Jamming to MP3 audio with Rakarrack

  • zumajim

    zumajim - 2011-07-06

    I don't know if this is even possible but would be a dream come true: I want to be to play along with MP3 jam tracks through Rakarrack. I have Rakarrack/jackd working fine on my Fedora 15 system but can't figure out how to mix Rakarrack's output with an MP3 audio stream, if that's even possible. Can I feed Rakarrack's output to a multimedia player (e.g. XMMS)? Clearly, I'm a Linux audio noob, but would like to hear your ideas. Thanks!

  • Transmogrifox

    Transmogrifox - 2011-07-07

    This is actually pretty simple using jack.  You will want to use a jack routing program like qjackctl or patchage.

    From there you patch Rakarrack to System Outputs, and also patch media player (audacious has a jack output plugin) to the same output.

    IIRC Totem automatically connects itself to system outputs so you don't have to manually route it, so try this:

    Open an mp3 in Totem (with jack active). 
    Open Rakarrack.
    Play to the music. 

    Use the volume controls on the media player and/or on Rakarrack to help adjust levels.

    There are also mixer programs for jack to do this sort of thing.  Search your package manager for jack mixers and see what you come up with. 

    Anyway, I don't have much for a step-by-step for you at the moment, but I hope this is encouragement that you can easily do what you're asking.

  • Transmogrifox

    Transmogrifox - 2011-07-07

    Just an extra:  I often use Rakarrack to process audio.  There are some stereo imaging effects and EQ that can make music sound very alive if adjusted properly.  I use Audacious, and just route Audacious' output into Rakarrack.

    To play along with an mp3, all I would have to do is route Audacious to system output instead.

  • zumajim

    zumajim - 2011-07-08

    Thanks, transmogrifox. As badly as I want to try out your suggestion, something has recently broken my jackd setup. In qjackctl, I can no longer see the system output for the speakers (Writable Clients/Input Ports tab). This is very frustrating since I saw them before and was able to patch Rakarrack to them. I don't know what changed other than a round of Fedora updates, none of which seem to have anything to do related to audio. I'll keep beating on qjackctl and see if I can fix, but for now, there's nothing to output my audio to.

  • zumajim

    zumajim - 2011-07-21

    Progress report: Finally got it all working! For whatever reason (probably a recent patch of jackd), Qjackctl is now listing the system outputs again, so I can route Rakarrack once more. Plus, I discovered the qmmp player, which supports jackd. Although qmmp doesn't play MP3s, I was able to convert my jam tracks to OGG. This is working pretty well and I'm happily jamming along to my heart's and finger's content. It's really fun.

    I'd still like to find a multimedia player that supports jackd and MP3 as qmmp seems to have memory leak and locks up after an hour or so. (Totem doesn't seem to want to play with jack on my system.)  Also, if qmmp isn't actively playing a stream, it doesn't show up as an output source in qjackctl, but that's a minor nit.

    FYI, I'm playing my stock Fender Strat (with its noisy single coil pickups) through an Alesis GuitarLink USB cable. This device shows up as "USB PNP Device" in qjackctl and must be plugged in before starting jackd or it never gets found.

    Thanks for all your help!

  • Josep Andreu

    Josep Andreu - 2011-07-22


    99% of media players support jack,  personally I use aqualung …. about to reproduce MP3 .. all the media players of course can reproduce MP3 .. what you need  is the non-free codecs that are available for all the distros.

    Try to use another instance of rakarrack to listen the music … they are a special preset created to listen music called "Music" I think is on the third bank … :-) only you need to do the connections in qjackctl with the second instance.



Log in to post a comment.