be issues surrounding the build system and ensuring license requirements are met when distributing the resulting program.

  • Import needs to decode the imported files into audacity, handling varying channel counts sensibly.
  • Metadata in imported files should be fed into the audacity meta-data handling so it can be stored, edited and used for exported files.
  • A decision is needed on what to do if video files (with and without sound tracks) are presented.
  • Export will need to work out how to provide a user interface to handle choice of codec and container formats.
  • Export should cater for multi-channel output where applicable with more than 2 output channels, using the export routing code already in place.
  • Export needs to write relevant metadata to the exported file from the available audacity metadata and user interface.

Skills:

  • wxWidgets and C++
  • Must be prepared to work on both Windows and Linux and ideally Mac OSX too.

Difficulty:

  • Moderate. (Assuming nothing is done with video and the interface is kept simple).

Early spinoffs from this work:

  • Importer is probably easier to do and independent of export. Adding an importer should not be terribly hard to do, at least for mono and stereo files which covers most use cases. No interface modifications needed to do this, and enabling / disabling it at build time is clean and follows other importers.
  • Metadata support can be implemented after other parts are complete / working.


Nyquist update

Possible Mentors:

  • Roger Dannenberg

Description: Upgrade Nyquist support to latest version.

Nyquist is a version of the LISP language built into Audacity.

Skills:

  • C++.
  • Developing on Linux and Windows.

Difficulty:

  • Moderate.

Early spinoff from this work:

  • Demonstrate the upgrade on one of the two platforms.
  • If there are no unanticipated hitches, the project will be easily achievable in the 8 weeks. A good project proposal based on this idea should include other improvements for the Audacity Nyquist user too. For inspiration look at the archives of the audacity nyquist list at sourceforge. These would happen in the second half of the project after the basic upgrade.


VAMP support

Possible Mentors:

  • Chris Cannam

Description: Extend support for VAMP (http://www.vamp-plugins.org/) in Audacity.

VAMP is a powerful plug-in system for analysis of audio. It is used in the Sonic Visualiser audio analysis engine. Providing it in Audacity has opened the door to analysis based editing and effects, such as applying an effect where a particular analysis value is above some threshold. Audacity implements a simple interface to VAMP, and displays analysis tracks using the label track. There are many possibilities for extending this. Most of them involve extensions to the Audacity GUI.

Skills:

  • C++.
  • Developing on Linux and Windows.

Difficulty:

  • Moderate.

Early spinoffs from this work:

  • Sibilant extender/contractor by combining sibilant classifier with a stretch-where-marked effect.
  • For most projects it is a very good idea to discuss the project on audacity-devel mailing list before applying. With this one it is essential.


Intuitive cross-fading

Possible Mentors:

Description: One of the most common operations people want to do when mixing audio is to smoothly transition between two sound clips. This is commonly called a cross-fade. This operation is technically possible in Audacity now, but it is very clunky, requiring multiple steps and no editability short of undoing the actions and starting again. We are looking for someone to implement a clean, intuitive, nondestructive cross-fade for Audacity. Audacity already has all of the infrastructure necessary to support implementing this operation nondestructively and we already have a clear plan for how it should work. The following webpage has a mockup of what we think the GUI might look like:

http://limpet.net/mbrubeck/temp/cross-fade/ 

This feature, while seemingly small, would represent a huge boost in usability for Audacity. This feature is intimately related to several other UI enhancements that we have proposed: for example, one element of this proposed GUI is that clips "stick" to each other or "snap" into place when you push them together. Such a snap-to behavior would be great in several other circumstances, for example having a track stick to t=0, or to a point that lines up with another track.

Skills:

  • wxWidgets and C++

Difficulty:

  • Moderate.

Early spinoffs from this work:

  • Ability for all effects to be faded in/out automatically. This can avoid clicks in some circumstances.


More ideas

There are further ideas on our More GSoC Ideas page. Also see our Use Cases and Feature Requests pages (over 200 requests), which may suggest ideas for a project proposal.