Unemployed

August 28, 2013 jeremyarm, audio, bakkerij, instrument, linux, unemployed, workshop2 Comments

As of 2013-09-30 I will be unemployed. Can’t tell any details here but I’m already very busy looking for new job opportunities, applying for jobs and doing job interviews. If all goes well I can start right away at a new employer. I even had to take my CV offline because I risked getting too many offers.

I’ve also accepted an offer to do some Linux audio consultancy work. Just received my contract and I’m stoked about it. And no, can’t share any details on that either. When it comes to details this is a lousy blogpost, leaving you a bit in the dark, sorry about that. But as soon as I can tell more I’ll do so. For the moment I think it’s ok to say that I’ll be doing consultancy work for a project to create an instrument based on an ARM device. It’s a bit of a dream come true, doing paid Linux audio R&D. So back to work, I also have to set up a website for my consultancy activities. And get everything ready for the first workshop at De Bakkerij.

Carla on the Raspberry Pi

July 26, 2013November 8, 2015 jeremyarm, aubio, audio, carla, chroot, dssi, falktx, gig, host, kxstudio, ladspa, linux, linuxsampler, linuxvst, lv2, pi, piem, plug_in, plugin, rasbian, raspberry, raspberrypi, repository, rpi, sf2, sfz, vst, zynaddsubfx19 Comments

Last week I managed to get Carla running on my RPi. Carla is a really nice plugin host that supports the most important plugin frameworks available for Linux (LV2, DSSI, LADSPA and VST) with some awesome extra features like a built-in ZynAddSubFX synth and support for SF2, SFZ and GIG files. The latter didn’t work until yesterday but I managed to compile LinuxSampler (which is needed by Carla in order to be able to load SFZ and GIG files) for the RPi with the help of Paul Brossier aka piem from the Aubio project.

I just wrote him a mail:

Hello Paul,

I’m trying to package LinuxSampler for Raspberry Pi but I’m running into an issue when compiling which fails with a message related to RTMath.h. After some googling I ended up here:
http://bb.linuxsampler.org/viewtopic.php?f=2&t=514#p3156
So I started scouring the interwebs and found this:
http://packages.qa.debian.org/l/linuxsampler/news/20050806T210205Z.html
Where there is a reference to a possible fix. But the diff.gz that contains the patch is untraceable. I know this announcement is almost 8 years old but do you think you still have the diff or maybe an idea what changes you made to the code?

Thanks in advance and keep up the good work with Aubio!

Best regards,

Jeremy Jongepier

And guess what, he replied almost instantly! He gave me some pointers where to add some extra code and even though I’m not a coder I started trying things out. But then I stumbled upon actual patches to resolve this issue. I needed both the ARM and atomic patch and after applying those LinuxSampler compiled flawlessly in my Raspbian ARM chroot. The few lines of code I cooked up myself were almost identical so I got quite far actually. I should really pick up learning how to code, I think I’d learn fast.

So after compiling LinuxSampler I could rebuild Carla against the freshly created LinuxSampler libs. Installed the deb on my RPi and loaded some SFZ’s. It all worked like a charm. Carla is like a Swiss Army Knife, I’m really starting to appreciate this piece of software. Kudos to falkTX! And thanks to Paul Brossier for responding so quickly and helping me to get on the right track.

Carla running on the Raspberry Pi

Open AV Productions: Fabla

July 11, 2013 jeremyaudio, drumkv1, fabla, haaren, harry, linux, lv2, openavproductions, plugin, sampler, samplv1, sorcer2 Comments

Who recalls the times when Linux audio users were craving for a sampler LV2 plugin? Soon we will have even more choice besides drumkv1 and samplv1, enter Fabla! No idea what Fabla stands for but it sure looks fablalous.

Fabla by Open AV Productions uses the same release model as used with Sorcer recently. Instead of a year it took 9 days to push back the release date of Sorcer and hopefully the same thing will happen with Fabla. I’d love to get my hands on this plugin so I’ve done my part to speed up the release date.

Edit: Fabla has been released within 8 days!

More ARM goodies II

July 9, 2013 jeremyarm, audio, bbb, beaglebone, black, debian, kernel, latency, linux, low, lowlatency, mk808, pi, raspberry, raspberrypi, real, realtime, rk3066, rockchip, rpi, time, ug80x, wheezy2 Comments

Received the BeagleBone Black (BBB) and the MK808 with a RK3066 SoC. My first impressions are really positive. Especially the BBB is quite an awesome device that I’m probably going to use a lot in favor of the Raspberry Pi. At first glance I had something like, the BBB blows the RPi away, but as soon as I started looking for documentation on how to put Debian on it for instance it became clear that the RPi is still the device to beat. The RPi community is huge, documentation for it is well laid out and working with the RPi is just so easy. The BBB on the other hand lacks a vivid community, is $10 more expensive and a lot more difficult to work with. Take the Debian install for example, seems quite some work to get that going.

The MK808 is surely an improvement over the UG80X I already own. It comes with a HDMI port instead of a HDMI plug, has an extra USB OTG port, a heatsink, hardware serial console access, a reset button and a power indicator LED. The pre-installed Android version looks better too. I flashed my RT kernel recovery image on it, inserted the Micro SD from my UG80X and it booted without any issues. So I’m going to pursue my goal to get a real-time, low-latency environment running on a RK3066 based device on the MK808 and find another purpose for the UG80X.

Edit: Getting Debian to work on the BBB is actually quite easy: http://elinux.org/BeagleBoardDebian#Demo_Image
Next time I’ll promise to make better use of my Google skills.

Hacking an Android TV stick, the sequel

July 4, 2013 jeremyamsynth, android, audio, jack, jackd, kernel, linux, patch, patchset, pi, raspberry, raspberrypi, real, real_time, realtime, rk3066, rockchip, rpi, rt, stick, time, tv, xrun, xruns3 Comments

jeremy@rk3066:~$ uname -a
Linux rk3066 3.0.36-rt58 #1 SMP PREEMPT RT Thu Jul 4 13:18:23 CEST
2013 armv7l GNU/Linux

Managed to compile and run a real-time kernel on the Android TV stick with the RK3066 SoC. Packaged the latest version of amSynth (1.4.0 which has been released recently), installed it, fired up JACK and amSynth and so far no xruns, nothing. And this is with -p64!

jackd -P84 -p32 -t2000 -dalsa -dhw:Device -n3 -p64 -r44100 -s -P

I should measure the latency of the $2 USB audio interface I’m using to find out what the total latency of this set-up is. Well, at least I got the system latency for usage with softsynths like amSynth down to 64/44100*2=3ms. Now that’s a usable situation.

jeremy@rk3066:~$ lsusb | grep -i c-media
Bus 002 Device 006: ID 0d8c:000e C-Media Electronics, Inc. Audio Adapter (Planet 
UP-100, Genius G-Talk)
jeremy@rk3066:~$ cat /proc/asound/cards
 0 [RK29RK1000     ]: RK29_RK1000 - RK29_RK1000
                      RK29_RK1000
 1 [HDMI           ]: ROCKCHIP_HDMI - ROCKCHIP HDMI
                      ROCKCHIP HDMI
 2 [Device         ]: USB-Audio - Generic USB Audio Device
                      Generic USB Audio Device at usb-usb20_host-1.1, full speed

A big pro of this stick is that it suffers less from SD card corruption than my RPi. Yesterday evening I wrecked up yet another SD card when testing my RPi with a real-time kernel, it’s getting a bit cumbersome. Speaking of real-time kernels, it was quite some work to apply the RT patchset to the RockChip kernel source. Had to add stuff by hand and when I finally got everything in place it wouldn’t compile. But I managed to solve all the build errors. After flashing the kernel image the TV stick wouldn’t boot of course, it hung at some point. But I quickly saw that the issue was with the SD card reader and that it was similar to the SD card reader issue on the RPi for which I found a workaround. So I added an #ifdef clause to the RockChip SD card reader driver, recompiled, reflashed and wham, it continued booting. Now I have to clean up my build directory and get a usable diff of it against the pristine RK3066 kernel sources.

More ARM goodies

July 3, 2013 jeremyandroid, arm, audio, beagleboard, beaglebone, black, board, cape, cubieboard, dev, development, embedded, geekbuying, guitarix, jack, jackd, linux, mk808, pcduino, pi, raspberry, raspberrypi, rk3066, rockchip, rpi, stick, tv, tweakers.netLeave a comment

Bought another Android TV stick based on the RK3066 SoC, the MK808 which is as far as I’ve understood kind of the default board to hack on.

MK808 Android TV stick

Also bought a BeagleBone Black development board. Why? Because apparently JACK runs well on it, also with USB interfaces (no need for the ALSA softmode option!) so I assume the USB implementation is better than those of the Raspberry Pi and the RK3066 based board I currently own. And I could get it cheaper over here in The Netherlands than other viable alternatives like the pcDuino or Cubieboard, also because of a coupon code I found on tweakers.net so I got a price reduction of a few Euros. Another reason why I bought it are the so-called capes that are available for this board. These capes are basically add-on boards and the cape that has my most attention is the audio cape. I’m thinking about buying that specific cape, solder two Neutriks on the audio in and out and turn it into the easiest DIY guitar effect box ever. Of course with guitarix loaded on it, the devs have done an incredible amount of work recently to get guitarix running flawlessly and painlessly on ARM dev boards like the BeagleBone Black.

BeagleBone Black

BeagleBone Audio Cape

Workshops Music Production with Open Source Software

June 24, 2013 jeremyamp, audio, bakkerij, cabinet, castricum, daw, debian, drum, floss, foss, guitar, instrument, linux, machine, mastering, mixing, modeling, music, open, pi, plugin, plugins, production, raspberry, raspberrypi, recording, rk3066, rk3188, rockchip, rpi, sampler, sequencer, software, source2 Comments

Starting September 7th I’m going to conduct a series of 6 workshops on music production with open source software at De Bakkerij in Castricum. With software I also mean the operating system so the OS I’m going to use will be an open source based one (probably Ubuntu or Debian). So basically it’s a series of workshops on music production with Linux Audio.

Last week I had something like, what the heck, I’m just going to mail De Bakkerij to ask if they’re interested since they host more DIY initiatives like the workshops inititiative I proposed. I didn’t expect much of it but I immediately got an enthusiastic e-mail back from the promotor of De Bakkerij. So after a few mails back and forth it was a done deal.

Rough outline of the workshops:

Introduction and base principles of open source software and using it for music production. What is open source, why use it, how does the open source audio ecosystem look like and will my hardware work?
Recording with open source software. What software is available (DAW), how to use it during the recording process, base principles of recording instruments and vocals (I’ll be focusing on home recording and not recording complete bands).
Making music with open source software. Softsynths, samplers, drum machines, amp/cabinet modeling, sequencers, trackers, DAWs, MIDI/OSC, plugin frameworks etc.
Mixing and mastering with open source software. What software is available, what kind of hardware do I need, base principles of mixing and mastering.
Showcasing the possibilities of the usage of open source software with the focus on low-cost solutions like the Raspberry Pi and RockChip based devices.
Concluding workshop: listen to and discuss the musical projects made by the attendees, discussion on music production with open source software.

There’s no fee for attending the workshops but you do need a notebook or netbook and an empty USB memory stick of at least 4GB.

Bricking the UG802 Android TV stick

June 20, 2013 jeremyandroid, audio, custom, finless, irq, jack, jack1, jackd, kernel, linux, pi, raspberry, raspberrypi, rk3066, rom, rpi, stick, tv, ug802, usbLeave a comment

Pulled out my soldering iron, soldered a reset button and a switch to boot into recovery on the PCB and connected my UG802 clone/revision to my TV. Nothing. lsusb. Crap, it boots in flash mode. Let’s try reflashing the whole bloody thing. Well that works so the NAND is not defective or anything. Reboot. Nothing, lsusb still reports the device is in flash mode. So I removed all my soldering efforts which I really regretted because it was quite nicely done given my poor soldering skills and tried again. Still nothing. Arrrggghhhh. Enjoyed a cold Warsteiner and let it rest.

Today I brought the device with me to the office. Hooked it up to a Windows machine, ran the ROM flash tool from Finless’ custom ROM package for this device and powered it up. I was greeted with the most ugly Android boot animation I had ever seen. But at least the device works again so thanks Finless!

So now I can move on again. I had Jack1 running on it so it should be possible to turn this device into a very cheap, yet powerful alternative to do real-time, low-latency audio. Compared to the Raspberry Pi JACK already consumed way less CPU (12% on the RPi compared to 2% on the RK3066 device with the same JACK settings) and I noticed the device has some more IRQ’s so if I could get all of those threaded that should give me some more flexibility to get everything working in a more stable way. I did have to disable WiFi otherwise the whole USB stack crashed after starting JACK. Also tried with an external WiFi dongle, same issue. I can even generate xruns when pressing keys on an attached keyboard. So it’d be really nice if I had serial console access to this thing. But I’ll figure that out too. And maybe the USB part of the kernel can be tweaked to improve things on the USB level.

Hacking the UG802 Android TV stick

June 16, 2013 jeremyandroid, galland, howto, linux, manual, mk808, rk3066, rk3188, rockchip, stick, tutorial, tv, ug8024 Comments

Lucky me. Brought the Android TV stick with me to work after I got it in the mail. Showed it to my boss and he immediately ordered one too, not a UG802 though but a RK3188 based device. The RK3188 is a quad core ARM CPU while the UG802 comes with a RK3066 dual core CPU. The goal is to hack this RK3188 based device to see if it can be used for one of the projects we’re working on. Only very recently (about two weeks ago) the kernel source has been released and people managed to run Linux on it just a few days ago. Can’t wait to hack it. During working hours. Awesome.

Unlucky me. Apparently the TV stick I purchased is some kind of UG802 revision or clone. Very confusing. But I can boot Linux on it as it’s a RK3066 based device so I’m ok. I think I’ll order another TV stick but then one with better community support, like the MK808.

Unlike the RK3188 based devices the RK3066 based devices have been available a while longer so there is quite some useful information available on how to get Linux running on it. First thing is to get a Linux kernel on it that allows you to boot into a Linux rootfs that resides on a MicroSD card. For the Linux rootfs I’ve chosen to use Debian Wheezy. For the kernel I used Galland’s concise yet effective howto. All the details on how I set up the TV stick in order to boot it with Linux can be found on the Installing Linux on a RK3066 based device page.

Ardour with video and LV2 MIDI plugins chaining support

June 15, 2013 jeremyardour, audio, gareus, hka, horus, linux, lv2, midi, qtractor, robin2 Comments

Got so absorbed hacking my UG802 that I completely missed this: https://community.ardour.org/node/7219

So not only can you add video to your Ardour project but now it’s also possible to chain multiple LV2 plugins that accept MIDI. The video support is the great work of Robin Gareus and it was actually a presentation on this functionality that got me acquainted with the Linux Audio meetings at the HKU almost 3 years ago. So yes, he’s been working on it quite a while so I assume it works well.

I have actually never worked with Ardour, I’ve always used Qtractor. But maybe it’s getting time to check out Ardour too, especially now that the MIDI part is stabilizing.

autostatic.com

Linux Audio Ramblings

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