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Beat Maker: The drum loop maker written with Qt

Beat Maker is my “pet project” with Allyson Soares at INdT.

It is, basically, a drum loop emulator to be used by musicians during practicing sessions.

You just need to select the samples, define a BPM value and listen to the rhythm ;)

If you can’t wait for the official release at Ovi Store, you can try the beta version for n900 devices.

Remember: it’s a beta version of an open source software. The code can be found linked to my gitorious account.

The technical point of view:

I’m a little bit disappointed with phonon. After a long discussion I’ve realized that phonon could not be used on Beat Maker.

At this time I’m using an approach suggested by Adriano Rezende: play the sound using pulseaudio’s API. I know, it’s not portable. But hey, my target is N900 devices and it worked pretty well at the time.
However, it doesn’t scale. So, now, I’m working on a kind of “in-app-mixer”, which should solve this problem.

There is another problem, related to QTimer. Qt can’t guarantee the timing between the beats using QTimer events. Especially when you generate mouse events. Anyway, the mixer controller loop should solve this as well.

Big thanks to Adriano for the tips, and Allyson who made the excellent UI design.

I hope you enjoy it.
Suggestions are welcome =)

ps.: youtube video bellow


  1. 2beers

    great app . congrats. so are you looking for a replacement to pulseaudio ? I’m also interested in something similar .

    Posted on 14-Oct-10 at 10:24 pm | Permalink
  2. Kenneth Christiansen

    Very nice Danilo! Looks darn nice!

    Shouldn’t the name of the app (in the title bar) be “Beat Maker” and not “beatmaker”?

    Posted on 14-Oct-10 at 10:25 pm | Permalink
  3. @Kenneth: Yes.. I’m patching it now.. Thanks ;)

    @2beers: Well, what I’m trying to do is mixing thing on application side, and send just one stream to pulseaudio. But it’s still a working in progress. I will let you know when I finish it.

    Posted on 14-Oct-10 at 10:29 pm | Permalink
  4. Tumleh

    Thanks for the current version of Beat Maker, it is really a great application, and I just have posted it in the blog

    Please note that this post is readable for you officially only on Oct 19, 2010.

    Posted on 15-Oct-10 at 7:32 am | Permalink
  5. zifis

    Great app! thank you so much :)

    Posted on 15-Oct-10 at 11:08 am | Permalink
  6. @tumleh: Ow, cool! I’m excited to see it there =)

    @zifis: Thanks! =)

    Posted on 15-Oct-10 at 11:35 am | Permalink
  7. sparkyERTW

    Awesome, Danilo, just awesome. I’ll be downloading this immediately. I’ll be getting in touch with you; if you’d like any help testing or bug fixing (hell, I’d even help with documentation!), I’d be happy to lend a hand.

    Also, let Allyson know I love the interface. I’ll still trying to get the hang of mobile UI design (I’m used to designing for the desktop), and this is quite possibly one of the simplest and most elegant designs I’ve seen.

    Posted on 15-Oct-10 at 11:38 am | Permalink
  8. Adam

    Surely the BPM is wrong? It was set to 266 bpm at the end of the video, but in reality it sounded more like 130-140 bpm. Can this be scaled to real bpm, or is it limited by the phone?

    Posted on 15-Oct-10 at 12:07 pm | Permalink
  9. @Adam,

    You’re right. The BPM is wrong… Will be fixed soon. Thanks for the warning ;)

    Posted on 15-Oct-10 at 12:29 pm | Permalink
  10. Adam

    Thanks for the quick reply! I’ll be playing with this app as soon as I leave the office ;)

    Posted on 15-Oct-10 at 12:44 pm | Permalink
  11. Very nice application! Just downloading now :)
    Congratulations to you and the others.

    Posted on 15-Oct-10 at 3:40 pm | Permalink
  12. That’s is what happening when a company allow its employees to work on them personal projects in working time. Great job!

    Posted on 15-Oct-10 at 8:37 pm | Permalink
  13. KevinB

    That’s awesome dude, really!
    Congrats… Do you have any idea to improve it?
    One idea is, being able to make a more precise pattern beat with “Additive rhythm” so we can make some jazzy groovy beat :D!

    Congrats again dude, very good idea!

    Posted on 17-Oct-10 at 8:39 am | Permalink
  14. sephlee

    Nice One! I am a jazz drummer… I will try..

    Posted on 18-Oct-10 at 11:12 am | Permalink
  15. Fuck yeah, Danilo! I use Audacity to generate stupid click tracks before I go running (yes.) but your beat track thing sounds more fun, really neat application :-)

    Posted on 18-Oct-10 at 9:31 pm | Permalink
  16. Walther

    Awesome. This is way better than a metronome for my piano practice :)

    Posted on 19-Oct-10 at 7:40 am | Permalink
  17. mr id

    Nice job :)

    Look forward to seeing it improve. I’m currently building a multitrack recorder fro the n900 so it will be great to have a working sample looper on the platform.

    I’m guessing it wouldn’t take much to extend your code to let users import their own samples and create different kits?

    Would also like to see a longer timeline, the ability to ‘record’ the playback to file (.wav).

    But hey, no rush! I know how development works.

    I see the code to date is GPL3 are you intending to maintain it under this license even after it makes it to the Ovi store?

    Posted on 19-Oct-10 at 8:11 am | Permalink
  18. mr id

    Sorry, shoudl have been LGPL 2.1 (not GPL3) looking at too much source code today.

    Posted on 19-Oct-10 at 11:09 am | Permalink
  19. The idea is to keep the code under GPL license. Even if it goes to ovi.

    “I’m guessing it wouldn’t take much to extend your code to let users import their own samples and create different kits?” is a future feature =)
    For now, I need to fix the mixer… It’s a major/blocker issue before releasing it on Ovi.

    I’m refactoring the code too… It was suppose to be a toy, but after 632 downloads we changed our idea =)

    Posted on 19-Oct-10 at 11:42 am | Permalink
  20. Magnus

    I’ll check this out. My usage is to learn patterns to play on my doumbek (derbouka/tabla), so, yes, the ability to import such sounds would be great!

    Posted on 21-Oct-10 at 1:58 am | Permalink
  21. ksm

    thank you for this brilliant app. If you could change the beet number from 8 : ie to 12 , it would please flamenco musicians greatly.

    Posted on 14-Nov-10 at 5:23 am | Permalink
  22. very good information, ill be sure to bookmark this. Thank you!

    Posted on 15-Jan-11 at 7:57 am | Permalink
  23. This is great for record producers. I will tell others about the quality of your beat maker online tips.


    Posted on 06-Feb-11 at 1:37 pm | Permalink
  24. Corey

    hey Danilo
    awesome app it is so cool problem is I don’t have a phone and I was just wondering if you could write a version that would run on Microsoft windows coz that would be so cool to play around with and use in drum lessons etc.
    Thanks Corey

    Posted on 25-Oct-11 at 1:40 am | Permalink
  25. I believe I can’t, sorry. Since it depends on pulseaudio libraries I don’t think you can run it on windows =(

    Posted on 09-Jan-13 at 12:39 pm | Permalink

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