Zathras-1 the all new time stretching technology we developed for BpmDj has finally been integrated into the product. What is so cool about this ? We can finally timestretch like a pro. More info about the timestretcher at http://werner.yellowcouch.org/log/zathras/
I cannot properly express my hatred towards C++. I really cannot put it into words. You would think that starting a sentence with insults and strong words would do it, but no, it would only appear as a feeble attempt to express how I really feel. A polite ‘fuck you C++’… will only be reciprocated with a ‘fuck you too Werner’. So I’m totally at a loss. Even comparing C++ its complexities and ambiguous sense of morality to Merkel would not do it justice. Sometimes, I feel like I would like to pick up the phone, call Stroustroup, pull him through the cable and have ‘a nice and friendly chat’ with him. Will not do either because he already speaks like the Swedish cook. Maybe the best comparison would be a Kafkaesque interaction between administration trying to rob your of your will to live and you as the victim. I feel as if I want to die.
The timestretcher I’ve been working on is going ahead quite well. I’m currently working on timestretcher parameter changes. When changing the tempo, the segments should still align correctly. In the image each color is a new synthesized segment. As can be seen, they overlap nicely. A wave from one segment is picked up by the next, and so on.
I’m currently optimizing my timestretcher. Just to give an idea of the speed we need to achieve: with a windowsize of 4096 samples and an overlap of 16 frames. We have about 5.8 milliseconds between frame calculations. Now, this is stereo which means that we only have 2.9 milliseconds/frame. In each frame we have to detect sine waves, extract them relocate them to other positions. Typically we have around ~600 peaks per frame. That leaves us about 4.8 microseconds per peak. Each peak must be detected, extracted, repositioned, resampled and added to the final frame again. Currently I manage to do this in 13 microseconds. And now the push is on. Can we speed this further up with a factor 2.7 ?
This year we will again be at the Chaos Communication Camp 2015 (which takes place around Berlin)
At CCC 2011, we gave a talk on how BpmDj performs its audio analysis. Two years later, at OHM 2013, we explained how the nearest neighbor detection and associated weight matrix is created. This year, we won’t talk about the project anymore, but instead give you the opportunity to meet the developers.
Actually, we want you to come to us with ~100 tracks and an idea for a mix. We will then sit together and create that mix. As a reward you will receive one of our heat sensitive ‘stay-tuned-stay-sharp-keep-mixing’ cups.
The old VCC/2 line, which I originally made with a second opamp has been replaced with a 100K resistor pair. Not the best solution because now it hums even louder. The grounds and the opamp bias have been properly decoupled this time (still hum). Some of the capacitor values have been lower in cutoff frequency (still hum). I tried placing a resistor over the input to remove the hum. That works if the resistor is ~680 Ohm. Yet in that case, if there is an input signal, it is barely amplified (no hum, no signal). Putting the entire thing in a metal box did not do a thing. So no pickup of magenetic fields (still hum). Replacing the powersupply with a batterypack resulted in >huray< no hum ! So it is most certainly a power supply problem. Hum removal is a non trivial problem. Grmpf.
Some new components arrived for the audio splitter. Yes that knob will go to 11. Now ordering PCB print material and acid. Which is actually not really acid, but hey what did those hippies know anyway ?
Another fine example of Googles ‘write once, let others fix our problems’. Even at this moment (June 2014) the ‘patch’ is still not in the released sdk. To solve the problem replace
if (!mContext.getPackageManager().queryIntentServices(serviceIntent, 0).isEmpty()) {with
PackageManager pm=mContext.getPackageManager();
List<ResolveInfo> intentServices = pm.queryIntentServices(serviceIntent, 0);
if (intentServices != null && !intentServices.isEmpty())Then in the dispose code
replace
if (mContext != null) mContext.unbindService(mServiceConn);with
if (mContext != null && mService!=null) mContext.unbindService(mServiceConn);I hope this helps.
In June/July 2011 I had the misfortune to program for a Symbian/Nokia phone. Really bad experience. Below a list of all the shit I had to go through to get QtCreator working somewhat.
I was so happy that I could stop programming for/on this utter swamp of a platform.