hydrogen - Modern Drum Machine

hydrogen [options]

This manual page briefly documents the hydrogen command.

hydrogen is a drum machine that has numerous features and a modern graphical user interface based on QT 3. Hydrogen incorporates a sample-based stereo audio engine, which can load sound samples in .wav, .au, .aiff and .flac formats.

Hydrogen features a pattern-based sequencer, unlimited number of patterns and ability to chain patterns into a song. There can be up to 64 ticks per pattern with induvidual level per event and variable pattern length there.

You can create up to 32 instrument tracks and control their volume, mute, solo and pan.

You can make use of layering ability in Hydrogen. If you have ever dealed with real acoustic drums, then you know that if you kick a drum harder or softer it won't sound just louder or quieter. It will also sound a bit different. This is where layers step onto the stage. A layer represents a definable range of a level you kick a drum -- so called velocity. You assign appropriate samples to each layer (up to 16) of an instrument and in pattern editor you define velocity for each kick. The instrument will sound then exactly like the real one. Which is the point.

Your song can be bounced to a WAV track in a non-realtime mode. This is quite convenient if you are low on CPU and/or RAM and you don't want to run any JACKified multitrack recorder in order just to capture Hydrogen's output.

If your drum line sounds too fine and too precise, you can use unique human velocity, human time and swing functions. You can make people think you have hired a dumb drummer for your band, if you let those sliders go to the very top.

Hydrogen has drivers for both OSS (also, emulated by ALSA) and audio server JACK plus assignable JACK ports. There also is ALSA MIDI input with assignable midi-in channel (1..16, ALL) for you to record events for pattern editor from a MIDI keyboard. Hydrogen can be synced with other JACK capable applications via JACK Transport mechanism.

One of the ways to arrange your song is to try a different instrument set which is called a drumkit. A drumkit is a archive file which contains all the samples for a pattern editor and some metadata like the order their appear in a pattern editor. You can easily create your own drumkits and share them with anyone. Currently the most recommendable file format for samples is FLAC, which provides lossless compression up to fair 35%.

This program follow the usual GNU command line syntax, with long options starting with two dashes (`--'). A summary of options is included below. For a complete description, see the Info files.

-d, --driver AUDIODRIVER

Use the selected audio driver (jack, oss). Choosing 'jack' will give you realtime processing and low latency, if JACK server is running with the same privilegies. Choosing 'oss' will give you usual sad perfomance.

-s, --song FILE

Load a song (*.h2song) at startup. Hydrogen will open a song file you define.

-n, --nosplash

Start without splash screen.

-V, --verbose

Print a lot of details about what Hydrogen is actually doing. This is good for fancy testing, while for a gdb test you will need to compile Hydrogen with --enable-debugging-messages option. If ever you want to.

-v, --version

Show version of program and quit. Use this option, if you are running a Linux distro that is not based on either RPM or DEB, so that there is no packages database to find out, what version of Hydrogen is currently installed in your system.

-h, --help

Show this help message

You can read thorough documentation from within Hydrogen. Go to 'Help' menu and choose 'User manual' menu item.

Here is just a short example of using command line for Hydrogen

$ hydrogen -d jack -N -v -s /home/alexandre/hydrogen_songs/oh_my.h2song

In this case Hydrogen will start as JACK client, without a splash screen, with debbugging info and it will load a song called oh_my.h2song from /home/alexandre/hydrogen_songs/ directory.

Following manpages are of use:

hydrogenPlayer(1), jackd(1), jackstart(1)

You will find latest development news, docs and additional drumkits at

http://hydrogen.sourceforge.net

Feel free to subscribe to a mailing list at

http://sourceforge.net/projects/hydrogen

and take part in discussion of Hydrogen's development. The more you communicate, the sooner new features will be expected. Don't hesitate to give voice!

This manual page was written by

Alessandro Cominu <comix@users.sourceforge.net>

and updated by

Alexandre Prokoudine <avp@lrn.ru>