Help with analyzing stems

This issue occurs when you import stems that are at a higher sample rate than 48 kHz as a track source within Stem Creator.
**ANSWER/SOLUTION**
Reduce the sample-rate to 48000

 

Hey everyone
I've been emailing NI to fix a bug and it's been 3 years... they still say they haven't had time to get around to it...

When I create Stems using ALAC, it spits out a proper lossless file (lets say about 300 or 400mb for a 7 minute track) which sounds right for 4 tracks of uncompressed audio.
When I go to play it traktor, it says that it can't analyse it.

I use ALAC because if I use WAV files then it Stem creator outputs an mp3 quality file (about 70mb). Which just doesn't do it in sound quality, lots of the high frequencies get lost. Easy to listen to the difference when playing both files at the same time in a DAW and flipping the phase on one of them, it's crazy how much gets lost in the Stem file using their encoder.

Alac seems to be the only way to get lossless audio out of stems... but they never got it to work.

Anyone been able to find a workaround for this?? Not sure if this is a Mac issue only...

 

So, I'm fiddling around a bit with creating stems those days, and here is what I found worked for me. I'm only using wav files outputted by Spleeter as source.

First of all, Stem creator does the job on OSX, just drop all the wav files in their proper place, drop maybe the vocals wav file in the Master lane, adjust the compressor thing to taste and then export.

This will create a very reasonable stem file, in term of quality and size. I've taken a look with Spek, and each channel looks like it's encoded in AAC 256 VBR.

Now to import that file in Traktor is very problematic, as it refuse to analyse it. The only way to achieve it is to first drop the stem into a deck. It will appear in the Stems pane in the collection. Then right click on it, select 'check consistency', then click 'Analyse', you'll get the mass analysis import pane, leave 'all' selected, click ok and it will finally work.

Now to produce lossless stems, you can't do it with Stem Creator. That is, it will work at creating a stem with all the parts lossless if you feed it alac files, and you can see in Spek it worked but there's no way it will analyse in Traktor. I generate the alac using XLD, someone said that it might work if you bounce it in Logic but who has time for that?

So far the only proper way to generate lossless is to use the command line tool. More on that maybe later. The only drawback is that you can't apply the compressor/limiter.

 

Great! If you have any update on using the command line tool, please let us know. This would be gold! Loosing the compression and limiting wouldn't be a problem for me at least, don't use them anyway... instead I route the audio to a software that uses VSTs and there use a proper good compressor and limiter.

NI support told me that they were going to do it, but after a while I received an email saying that they won't have time for it in the near future...

The AAC files are ok, but if you duplicate/flip phase on the track to listen to the differences between lossless and AAC it's quite substantial unfortunately. At least IMO not good enough quality to play in good PA systems.

 

Ok, I've started typing up something, but I'm realizing that it's a bit tedious to detail all the steps. How experienced are you with the Terminal, so far I'm assuming you don't know a thing.

Also, I'm half thinking of wiping up a script to simplify things up a little, but that may take me a bit I've never done that.

So, any experience?

 

A script would definitely save the day and your assumption is right, I only use terminal when read somewhere what to type in. It's great to know that there is a light at the end of the tunnel !

 

Ok, download this: https://github.com/axeldelafosse/stemgen/archive/master.zip



In the archive there's a folder named ni-stem, put it on your desktop. Open Terminal (in Applications>Utilities). Type "cd " without the quotes and drag the ni-stem folder into terminal. It will look like this: cd /Users/nico/Desktop/stemgen-master/ni-stem. Press return. The prompt will change to (base) YourcomputerName:ni-stem. You are now in the ni-stem folder.

Type "chmod +x ni-stem" without the quotes, it will make the ni-stem app executable. Type "./ni-stem", it should display:


usage: NI-Stem [-h] {create,info} ...

NI-Stem: error: too few arguments


Now you can use it to make a stem. Type "./ni-stem create -s " and then drag your wav files of the separate stem elements into the terminal, in the same manner than before, separate by a space. Then type " -x" and drag your wav file of the complete song or just drag one pf the separate stem element you've already used. This is what is supposed to be the full mixed track, and what will create what's displayed in the full overview in Traktor. Then type -f alac


Should look like this: ./ni-stem create -s /Users/nico/Desktop/drums.wav /Users/nico/Desktop/bass.wav /Users/nico/Desktop/others.wav /Users/nico/Desktop/vox.wav -x /Users/nico/Desktop/others.wav -f alac


Hopefully, this will create in the ni-stem folder on your desktop a lossless stem file.

 

For me it worked until the 3rd step.
1 - Changing directory
2 - chmod +x ni-stem (to create application)
3 - ./ni-ste (when I type this I get this message: -bash: ./ni-stem: is a directory)

Here's what was on my terminal:

Last login: Wed Aug 19 03:01:04 on ttys000
Nunos-MBP:~ nunocabral$ cd /Users/nunocabral/Desktop/stemgen-master
Nunos-MBP:stemgen-master nunocabral$ chmod +x ni-stem
Nunos-MBP:stemgen-master nunocabral$ ./ni-stem
-bash: ./ni-stem: is a directory
Nunos-MBP:stemgen-master nunocabral$

anything I'm missing?
Thanks again

 

You're not into the proper directory, copy the ni-stem folder that's inside stemgen-master on your desktop and use that. The stemgen-master folder can then be discarded.

 

Perfect, thank you! passed that step
After, when I drag the files to make the stem I get this message:
"list indices must be integers, not str"


Last login: Wed Aug 19 16:43:40 on ttys000
Nunos-MBP:~ nunocabral$ cd /Users/nunocabral/Desktop/stemgen-master/ni-stem
Nunos-MBP:ni-stem nunocabral$ chmod +x ni-stem
Nunos-MBP:ni-stem nunocabral$ ./ni-stem
usage: NI-Stem [-h] {create,info} ...
NI-Stem: error: too few arguments
Nunos-MBP:ni-stem nunocabral$ ./ni-stem create -s /Users/nunocabral/Desktop/test/Kick\ n\ Bass.wav /Users/nunocabral/Desktop/test/Percs.wav /Users/nunocabral/Desktop/test/Leads.wav /Users/nunocabral/Desktop/test/Tech.wav -x /Users/nunocabral/Desktop/test/Full\ track.wav -f alac
list indices must be integers, not str
Nunos-MBP:ni-stem nunocabral$


I think I typed it right, with spaces and removed any special characters from the file name just in case (like Full Track G#...)
Thank you!

 

Hi Nico, could you please let me know if you saw my last post?


"
Perfect, thank you! passed that step
After, when I drag the files to make the stem I get this message:
"list indices must be integers, not str"


Last login: Wed Aug 19 16:43:40 on ttys000
Nunos-MBP:~ nunocabral$ cd /Users/nunocabral/Desktop/stemgen-master/ni-stem
Nunos-MBP:ni-stem nunocabral$ chmod +x ni-stem
Nunos-MBP:ni-stem nunocabral$ ./ni-stem
usage: NI-Stem [-h] {create,info} ...
NI-Stem: error: too few arguments
Nunos-MBP:ni-stem nunocabral$ ./ni-stem create -s /Users/nunocabral/Desktop/test/Kick\ n\ Bass.wav /Users/nunocabral/Desktop/test/Percs.wav /Users/nunocabral/Desktop/test/Leads.wav /Users/nunocabral/Desktop/test/Tech.wav -x /Users/nunocabral/Desktop/test/Full\ track.wav -f alac
list indices must be integers, not str
Nunos-MBP:ni-stem nunocabral$


I think I typed it right, with spaces and removed any special characters from the file name just in case (like Full Track G#...)
Thank you!"

 

NI... so many updates and you can spend 1 second to fix the FLAC bug...

 

Has a bug report been filed? I see you've been emailing support, but I'm just wondering if the message is hitting the proper channel.
But then again, are they even updating the stem creator now?
I think one of the splitting apps exports NI stem formats. Next time I'm taking a look at these things, I'll let you guys know if I find any way to create lossless stem files NI will accept through such means.
In the mean time, I'll probably also try your Terminal route. Thank you for taking the time to put that online.
S.

 

They have finally fixed it! I waiting years and years... bought d2s, sold d2s lol etc
But just a couple of weeks ago I saw it fixed!
So now if stem files are created with ALAC audio files we get proper lossless stems !
Would be cool to have that option right on the stem creator to choose the output conversion but I’m already happy with this. changing my live set now from Ableton to traktor with some Allen Heath k2. To bad they stopped making the D2s, the little screens would have been awesome
Cheers !

 

Yeah I bought a pair of D2s on the cheap, been meaning to get around to finding use for them, the hurdle of having to hack these things together yourself is not small. They are quite nice, but I don’t use them much. They make my S4 mk3 that much more free-standing, with that big screen. The beat sequencer is very basic, and would take some practice, but all in all its a fun piece of kit, especially if you get it on the cheap.

 

Native instruments will next release a smaller version of the d2’s, the d3’s... with faders for stems and remix decks, knobs for all the fx etc! wouldn’t that be nice...