Mixxx Development Blog

Mixxx with the Stanton SCS.3d and SCS.1m

2009-06-19T17:37:00.005+01:00

Sean Pappalardo's been busy again, this time working on support for the Stanton SCS.1m and improving our existing support for the SCS.3d. In this first video, Sean explains some of the neat features he's coded like fader-start, real-time feedback using the SCS.1m LED digit displays, and lots of other bells and whistles.

In this second video, Sean demonstrates some of the new features he's implemented since he made his original SCS.3d video, including the new vinyl platter mode and VU meters.

Our improved SCS.3d and SCS.1m support will be available for everyone to play with in our next beta. In the meantime, current hardware owners can still use their controllers with Mixxx 1.7.0 Beta1, but they'll have some extra to look forward to in our next release.

Speaking of which - Since our recent beta, your bug reports have provided us with important feedback that's helped us discover, fix, and prevent several problems. We've now identified a handful of remaining issues that we want to tackle, and once they're fixed, we'll either release another beta or a "release candidate". We've also completed a preliminary round of planning for Mixxx 1.8, but we'll save that for another blog post. Stay tuned!

Mixxx 1.7.0 Beta1 for Windows x64 Now Available!

2009-05-07T15:43:00.001+01:00

The Mixxx team is pleased to announce the availability of a 64-Bit version of Mixxx 1.7.0 Beta1 for Windows.

In a dazzling display of masochism and borderline insanity, Sean Pappalardo has been working hard over the last month or so to get Mixxx to run natively on 64-bit Windows. When asked why, he just mumbled, "full power...full power" over and over again as he rocked in his chair. Sean comes from the Commodore 64 programming days of yore when 64 KB of RAM and a 1 MHz CPU was all you had to work with, so he enjoys taking maximum advantage of the available hardware.

While 64-bit versions of Mixxx have been available on Linux for the past year, this is the first time it's been done on Windows.

Why was there no 64-bit version of Mixxx for Windows? As Sean found out, this was not simply a matter of recompiling Mixxx - all of Mixxx's dependencies had to be rebuilt as x64 binaries as well. This process brought numerous headaches and profanity-littered screams because Microsoft's Visual Studio is not always easy to deal with (especially when you're trying to force the free version to compile x64 binaries which involves a hack .) Fortunately a couple of the libraries that Mixxx depends on (libsndfile, FFTW) already had x64 binaries available for download, and for that we are very grateful. The good news is that, unless we decide they need upgrading, the dependencies don't have to be rebuilt in the future, so the hard part is done for now.

Mixxx is now the first and only known DJ software package that runs natively on 64-bit Windows, and this gives 64-bit Mixxx fans improved performance for free. A native 64-bit build also improves compatibility with ASIO devices on 64-bit Windows.

To take advantage of this, you need three things:

a 64-bit AMD or Intel processor (eg. AMD Athlon 64, AMD Phenom, Intel Core 2)
a 64-bit version of Windows (XP Professional x64, Vista x64, Server 2003 x64, etc.)
A copy of Mixxx x64 for Windows

Install and run as usual, and enjoy! Please let us know if you have any problems or questions.

Mixxx 1.7.0 Beta1 Released!

2009-04-23T10:00:00.002+01:00

The Mixxx development team is proud to announce the first beta of Mixxx 1.7.0. This latest release is the culmination of six months of work by over a dozen contributors, and contains several exciting new features as well as many bug fixes.

Some of the new changes in Mixxx 1.7.0 Beta1 that we'd like to highlight are:

Cue points are now saved in the library for each track, with "auto-recall" cue option added to preferences.
The default skin is now widescreen, and fits nicely on netbook sized screens.
Stereo master VU meter added.
MIDI overhaul:
- MIDI learning wizard
- MIDI mappings table editor
- Upgraded, faster mapping system
QtScript/JavaScript-based MIDI Scripting Environment - Code up complex behaviour for your MIDI controller without recompiling Mixxx!
MIDI output now fully supported on Windows, OS X, and Linux.
Added full support for the Stanton SCS.3d on all platforms.
Added Mixman DM2 mappings for Linux and OS X.
Vinyl Control:

Scratching responsiveness improved, with needle-skip prevention option added.
Signal quality indicators added to vinyl control preferences.

Merged the mixxx and mixxx-data packages for Ubuntu users into a single mixxx package.
Fixed about 40 bugs, including:

Browse mode no longer disappears in certain situations
Skin changing is now much faster
Tooltips now work again
Fixed rare instabilities caused by certain OGG and MP3 files
Minor improvements to the BPM detection
Fixed some OpenGL issues
Fixed a handful of obscure issues that may have prevented Mixxx from starting up on Windows
Play nicer with Ubuntu systems that are running PulseAudio

Aside from these more visible changes, there was significant work done on less visible parts of Mixxx. This includes many improvements to the organization and cleanliness of our source code, as well as a lot of work on features that didn't make it into the final 1.7.0. release. Improving the overall codebase is important for us because it makes it easier for new developers to contribute, and it was these new contributors who helped catalyze the overhaul of our MIDI system.

Back around December, we started toying around with the idea of something we called MIDI scripting. The idea of MIDI scripting is that having a small scripting engine sitting on top of our regular MIDI mappings would allow our users to code complex behaviour for their MIDI controllers using a JavaScript-like language. Soon after this idea hatched, we realized MIDI scripting would make it much easier for us to support new controllers in the future, and this attracted the attention of a handful of our developers.

Because we felt that both the long-term and short-term impact of implementing MIDI scripting would be very beneficial, several of our developers decided to shift their time away from other subprojects that they were working on (like effects, the new library, and looping) in order to complete the MIDI overhaul and scripting engine. When this work was nearing completion, we collectively felt that MIDI scripting support along with the slew of other improvements we made were significant enough to call this release 1.7.0. We're very excited about the possibilities that scripting opens up, and we hope to see our users come up with new, cool uses for it.

We'd also like to thank Stanton for their support during this development cycle, which allowed us to significantly accelerate the development of our MIDI scripting functionality. We're pleased to be the only cross-platform DJ software that fully supports the SCS.3d without the use of any extra software in the middle.

Lastly, if you encounter problems with the beta, please report them in our bug tracker! We hope you enjoy Mixxx 1.7.0 beta1, and we'll be working hard towards a final, stable release. Stay tuned.

Errata

The overhaul of our MIDI code included many changes to our MIDI mapping file format. Some of our old mappings were converted automatically by a script, but many required additional modifications by hand, which introduces the possibility of us having made errors. Due to the limited availability of hardware and free time within our development team, the MIDI mappings for some controllers have not been tested. If you have a controller that we provide a mapping for, please test it and report your results in our controller testing matrix.
MIDI Pitch messages are no longer processed internally and must be mapped to a script function. Fortunately script.pitch can be used very easily from your script.
M-Audio Xponent support has likely been broken. Support for it needs to be rewritten using scripting, but none of our developers have this device. (This is a great task for a user who wants to contribute to Mixxx! Come ask someone on IRC in #mixxx on Freenode about it.)
Windows: MIDI feedback on all but the first listed controller doesn't work with more than one connected. It's best to disconnect/remove all (real and virtual) devices except the one you're interested in working with.
Windows: You may need to tell Windows to send MIDI output to the correct device, especially if you hear random notes instead of see lights on your controller: Start→Settings→Control Panel→Classic View→Sounds and Audio Devices→Audio Tab, set “MIDI Music Playback” at the bottom to the device you're trying to use.
The use of multiple MIDI devices simultaneously is not yet supported.
For script developers:

The SelectNextTrack, SelectPrevTrack and LoadSelected controls do not work in the Browse view. See bug #342120.
The SelectNextTrack and SelectPrevTrack controls cause the GUI to freeze for a few seconds when you try to scroll down beyond the current page. See bug #361170.

Hercules releases GPL Linux MIDI drivers & Mixxx 1.6.1+Herc is released

2009-02-19T02:03:00.018Z

On Feb 16th, Hercules released GPL Linux MIDI drivers for their DJ Console / DJ Control series of MIDI input controllers ( Mk2, RMX, MP3 Control, DJ Control Steel ).

Mixxx is proud to support Hercules' great contribution by releasing Mixxx 1.6.1+Herc (Linux) and the +Herc MIDI mapping update packs (Windows & OSX). All are available for download now at http://mixxx.org/

Hercules users are encouraged to download these updates and visit the Mixxx Hercules documentation page at http://mixxx.org/hercules/.

Release Notes

1.6.1+Herc

This release is geared towards better support of Hercules devices only, it is functionally identical to 1.6.1.
Windows and OSX Hercules users should download the +Herc pack and read the docs at http://mixxx.org/hercules/.
Linux Hercules users should download & install the Hercules Linux MIDI drivers, then 1.6.1+Herc packages on this page and read the docs at http://mixxx.org/hercules/.
All Hercules users should read the docs and then look for help on the forums and IRC if they have issues.

Hercules DJ Console Mk1 users will have to wait until usbquirks is modified in the Linux kernel to remove the quirk for Mk1.

MIDI Scripting and the Stanton SCS.3d (Videos)

2009-02-09T16:25:00.008Z

One of Mixxx's newer developers, Sean Pappalardo (DJ Pegasus), has been hacking away at MIDI scripting for the past few months so that we can fully support more advanced MIDI controllers. One of the new controllers scripting will allow us to support is Stanton's SCS.3d (aka "DaScratch").

The Stanton SCS.3d replaces conventional knobs, buttons and sliders found on other MIDI controllers with touch-sensitive surfaces laid out in a DJ-friendly format. It's compact, rugged, light-weight, and best of all, reliable, since there are almost no moving parts to break. The large central circular area is where all the magic happens as it can be configured to serve multiple purposes (jog dial/vinyl emulation, three sliders, or 9 buttons) depending on the control needs of the software.

Sean demonstrating the SCS.3d with Mixxx 1.6.2

Mixxx's previous MIDI system only allowed you to map one MIDI control to one property and provided no means of feedback or otherwise sending commands to the device. However, controllers like the SCS.3d are of limited use without being able to illuminate LEDs and toggle various modes, since there would be no physical indicators.

Stanton gets around this by offering a free middleware solution called "DaRouter" which essentially acts as a MIDI translation bridge between your DJ software and the SCS.3d. However, it is difficult to get feedback to the controller from your DJ software, and your ability to customize the device's behaviour is limited. Additionally, this middleware solution is not available for Linux.

Enter Mixxx's new MIDI Scripting Engine.

After scratching our heads for some time, we conjured up and coded a system that allows DJs to link hardware MIDI controls with custom script functions. These scripts are written in QtScript, which is an easy language that's almost identical to JavaScript. Scripts can contain functions that can affect any number of Mixxx controls and also send feedback to a hardware MIDI device, freeing Mixxx from a one-to-one mapping ideology. These user-created scripts can then do anything desired with the MIDI event data such as have a single controller button simultaneously affect two or more Mixxx properties, adjust incoming control values to work better with Mixxx (scratching,) display a complex LED sequence, or even send messages to text displays on the controller.

This approach provides a number of key benefits:

Script functions are evaluated at run time and and can access or modify Mixxx's internal properties.
QtScript brings all of the advantages of a full scripting language. For example, functions can use variables, allowing a single piece of code to be used for multiple cases and to remember states between invocations (this is how we implement mode and deck switching).
Functions can send any MIDI messages they like including SYStem EXclusive messages, needed for advanced controllers like the SCS series for mode changes and text displays.
Functions can be connected to Mixxx properties so that when the property changes, the function is called with the new value, allowing automatic controller response.
DJs can customize the script functions to suit their particular work flow and desires without compiling anything.
Support for complex controllers can be added to Mixxx at any time between releases by anyone since no compilation is needed!
No middleware is needed to use advanced controllers like the SCS.3d with Mixxx
Our MIDI scripting system is platform-independent, which makes it available to Windows, Mac OS X, and Linux users!

Our new MIDI scripting engine is going to be the biggest new feature in Mixxx 1.6.2, and we're currently polishing it up along with some of our other MIDI code. We hope to have a beta release out within the next month or two for our DJs to play with.

Lastly, we'd like to thank Stanton for their gracious support and cooperation. We think the SCS.3d is going to be a great device for Mixxx users in the future!

Looking for a Community Coordinator

2008-12-17T23:46:00.002Z

Are you a creative Mixxx enthusiast?
Would you like volunteer with the project, but don't know how to code?
If so, we might have found the role for you - We are officially looking for a Mixxx Community Coordinator.

As the Mixxx community grows, we're finding that we're spending more and more time on administrative tasks and less time writing code. We've got cool ideas for stuff to do with our community, but we don't have time to do them and keep pushing development forwards at the same time. A community coordinator will help fill a growing niche in our development team and will be a great benefit to the project.

Our community coordinator will have many responsibilities, including moderating the forums, writing blog and news posts, and will also hold the cherished title of Mixxx Chocolatier*. We're looking for a dynamic, enthusiastic individual with a passion for DJing (and excellent English language skills) to fill this position. Any experience with forums and HTML is a plus.

If you think you'd be a good candidate and you'd like to be our community coordinator, please contact Adam or Albert and tell us a bit about yourself. Due to the importance of the responsibilities involved, we'll be following up with interviews for potential candidates.

As Mixxx continues to grow, more opportunities for more volunteers to help out without coding will continue to arise. We've seen tremendous growth since our 1.6.0 release, and there's no signs of slowing down. Getting involved with an open source project also looks good on your resumé or CV, and it can help demonstrate the diversity and flexibility of your background. 2009 will be a great year for Mixxx, and we're looking forward to hearing from interested volunteers!

* More on the chocolatier front will come as we fill this position.

Effects Progress

2008-11-24T07:05:00.005Z

Since the 1.6.1 release, we've been hard at work integrating several new features that have been in the works for a while.

In our last user survey, many people told us that Mixxx needed some effects besides the flanger. In response to your feedback, we had Pawel Bartkiewicz work on LADSPA integration through Google Summer of Code in 2007. LADSPA is a terribly misleading acronym for "Linux Audio Developers Simple Plugin API". As it turns out, LADSPA isn't just for Linux - it's a cross-platform effects plugin framework, and that made it the natural choice for us. Pawel did great work last Summer, but it came in middle of our 1.6.0 development cycle and in order to properly integrate his work into Mixxx, several other tasks needed to be completed first.

One of these more noticeable tasks has been to create a new tabbed view, where both the library and effects pane can be managed.

With the new reverb and "DJFlanger" effects, you can add some interesting flavour to your mixes.

The screenshot above shows the effects panel inside the new tabbed view. It also shows several of the effects that we're going to bundle, on the left. The tabbed view will also give us a compact place to expand Mixxx's user interface in the future.

If you look at the screenshot closely, you can spot some rough edges that we're trying to fix before our next major release. The main tasks that remain are bug fixing, polishing, and updating our distribution stuff (installers, packaging scripts, etc.).

For Windows and OS X users hoping for VST support, we think it should be possible via Audacity's awesome VST enabler. The VST enabler should allow us to load VST plugins, but to my knowledge, nobody's tested it yet. The reason we can't build native VST support directly into Mixxx is because of Steinberg's restrictive license on their VST software development kit.

That's all for now! We're going to keep hacking away at LADSPA and the rest of the new features we're working on, and hopefully we'll have something out the door before the end of the year.

Mixxx 1.6.1 Released!

2008-09-27T00:27:00.002+01:00

Hot off the heels of our last release comes Mixxx 1.6.1, bringing a handful of new features and bug fixes.

Download Here

Some of the more important changes are:

The waveform view now zooms instead of speeding up when the pitch is adjusted. This allows the beat ticks to align when songs are beatmatched, and was a feature request we heard many times after the 1.6.0 release.
FLAC support for Windows users! (Another much requested feature, and you can thank Michael Pujos for his hard work on this.)
Fixed a problem where the waveform view went unresponsive (thanks to Mark Glines for the patch)
Properly read artist and title names from FLAC files (another one from Mark)
Fixed drag-and-drop on Windows with the "Simple" display mode.
Fixed a Hercules RMX problem with its MIDI mapping.
Fix for songs with short artist names.

We've also had some mild success with M4A/AAC support, but it's still going to be a while before that feature makes it into a release unfortunately. We're also still working on our OS X 10.4 (Intel) package still, but we do have an unsupported OS X 10.5 package for PPC available for download here.

Mixxx 1.6.0 Released!

2008-08-06T12:00:00.005+01:00

The Mixxx team is proud to announce the final release of Mixxx 1.6.0!

Mixxx 1.6.0 represents over a year's worth of hard work from our growing development team. The development of 1.6.0 was been driven by continuous feedback from our users, the bulk of which began in May 2007 with our popular user survey. Since then, we've taken the features that people wanted the most and focused every effort on developing them. Needless to say, 1.6.0 is light-years ahead of 1.5.0, and our community's continued appreciation for Mixxx has served as a strong motivator for us throughout its development.

We've also relaunched our website with a fresh coat of paint. Clicking the thumbnail above will take you to the new site.

Mixxx 1.6.0 is now available on our downloads page.

We'd like to thank both Hercules and Echo Audio for supporting Mixxx's development. Hercules' MK2 and RMX controllers are excellent, and Echo makes fantastic professional-grade soundcards (and we mean it).

If you'd like to come hang out with some of the Mixxx developers and fellow users, we're having a meetup at the Linuxcaffe in Toronto on Friday, August 8th from 7 PM to 11 ish. Come check it out!

Before getting to the changelog, I'd like to mention one thing - A big change we've made is that Mixxx 1.6.0 is built on the Qt 4 platform instead of Qt 3. Porting Mixxx to Qt 4 took a massive effort from many developers, and was important to modernize Mixxx's look and feel, as well as ensure that Mixxx's codebase doesn't become obsolete. We've made many technical improvements inside Mixxx in order to allow the project to grow well into the future. Mixxx is now a much more mature open source project than it was a year ago, and there's no signs of us slowing down.

Since Mixxx 1.5.0 was released (March 4th, 2007), the following changes have been made:

New MIDI mappings for Tascam US-428, M-Audio X-Session Pro, Evolution X-Session, FaderFox DJ2, and the M-Audio Torq Xponent, Vestax VCI-100, Akai MPD24, Behringer BCD3000 (including LEDs), Numark Total Control
Many Hercules MK2 improvements
Support for the Hercules DJ Console RMX
Support for the Hercules DJ Console Mac Edition
Slick sliding VU meter peaks - Screenshots don't do this justice (download it and check it out).
Added the new Natt skin, from Natt from the forums.
Completely rewritten waveform view by Russell Ryan through Google Summer of Code. This will provide better performance for some users.
Some very under-the-hood improvements that should fix the odd crash-at-startup and improve performance.
Fixed keyboard cue keys to use whatever cue behaviour is selected in the preferences.
MP3 parsing fixes for files with cover art (fixes blips at the start of some songs)
OGG parsing improvements, fixes some library scanning problems
Fixed OGG playback on Intel OS X machines
Completed drag-and-drop support in the library. You can now import tracks to the library by drag-and-dropping a track from outside Mixxx onto the library view. You can also reorder tracks in a playlist or the library.
Option to disable the BPM detection.
Added BPM reading from MP3/OGG files which have it embedded in them (ID3), one of several enhancements by Martin Sakmar
Various accuracy improvements to the BPM detection
Improvements to the vinyl emulation and pitch-independent time stretch sound quality
Wave recording support
Vinyl control with support for Serato, Traktor, and FinalScratch vinyl, as well as Serato CD.
Added support for multiple inputs on a single soundcard for vinyl control
Build flags are now cached automatically
Improved flanger effect, thanks to Enry
Configurable cue behaviour, which now defaults to CDJ-style cueing. (Thanks to Tom Care)
Enabled realtime priority with ALSA, improves performance with Linux RT kernels.
FLAC support for Linux and OS X users (much requested)
Tons and tons of bug fixes.
Fixed crashes due to vinyl emulation mode
Improved compatibility with JACK (some users were experiencing choppiness)
Players should now only pull from the play queue if in NEXT mode
Search functionality:
o Search box now selects all text when clicked (easier to make a new search now)
o When the search box is cleared, the library view will scroll back to it's previous position.
o Search now properly filters directories out
Library stuff:
o Double-clicking on a song now sends the song to the first stopped player.
o Right-click menu cleaned up, much nicer now
o Library directory rescans on startup when it's been modified (*doesn't work when subdirectories are modified yet)
o Library view now shows directories first
o Columns in the library view are proportioned intelligently now
o Renamed the "Playlist" menu to "Library"
o Added "Rescan Library" menu item.
o Can select multiple songs (hold shift) and send them to the play queue or a playlist
Playlist support:
o Can create, import, delete, and rename playlists
o Added "Playlists" to library drop-down box
+ Can right-click to send a playlist to the play queue.
Fixed some bugs in the track properties dialog, and set default values
Fixed a soundcard channel selection bug when the second device had more channels than the first.
Added BPM Schemes (need to make some presets still)
Minor speed optimization
OS X/Leopard package for Intel users!
A few build system (dependency checking) fixes
MIDI LED control on Linux
A few MIDI tweaks here and there
Right-clicking on a knob/slider no longer moves with your mouse (it just centers the value)
Using your mouse's scroll wheel now changes the values of sliders and knobs (this is cool for laptop users with the little scroll bar at the side of their trackpads)
DirectSound is now the default API on Windows
ALSA Sequencer MIDI support courtesy of Cedric Gestes
A couple of MIDI bug fixes (knobs now center properly, thanks to Sacha Berger)
Added support for 14-bit MIDI pitch wheel controllers (thanks to Adam Sugerman)
Hercules support on Linux improved (jog wheels work again)
Big stability improvements
Multiple soundcards can now be used for output (master/headphones), in case you don't have a soundcard with 4 outputs on it.
Adam's wicked colour scheme support for skins
Can now change skins without restarting Mixxx (more hard work from Adam)
Channel VU meters are now pre-fader
VU meters are now much more smooth
Added clipping indicators (courtesy of John Sully)
Higher quality EQs and other sound quality improvements (also from John Sully)
Adjustable EQ shelves
New MIDI mapping format now in XML, supports controlling LEDs
Better Hercules support on Windows and Linux
New BPM detection algorithm (Micah Lee/GSoC 2007)
New media library (Nathan Prado/GSoC 2007)
LADSPA effects support (not yet enabled - Pawel Bartkiewicz/GSoC 2007)
BPM Tap tempo
Ported to Qt 4
Moved build system to SCONS
Redesigned preferences dialogs
Rewritten audio core (Albert)
Vinyl control support for Serato, Traktor Scratch, and FinalScratch (FS needs work, but the others are good)
Software preamp for vinyl control (can use turntables without a preamp)
Track info editor (double-click in library)
New library browse mode (CTAF)
Starts in fullscreen mode if launched with the -f flag.
Several MP3 decoder performance and stability improvements (John Sully)
Support for merengue
Reorganized "File" menu
NEXT mode now works as expected (plays the next track in the table)
Lots of little OS X improvements
Improved consistency of fullscreen mode
Customizable constant power crossfader curve
Slow fade and fast cut crossfader curves
Play queue, for creating an on-the-fly playlist
Revamped playlist interface, editing
Reasonably intelligent library rescanning

Once again, Mixxx 1.6.0 can be downloaded for free from our downloads page.

Mixxx Meetup – Friday, August 8th 2008 7pm @ Linux Caffe Toronto

2008-08-02T15:00:00.001+01:00

Mixxxers, all your hard work is about to pay off, we're about to release our first major update in more then a year and that means it's party time.

Join us at the Linux Caffe in Toronto as we meet, eat, and scratch out some beats to celebrate the newest release of the world's best free DJ software: Mixxx 1.6.0!

Date: Friday August 8^th 2008 - 7pm till they kick us out (~11pm)

Location[map]: Linux Caffe is at 326 Harbord Street, Toronto, ON, M6G 3A4 (a block south of Cristie Subway Station)

Mixxx 1.6.0 Release Code-a-thon

2008-07-25T16:09:00.002+01:00

It's hard to believe it's been over a year since the release of Mixxx 1.5.0, our last stable release. However, we're pleased to say that we're now nearly ready to bring 1.6.0 out of beta.

As part of the final push to get the release done, we're planning a whole day coding/fixing/testing session next Tuesday (the 29th). Most of the development team will be on our IRC channel (#mixxx on irc.freenode.net) and everyone is invited to come and join us. Whether you want to help write code, help test the release as it comes together, dj up some tunes for the development team or simply come and watch, everyone is welcome and there will be plenty to do, even for non-technical people. Things should start around 10am in Europe and run through to the evening in the Americas.

Look forward to seeing you there,

Adam

Mixxx 1.6.0 Beta 4 Released!

2008-07-17T18:17:00.002+01:00

The Mixxx development team is proud to announce the fourth beta of Mixxx 1.6.0, the premiere open source DJ software. (Download!)

Our last two months of development have been spent polishing 1.6.0 and fixing as many remaining bugs as we could find. We've tackled numerous performance issues and fixed many bugs people have reported.

Mixxx 1.6.0 has been in development for almost a year now, and earlier this month we decided to start wrapping up development. Beta 4 will be our last beta release, and we're hoping to release 1.6.0 final within the next couple of weeks. The 1.6.0 release will also mark a change in our development process, so that we can both improve the quality of new features and ensure more frequent releases. I'd like to write more on this after the 1.6.0 release to help give Mixxx fans some insight into how our development process works.

Back to Beta 4 in the meantime though - Here's our list of improvements since Beta 3:

Completely rewritten waveform view by Russell Ryan through Google Summer of Code. This will provide better performance for some users.
Slick sliding VU meter peaks - Screenshots don't do this justice (download it and check it out).
Added the new Natt skin, from Natt from the forums.
Fixed some play queue bugs.
Some very under-the-hood improvements that should fix the odd crash-at-startup and improve performance.
Fixed keyboard cue keys to use whatever cue behaviour is selected in the preferences.
MP3 parsing fixes for files with cover art (fixes blips at the start of some songs)
OGG parsing improvements, fixes some library scanning problems
Fixed OGG playback on Intel OS X machines
Completed drag-and-drop support in the library. You can now import tracks to the library by drag-and-dropping a track from outside Mixxx onto the library view. You can also reorder tracks in a playlist or the library.
Added support for the Vestax VCI-100
Hercules MK2 improvements
Disabling the BPM detection works as advertised now.
Improved vinyl control behaviour near the start of the vinyl.

As with our previous betas, please report any bugs you find.

We plan to have the 1.6.0 final out within the next few weeks, as mentioned earlier. In the meantime, stay tuned and download Mixxx 1.6.0 Beta 4 to tide you over!