NAME
Audio::Ecasound::Multitrack - Perl extensions for multitrack audio processing
nama - Multitrack recording/mixing application
SYNOPSIS
nama options project_name
OPTIONS
- -d project_root
-
Use project_root as Nama's top-level directory. Default: $HOME/nama
- -g
-
Graphical mode, with text interface in terminal window
- -t
-
Text-only mode
- -f config_file
-
Use config_file instead of default .namarc
- -c
-
Create the named project
- -a
-
Save and reload ALSA mixer state using alsactl
- -m
-
Suppress loading of saved state
- -e
-
Don't load static effects data
- -s
-
Don't load static effects data cache
DESCRIPTION
Audio::Ecasound::Multitrack provides class libraries for tracks and buses, and a track oriented user interface for managing runs of the Ecasound audio-processing engine.
Nama is a recorder/mixer application that configures Ecasound as a single mixer bus.
In its default mode Nama provides a Tk GUI interface, with a command line interface running simultaneously in the terminal window.
STATIC AND DYNAMIC COMMANDS
It may be helpful to observe commands or actions for audio processing fall into two categories:
Some commands control the Ecasound chain setup that will be used for audio processing.
For example, setting the REC/MON/OFF status of a track or bus determines whether it will be included next time the transport is armed, and whether the audio stream will be recorded to a file or played back from an existing file.
This is the first part: you set up tracks to your liking. Then you issue the arm command to configure and connect the Ecasound engine.
Other commands influence the audio processing engine as it runs, for example volume and pan controls, and any changes to the position of the playback head.
FIRST RUN
On the first run the program prompts the user for permission to create the configuration file, usually $HOME/.namarc, and a recording projects directory, $HOME/nama by default. You should then edit .namarc to suit your audio configuration.
PERSISTENCE
Project state can be stored/retrieved. These data are stored by default in the State.yml file in the project directory.
LADSPA
Nama will automatically detect locally available LADSPA plugins provided you have the listplugins and analyseplugin programs which are part of LADSPA SDK.
Tk GRAPHICAL UI
Invoked by default, the Tk interface provides all functionality on two panels, one for general control, the second for effects.
Logarithmic sliders are provided automatically for effects with hinting. Otherwise text-entry widgets are used.
After issuing the arm or connect commands, the GUI time display changes color to indicate whether the upcoming operation will include live recording (red), mixdown only (yellow) or playback only (green).
The text command prompt appears in the terminal window during GUI operation. Text commands may be issued at any time.
TEXT UI
Press the Enter key to get the following command prompt.
Enter command:
You can now enter commands. Nama and Ecasound commands may be entered directly. You may also enter Perl code preceded by "eval" or shell code preceded by "!".
Multiple commands on a single line are allowed if delimited by semicolons.
Note that if an "eval" or "!" appears at the beginning of a command, the entire line will be give to the corresponding interpreter.
In other situations, the lines are split on semicolons and the parts are executed sequentially.
You can access history using up-arrow/down-arrow (Ctrl-P/Ctrl-N on Mac).
Type help for general help, help command for help with command.
TRACKS
Each track has a descriptive name (i.e. vocal) and an integer track-number assigned when the track is created.
Multiple WAV files can be recorded for each track. These are identified by version number. Identical version numbers indicate WAV files recorded at the same time. Version number increments automatically so that the order of version numbers follows the time sequence of the recordings.
Each track, including Master and Mixdown, has its own REC/MON/OFF setting and displays its own REC/MON/OFF status. The Master bus has only MON/OFF status. Setting REC status for the Mixdown bus has the same effect as issuing the mixdown command.
All user tracks belong to the Tracker group, which has a group REC/MON/OFF setting and a default version setting.
Setting the group to MON (text command group_monitor) forces user tracks with a REC setting to MON status if a WAV file is available to play, or OFF status if no audio stream is available.
The group MON mode triggers automatically after a recording that leaves files longer than a second.
The group OFF setting (text command group_off) excludes all user tracks from the chain setup, and is typically used when playing back mixdown tracks. The mixplay command sets the Mixdown group to MON and the Tracker group to OFF.
A track with no recorded WAV files that is set to MON will show OFF status.
SAMPLE SESSION
Here is a typical sequence of text commands to:
- record instrumental parts - separately record a vocalist - mix down all to a stereo tract
create marys_little_helper # new project add guitar; r1 # record track 'guitar' from input 1 add piano; r2 # record track 'piano' from input 2 add drums; r3 # record track 'drums' from input 3 arm # generate chain setup and connect engine start
(perform)
stop show # new versions of guitar, piano and drums appear group_monitor # set group MON arm; start # review recording
group_record # rec-enable group guitar mon; piano mon; drums mon # set three tracks to monitor mode add vocals; r2 # record track 'vocals' from input 2 arm start
(perform vocals)
stop
group_monitor # set group MON arm; start # review recording
(adjust effects)
mixdown; show # set mixdown mode, show to confirm arm; start # record mixdown track
(engine runs)
mixplay # mixdown playback mode arm; start # review completed mix
DIRECTORY STRUCTURE
$project_root is the directory where your project files, including WAV files you record, will go. $project_root is defined in the first non-comment line of your .namarc file.
File or directory Explanation -------------------------------------------------------------------------- $HOME/.namarc Nama configuration file $project_root/project_name/.wav WAV files we record will be stored here $project_root/project_name/Setup.ecs Ecasound chainsetup, dynamically generated $project_root/project_name/State.yml Default save file for project parameters $project_root/project_name/.namarc Project-specific configuration
BUGS AND LIMITATIONS
- A project should be loaded or created before issuing other commands. Many commands will crash the system if issued without a project loaded.
- The loop_enable command is available only in the default mode. Timer events are currently handled through the Tk graphic toolkit, which requires X.
- GUI volume sliders are linear scaled.
- The post-recording cleanup routine deletes newly recorded soundfiles under 44100 bytes in size.
- To be able to run entirely without Tk and without X you will need to delete the line containing 'use Tk' from Multitrack.pm.
EXPORT
None by default.
DEPENDENCIES
This module requires the following Perl modules.
Data::YAML
IO::All
Getopt::Std
Tk
Audio::Ecasound
Parse::RecDescent
Data::YAML
File::Find::Rule
File::Spec::LinkThe Ecasound audio processing libraries must also be installed. Ecasound may be obtained from http://ecasound.seul.org/ecasound/ or as precompiled binary packages for your Un*x distribution.
LADSPA plugins are also recommended. In that case, the LADSPA utility programs listplugins and analyseplugin must also be installed in a directory in your execution PATH. See http://ladspa.org .
file, a BSD utility program, is also needed. It is most likely already provided with your operating system.
AVAILABILITY
CPAN, for the distribution.
Pull source code using this command:
git clone git://github.com/bolangi/nama.git
AUTHOR
Joel Roth, <joelz@pobox.com>
COPYRIGHT AND LICENSE
Copyright 2007 by Joel Roth
This library is licensed under GPL version 2. See the file COPYING (included in the distribution) for terms and conditions.
ABSTRACT
Classes and user interfaces for multitrack recording with the Ecasound audio processing engine