• Posts
  • RSS
  • ◂◂RSS
  • Contact

  • Goodbye ChucK; hello straight C with JACK

    May 1st, 2010
    looper, music, tech
    The chuck-using looper software was being too annoying. I couldn't figure out why latency was being slightly off and variable between runs, I couldn't figure out how to get it to run realtime, and chuck kept crashing when I went to record long loops, giving:
    subgraph starting at RtApiJack timed out (subgraph_wait_fd=9, status = 0, state = Running, pollret = 0 revents = 0x0)
    I decided to have a look at writing this in straight C against the JACK api. Which seems to have worked quite well. It wasn't that much work, and now I know exactly what's going on. Chuck was good for prototyping, and really easy to get started with, but I have a lot more trust in this new version. One downside is that unless OSX has /dev/input/mouse then this is linux only. Which is sad. If there's an easy fast way to get mouse events on OSX I could add it.

    So. This requires at leas the following:

    $ sudo apt-get install jackd libjack-dev
    $ gcc -std=c99 -o looper_sync -ljack -lpthread -lrt looper_sync.c
    $ sudo chmod ugo+r /dev/input/mouse*
    $ jackd -d alsa -p 256 &
    $ ./looper_sync
    Unfortunately, while I was testing this one last time before writing it up, I managed to get the exact same "subgraph timed out" error in the C version that I'd gotten in the chuck version. I don't get it as easily in the new version; sometimes I can record three full length loops and not get it. Perhaps, though, this error means I'm trying to do too much work on one processing cycle? I need to look at it more. On my desktop it runs great, so I'm thinking it has to do with the eeepc being substantially less powerful.

    Comment via: facebook

    Recent posts on blogs I like:

    Be less scared of overconfidence

    deferring to markets • deferring to experts • deferring to low-information heuristics • why they fail • blindness to outliers • what to do instead

    via benkuhn.net November 30, 2022

    Corncob Dolls

    I went to a farm and at the farm I got to see a corncrib and the corn that had fell out of the corncrib that no one wanted I got to use my fingers to take off the corn kernels and once the cobs were empty I put them in a bag and then once I got back to the…

    via Anna Wise's Blog Posts November 7, 2022

    Light Switch

    When I got my loft bed it was just so annoying every morning to have to get out of bed, climb down the ladder, turn the light on, and climb back up, just so I could see stuff. I decided to make a string for my light switch because I really wanted to be abl…

    via Lily Wise's Blog Posts November 7, 2022

    more     (via openring)


  • Posts
  • RSS
  • ◂◂RSS
  • Contact