NAME
Audio::Ecasound::Multitrack - Perl extensions for multitrack audio processing
Nama - Lightweight multitrack recorder/mixer
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.
By default, Nama starts up the Tk GUI interface. The command line interface runs simultaneously in the terminal.
STATIC AND DYNAMIC COMMANDS
It may be helpful to observe that our commands for audio processing fall into two categories:
STATIC COMMANDS
Some commands control the chain setup that will be used to configure Ecasound for audio processing. I refer to them as static commands. Static commands have no effect while the engine is running, come into play only the next time the transport is armed.
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 corresponding audio stream will be recorded to a file or played back from an existing file.
DYNAMIC COMMANDS
Once the transport is running, another subset of commands controls the audio processing engine, for example adjusting effect parameters or repositioning 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.
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. Text-entry widgets are used to enter parameters for effects where hinting is not available.
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). Live recording and mixdown can take place simultaneously.
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 if necessary 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. Usually the lines are split on semicolons and the parts are executed sequentially, however if the line begins with eval or ! the entire line will be given to the corresponding interpreter.
You can access command history using up-arrow/down-arrow.
Type help for general help, help command for help with command, help foo for help with commands containing the string foo.
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. As with other engine operations, a start command must be issued for mixdown to commence.
All user tracks belong to the Tracker group, which has a group REC/MON/OFF setting and a default version setting that advances automatically so that the default will be to play back the most recent set of multitrack recordings all together.
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 recording has created new WAV files.
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.
BUGS AND LIMITATIONS
loop_enable must be issued as a text command.
GUI volume sliders are linear scaled.
Fails with a Segfault under kernel compiled for amd64.
EXPORT
None by default.
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 (C) 2007 Joel Roth