Mine the Harvest

Recently I decided to revive my interest in playing the guitar. I took a few lessons back around 1988, but didn’t stick with it. Over the years  my desire to pick it up again has cropped up here and there, but either I was too busy with life and college, or my guitar was in another state, or whatnot. However, I was recently reunited with my guitar, but not my old amp. I decided to see how I might use my Linux box to allow my to play through it, and perhaps have some effects processing as well. I quickly discovered the rich extent of audio tools available for Linux, and even for the guitar specifically. I hit a gold mine.

I quickly found several USB sound cards with 1/4″ jack inputs, which were well supported under Linux, were readily available – and at a modest price. I ordered a Behringer UCG 102 off Amazon for all of $29.

Behringer UCG 102

I also discovered Rakarrack, an full featured guitar effects processing suite for Linux.  I had no issues getting Rakarrack installed, and anxiously awaited the arrival of the new sound card. If you play the guitar, you really have to check out Rakarrack – it is amazing.

Rakarrack - Sound Like a God

When the Behringer arrived I was shocked to discover the EnergyXT2 recording software it came with nativity supported Linux. Displayed right on the CD sleeve was a an nice capital “L” and advertised Linux support:

Yep - it runs on Linux.

This, of course, I would have to try – simply as a matter of principle. I soon discovered however several issues with this software, and my solutions to them are below.

NOTE: I should say however that the Behringer Guitar to USB interface worked flawlessly, and in short order I had connected my guitar, fired up the Jack audio server, launched Rakarrack and was playing. The effects provided by Rakarrack include: distortion, chorus, reverb, flanger, digital delay and many others. Wow – this is like having an array of effects pedals for free, and they sound great.  And it should be mentioned as well that the open source Ardour recording software worked without requiring anything beyond finding and installing the RPM. So . . . why even bother with getting EnergyXT2 to work? Well, because it’s there. I loved the idea of getting Linux software with a product I bought, and by God I intended to see it work.

Do you need to do this too? Well, that’s up to you. You can certainly use Ardour to record with, and it works extremely well. But if you want to try out EnergyXT, and use it with Jack, and with MIDI, and especially if you are running 64-bit – then read on.

If all you want is a basic working EnergyXT2 without Jack support, that should not be too difficult:

0) First – you need to download the latest version of EnergyXT2 for the website. The version which was shipped has a bug which caused it to fail returning:

X Error of failed request: BadImplementation (server does not implement operation)
Major opcode of failed request: 139 (MIT-SHM)
Minor opcode of failed request: 5 (X_ShmCreatePixmap)
Serial number of failed request: 382
Current serial number in output stream: 384
X Error of failed request: BadDrawable (invalid Pixmap or Window parameter)
Major opcode of failed request: 55 (X_CreateGC)
Resource id in failed request: 0x2a000a4
Serial number of failed request: 383
Current serial number in output stream: 384

This is easily solved by downloading the updated version. You might want to grab the manual too.

At this point it should start and work correctly, but you will not have Jack support. For that you need to continue with the next steps. This assumes some familiarity with compiling things, obtaining required libraries, and some basic debugging – it is not really difficult, but if you have not compiled things much it may be a learning experience.

1) The version of libaam.so provided with the software has several limitations, the most significant of which is that it does not support the Jack audio server.  Now – there are two routes to take here:

A) Download the source for libaam.so from the EnergyXT libaam site and compile using the instruction there, or:

B) Download and compile the source for from the libaam Jack Sourceforge project. This is most certainly the better route to take as it supports more MIDI channels and also can build a QT Interface to configure it to work with Jack. Simply download, untar and continue with the steps below.  Note this contains its own readme and make file, and QT interface, unlike the basic version for the EnergyXT site.

2) Next, I was building this on a 64-bit OpenSuse 11.3 system. The fact of building this on a 64-bit platform introduces a number of additional factors which have to be addressed. If you were to build this on a 32-bit platform, it would be easier.  If using a 64-bit environment (perhaps like Studio64) the first thing you need to do is ensure you have the 32-bit versions of the libraries you will need, AS WELL AS 32-bit versions of gcc, glibc, etc. These are going to be called different things depending on your distro, but you are looking for things like:

libasound2-devel
libjack-devel-1.9.5-2.8.i586 (get 32-bit version from webpin)
alsa-plugins-jack qjackctl
libqt4-devel-4.6.3-2.1.1.i586
alsa-devel-1.0.23-2.12.x86_64
glibc-32bit-2.11.2-3.3.1.x86_64
gcc45-32bit-4.5.0_20100604-1.12.x86_64
gcc-c++-32bit-4.5-4.2.x86_64

And maybe . . .

libSDL_mixer-1_2-0-32bit
libSDL_mixer-1_2-0

Should you receive any build errors complaining about libs you know you have, may need to make some symlinks for several of the libraries, such as:

sudo ln -s /usr/lib/libasound.so.2.0.0 /usr/lib/libasound.so
sudo ln -s /usr/lib/libjack.so.0.1.0 /usr/lib/libjack.so
sudo ln -s /lib/libgcc_s.so.1 /lib/libgcc_s.so

Getting all the 32-bit libraries you need may take a few tries – each time you compile you may be presented with some new library needed – but you should be able to work through them and fortunately there are a limited number required.

If you do not have 32-bit gcc, you may get messages similar to:

paracelsus@Callandor:~/energyXT/libaam-0.0.2> g++ -m32 -shared -lasound -ljack jack.cpp -o libaam.so
/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/bin/ld:
i386:x86-64 architecture of input file `/usr/lib64/gcc/x86_64-suse-linux/4.3/crtbeginS.o’ is incompatible with i386 output

This is simply due to missing the proper gcc and g++ 32-bit packages – oops. (While I had the necessary 32-bit libs for qt and Jack, I  inadvertently had not installed 32-bit gcc and g++ libs, so it indeed was missing the 32-bit version of crtbeginS.o, just like it says.

2) This then allowed libaam.so to build, and you should be able to use the library at this point. You most likely want the configuration interface too, but building xt2-config failed with a missing qmake-qt4, though it was installed. That was corrected with a symlink:

ln -s /usr/lib/qt4/bin/qmake /usr/bin/qmake-qt4

3) The next problem building xt2-config was with it expecting a 32-bit build environment – Note that -m32 is specified in the Makefile for libaam, but NOT in the config/Makefile for xt2-config, thus:

g++ -c -m32 -pipe -g -Wall -W -D_REENTRANT -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/QtCore -I/usr/include/QtGui -I/usr/include -I. -I. -o moc_configw.o moc_configw.cpp
g++  -o xt2-config main.o configw.o moc_configw.o    -L/usr/lib -lQtGui -L/usr/lib -L/usr/X11R6/lib -lQtCore -lpthread
/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib/libQtGui.so when searching for -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib/libQtGui.so when searching for -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib/libQtGui.so when searching for -lQtGui
/usr/lib64/gcc/x86_64-suse-linux/4.3/../../../../x86_64-suse-linux/bin/ld: cannot find -lQtGui

Now, I can see that g++ is not being called with -m32 when it links the three compiled files main.o configw.o moc_configw.o To get this to build correctly I modified the Makefile in config/Makefile (which is called from the Makefile in the build root), and added:

#CFLAGS        = -pipe -g -Wall -W -D_REENTRANT $(DEFINES)
CFLAGS        =  -m32 -march=i386 -pipe -g -Wall -W -D_REENTRANT $(DEFINES)
#CXXFLAGS      = -pipe -g -Wall -W -D_REENTRANT $(DEFINES)
CXXFLAGS      =  -m32 -march=i386 -pipe -g -Wall -W -D_REENTRANT $(DEFINES)

And . . .

####### Build rules

all: Makefile $(TARGET)

$(TARGET): ui_config.h $(OBJECTS)
        $(LINK) $(LFLAGS) $(CXXFLAGS) -o $(TARGET) $(OBJECTS) $(OBJCOMP) $(LIBS)

The result is a working libaam.so you can copy to your energyXT folder (backup and replace the existing) which supports Jack, and a working xt2-config (move it from config/ to /usr/bin)

xt2-config for Jack Audio

Of course on a 32-bit OS EnergXT2 should just run out of the box (as long as you have downloaded an updated copy) but you still would not have Jack support (which is really the way to go), or the QT config interface, and as more users move to 64-bit and RT kernels for audio applications, this may come in handy.