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Re: KX mini manual

Posted: Fri Apr 19, 2013 2:47 am
by ToddMWorth
danboid wrote:Anyone tried this stuff with Cadence? What for?
Yeh I've done this a bunch. Our most common application so far is this:

My mates are sitting in the home theater (where I am now) and playing oldschool arcade games on the big screen using a cool emulator called mednafen which just so happens to support jack (why gamers want JACK, I do not know, but I'm glad!). There are cool bleepy noises everywhere. Here, I run the Net backend (no additional configuration required, provided that your network supports broadcast packets, which it should, and probably already does), and alsa_out provides monitoring via the local soundcard, so that the players can hear the game.

Myself and another producer are sitting in the studio. In there, I've run `jack_load netmanager`, to load the jack module to listen for a network connection from the slave. This makes a JACK client magically appear in Claudia (or whatever patchbay you use) which has outputs on it and they are carrying the sound from the games played in the home theater. Sample, slice, loop, go crazy! :D

Lots of fun :D

Re: KX mini manual

Posted: Fri Apr 19, 2013 6:38 am
by danboid
Hi Todd!

Thanks for filling us in there - its good to know someone has tried Cadence's netjack support and it works!

As you say, it is crazy that an emulator should support JACK when we have apps like LMMS and Skype that don't and really should!

Re: KX mini manual

Posted: Fri Apr 19, 2013 7:14 am
by danboid
I have no real interest in LMMS until it acquires what I deem as basic features - stuff like undo and non 4/4 time signatures but thanks for pointing that out F!

Re: KX mini manual

Posted: Fri Apr 19, 2013 10:14 am
by danboid
Ye holy JACK configuration chapter has arrived!

http://www.wiki.linuxmusicians.com/doku ... figuration

I was considering doing another chapter on JACK but now I'm thinking I've just about covered everything a newb would need to know to get going. If they need further help they're best referring to the in depth help on the wiki or asking on here.

That doesn't mean the manual is finished though. We still need to cover Claudia, LADISH studios, basic package management and installing the GFX drivers etc yet.

Re: KX mini manual

Posted: Fri Apr 19, 2013 11:02 am
by wolftune
danboid wrote:I have no real interest in LMMS until it acquires what I deem as basic features - stuff like undo and non 4/4 time signatures but thanks for pointing that out F!
Undo is absolutely a must. Otherwise, I love, Dan, how you consider non-4/4 time a "basic feature". I acknowledge that there is a use for something that is 4/4-only but I am still appalled at the entire idea that these tools force music to fit certain boxes like that.

At any rate, I did not make any edits this time to the chapter. I do want to just add that I want to see a section about how to set the Extra Latency, at least with links (such as to the Audacity tutorial's nice documentation on this). Setting that is valuable.

Also, Hardware Aliases should be on (as it is in the screenshot). Perhaps if we can make sure this is done by default in KXStudio, then there's no need to document it otherwise…

Re: KX mini manual

Posted: Fri Apr 19, 2013 12:17 pm
by danboid
I most certainly do think non 4/4 time is a basic feature. 6/8 and 3/4 are common in traditional and popular western music. Its also disappointing that neither Ardour nor qtractor can handle gradual changes in tempo for MIDI tracks. Rosegarden and Muse don't suffer the same problem fortunately.

I've updated the JACK configuration page to include info on setting extra latency with a link to a guide on Latency from the LA wiki. The Audacity guide (this one http://manual.audacityteam.org/o/man/latency_test.html ?) may be clearer in some respects but it doesn't tell you how to convert latency from ms to frames as required by Cadence/JACK whereas jack_delay gives output in frames and ms.

Re: KX mini manual

Posted: Fri Apr 19, 2013 12:25 pm
by danboid
jack_delay doesn't seem to be on the KX iso presently - maybe it should be or is there another app included already that measures latency in frames?

EDIT

In fact, what'd be better Mr F would be if Cadence got a new button in the Extra Latency section that would run jack_delay and enter the correct latency values to be used against the current settings. Good idea?

Re: KX mini manual

Posted: Fri Apr 19, 2013 5:23 pm
by Thad E Ginathom
danboid wrote:Ye holy JACK configuration chapter has arrived!

http://www.wiki.linuxmusicians.com/doku ... figuration
Great. I've learned a couple of things from this and the previous chapter. Just simple things, but they can be the hardest to realise!

Re: KX mini manual

Posted: Fri Apr 19, 2013 5:46 pm
by Pablo
jack_delay doesn't seem to be on the KX iso presently - maybe it should be or is there another app included already that measures latency in frames?
Jack_delay is included in recent versions of jack (since one year or two). The command is "jack_iodelay"

Re: KX mini manual

Posted: Fri Apr 19, 2013 6:43 pm
by wolftune
right, jack_iodelay is the best option. What I want to see (and I don't know enough to write the docs myself) is a better KXStudio focused instructions for this. Setting this is a an important step and shouldn't be ignored. But I don't want to point people to those long explanations. I want a two paragraph at most thing that just tells people: do A B C and then your extra latency will be set and your overdubs will be lined up in all programs that recognize this
  • I'm happy to help create such documentation, but I'd need help. I don't understand how to do it clearly enough myself.

    Yes, the eventual ideal would be even better automation of this process, like where you just make the physical connections and push a button. I want docs that get as close as we can to that right now.

Re: KX mini manual

Posted: Sat Apr 20, 2013 12:45 am
by danboid
Thanks for pointing that out pablo! Indeed, KX already includes jack_iodelay so I shall test that tomorrow.

F: Thats OK. It was just an idea an I wasn't that set on it after thinking about it a bit more. I don't think it'd make things that much easier by integrating it into Cadence as its a very simple command anyway. I don't think jack_iodelay has any switches.

Wolftune- I agree that the doc I've linked to at the mo is at bit too much info on latency so we'll get that replaced with something much more concise shortly.

Re: KX mini manual

Posted: Sat Apr 20, 2013 7:16 am
by Thad E Ginathom
Does

$ man jack_iodelay

help you guys any (yes: it is there)? I only mention it because there is a tendency to forget the dear old man pages. In my early Unix days I did most of my learning from them.

Re: KX mini manual

Posted: Sat Apr 20, 2013 9:00 am
by danboid
I've got jack_iodelay working but unfortunately it doesn't auto-connect its input and output to your JACK IOs. I say unfortunately because we haven't covered making and breaking JACK connections with Catia or Claudia in the manual yet and the reader needs to know how to do that to use jack_iodelay so maybe we'll need a little, dedicated chapter on using jack_iodelay that will come after we've explained how to make JACK connections.

In my case, setting the extra latency only shaves off 27 frames (which equals using 13 for both Latency IO values) which is inperceivable and effectively makes no difference to the the roundtrip latency. If everyone's results are similar to mine, I wouldn't say it was worth mentioning jack_iodelay.

Is it worth having a new chapter on minimising latency or could this scare off newbs?

Re: KX mini manual

Posted: Sat Apr 20, 2013 10:00 am
by Thad E Ginathom
I don't think it would scare off newbs. I get fed up with hifi people talking about minimising latency, when it doesn't even matter to them, but Isn't it an important thing in studio work from the beginning?

Re: KX mini manual

Posted: Sat Apr 20, 2013 10:17 am
by danboid
Yes, it does matter here and its really not a compicated procedure - or so I thought until I tried using jack_iodelay with my 2i4 USB device and I just get nonsense.

Thankfully, male (the NON dev) has got a 2i4 now too so hopefully he can explain what I'm doing wrong. I need to know how this works for USB devices too before I write anything up.

EDIT

I've now updated the JACK config page and the TOC to refer to an upcoming chapter on using jack_iodelay