Last night I did a bit of experimenting with Dj mixing programs that can use Jack as an audio server. I am on an Ubuntu Studio machine.
The reason why I only tested programs that use Jack is because of flexibility. With Jack, I can reroute input and output signals to other pieces of software for additional mixing or processing.
The three programs I auditioned are:
1) Mixxx (2 channel mixing program, came installed with Ubuntu Studio)
2) DJPlay (2 channel "Dual CD" style mixing program, was in Synaptic repository).
3) Terminator X (Multi channel effects processing mixing program, came installed with Ubuntu Studio).
Anyway, these are my findings:
Last night I ran into a few hickups. I am right now trying out some DJ mixing programs and I previewed three of them (the ones that support Jack). Here are my findings:
1) Mixxx: This is a 2 source mixing program. Thus far my favorite of the bunch, BUT it is only working with ALSA right now and not Jack. The big stand out is Tempo Control (That is a DJ term. Part of DJ mixing requires a way to speed up or slow down songs. Traditionally that was done by a pitch control. The problem with pitch is that not only does it raise or lower the speed, it also affects the pitch of the recording. That isn't good. Tempo control on the other hand allows you to change the speed without altering the playing pitch. THAT is a much more desired trait because you don't end up with chipmunks or monsters for the vocals as traditionally would be the case with old analog equipment). Another standout is that it has an over/under Waveform display (this is the thing I needed OpenGL for). Having a visual waveform is a guide in lining up the peaks in the music to match the beat. Having the displays for both mixing channels over and under helps to line up beats both visually and through your hears. Output control is somewhat limited to two channels (and headphone) right now... but then again, I have not seen it work with Jack to really make an evaluation here.
2) DJ Play: Like Mixx, this is also a 2 source mixing program. Only option is to use Jack. A really nice program and it has quite a few different options for outputs. DJ Play can even hook up to an outside (physical) mixer. The downside is that it is a multiple window program and it causes A LOT of XRuns. (I don't know what XRuns really are, but I know it isn't a good thing). Audio quality is OK, but not as good as the other two programs. The xruns cause some skipping too. Another bad thing is the the program doesn't offer "Master Tempo". It has waveform display but it is very tiny.
3) TerminatorX: This is a multiple channel mixing program that has a very realistic scratch effect, it offers full effect procession support. It loads files, so loading is longer than the other two programs. However, the program causes almost NO X-Runs and has a really really good sound quality. BIG waveform display all on top of each other. It is LADSPA (plug-in) ready and has a whole slew of effects that can process the signal. You can have many input sources as well and not just two like with Mixxx or DJ Play. However, there are four huge problems: 1) No tempo control 2) No FF, REW, search, cue or looping functions 3) Very limited mixing controls. 4) Cannot redirect outputs to another mixer (only has two channel output with NO monitoring). And yes, I have tried to open up multiple instances of Terminator X. Jack will not let you. I guess they figured that if you can open several mixing sources within the program that having multiple instances of the program isn't necessary. But without a way to cue up (via headphones), I can't see it as a viable mixing tool.
I believe all three progams can use a supported MIdi controller for external control, but I have not tested any of those functions.
In summary, l I find this as a huge bummer! Out of the three graphical DJ programs meant to run on Jack, none really fit the bill for it's intended purpose.
These are my thoughts: If I could take the intuitive display and function of Mixxx, marry that with DJPlay's outstanding output configuration, AND marry that with the scratching and fantastic sound quality of Terminator X, I would have the perfect DJ mixing program!
Mixx comes the closest though. I just have to find a way to get Jack working with it to fully evaluate it. However, support for this program is VERY slow going. I reported my problem on the forum site 3 days ago and still I have yet to receive an answer.
I think the TerminatorX project is the most ambitious and if that program had master tempo, better transport controls, and better output routing, it would smear the board with anything that is out there both Open Source (Free) or Commercial.
Thanx for looking in and reading
.Geo
