nama

Langue: en

Version: 2010-08-02 (ubuntu - 24/10/10)

Section: 1 (Commandes utilisateur)

NAME

Nama - Ecasound-based recorder, mixer and mastering system

SYNOPSIS

nama [options] [project_name]

DESCRIPTION

Nama is a text-based application for multitrack recording, mixing and mastering using the Ecasound audio engine developed by Kai Vehmanen.

Features include tracks, buses, effects, presets, sends, inserts, marks and regions. Nama runs under JACK and ALSA audio frameworks, automatically detects LADSPA plugins, and supports Ladish Level 1 session handling.

All editing under Nama is non-destructive. Effects are generally applied in realtime. A track caching (track freezing) function is also available.

The command prompt accepts Nama commands, Ecasound interactive-mode commands, shell commands and perl code, providing command history and autocompletion. The help system covers internal commands and LADSPA effects and includes keyword search.

By default, Nama displays a simple graphic interface while the command processor runs in a terminal window. The -t option provides a text-only interface for console users.

OPTIONS

--gui, -g
Start Nama in GUI mode
--text, -t
Start Nama in text mode
--config, -f
Specify configuration file (default: ~/.namarc)
--project-root, -d
Specify project root directory
--create-project, -c
Create project if it doesn't exist
--net-eci, -n
Use Ecasound's Net-ECI interface
--libecasoundc, -l
Use Ecasound's libecasoundc interface
--save-alsa, -a
Save/restore alsa state with project data
--help, -h
This help display

Debugging options:

--no-static-effects-data, -s
Don't load effects data
--no-state, -m
Don't load project state
--no-static-effects-cache, -e
Bypass effects data cache
--regenerate-effects-cache, -r
Regenerate the effects data cache
--no-reconfigure-engine, -R
Don't automatically configure engine
--debugging-output, -D
Emit debugging information
--fake-jack, -J
Simulate JACK environment
--fake-alsa, -A
Simulate ALSA environment
--no-ecasound, -E
Don't spawn Ecasound process
--execute-command, -X
Supply a command to execute

CONTROLLING NAMA/ECASOUND

The Ecasound audio engine is configured through use of chain setups that specify the signal processing network. After lauching the engine, realtime control capabilities are available, for example to adjust signal volume and to set playback position.

Nama serves as an intermediary, taking high-level commands from the user, generating appropriate chain setups for recording, playback, mixing, etc. and running the audio engine.

STATIC COMMANDS

Static commands affect future runs of the audio engine. For example, rec, mon and off determine whether the current track will get its audio stream from a live source or whether an existing WAV file will be played back. Nama responds to static commands by automatically reconfiguring the engine and displaying the updated track status.

DYNAMIC COMMANDS

Once a chain setup is loaded and the engine is launched, another set of commands controls the realtime behavior of the audio processing engine. Commonly used dynamic commands include transport "start" and "stop", playback repositioning commands such "forward", "rewind" and "setpos". Effects may be added, modified or removed while the engine is running.

CONFIGURATION

General configuration of sound devices and program options is performed by editing the .namarc file. On Nama's first run, a default version of .namarc is usually placed in the user's home directory.

Tk GRAPHICAL UI

Invoked by default if Tk is installed, this interface provides a subset of Nama's functionality on two windows, one for general control, the second for effects.

The main window has buttons for project create, load and save, for adding tracks and effects, and for setting the vol, pan and record status of each track.

The GUI project name bar and time display change 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 effects window provides sliders for each effect parameters. Parameter range, defaults, and log/linear scaling hints are automatically detected. Text-entry widgets are used to enter parameters values for plugins without hinted ranges.

The 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 command prompt, which will look something like this:
"nama [sax] ('h' for help)>"

In this instance, 'sax' is the current track.

When using sub-buses, the bus is indicated before the track:

"nama [Strings/violin] ('h' for help)>"

At the prompt, you can enter Nama and Ecasound commands, 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 (up to double semicolons ';;' if present) 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". "help_effect foo bar" lists all plugins/presets/controller containing both foo and bar. Tab-completion is provided for Nama commands, Ecasound-iam commands, plugin/preset/controller names, and project names.

Many effects have abbreviations, such as 'afx' for 'add_effect'.

TRACKS

Each track has a descriptive name (i.e. vocal) and an integer track-number assigned when the track is created. New user tracks initially belong to the Main bus.

Track output signals are usually mixed and pass through the Master track on the way to soundcard for monitoring.

The following sections describes track attributes and their effects.

WIDTH

Specifying 'mono' means the track has one input channel, which will be recorded as a mono WAV file. Mono track signals are automatically duplicated to stereo and a pan effect is provided.

Specifying 'stereo' for a track means that two channels of audio input will be recorded as an interleaved stereo WAV file.

Specifying N channels for a track ('set width N') means N successive input channels will be recorded as an N-channel interleaved WAV file.

REC/MON/OFF

Track REC/MON/OFF status guides audio processing.

Each track, including Master and Mixdown, has its own REC/MON/OFF setting and displays its own REC/MON/OFF status. Each bus also has REC, MON and OFF settings that influence the behavior of user tracks.

Track status

As the name suggests, REC status indicates that a track is ready to record a WAV file.

MON status indicates an audio stream is available from disk. This status requires the presence of a file matching the bus or track version number, if specified. A track set to REC with no live input will default to MON status.

OFF status means that no audio is available for the track from any source. A track with no recorded WAV files will show OFF status, even if set to MON.

Bus setting

We describe the effect of Main bus REC/MON/OFF settings on member tracks. (Sub-bus settings have similar effects on their tracks.)

The Main bus REC setting does not limit user track status in any way.

The Main bus MON setting disables recording for member tracks. Track REC status is forced to MON if a WAV file is available, or OFF if no WAV file is available.

The Main bus OFF setting forces all user tracks to OFF status, causing them to be excluded from the chain setup. Note: This setting is distinct from the action of the "mute" command, which sets the volume of the track to zero.

The Main bus MON mode triggers automatically after a successful recording run.

The mixplay command sets the Mixdown track to MON and the Main bus to OFF.

VERSION NUMBER

Multiple WAV files can be recorded for each track. These are distinguished by a version number that increments with each recording run, i.e. sax_1.wav, sax_2.wav, etc. All WAV files recorded in the same run have the same version numbers.

The version numbers of files for playback can be selected at the bus or track level. By setting the bus version to 5, you can play back version 5 of several tracks at once. Version 5 could signify the fifth take of a song, or the fifth song of a live recording session.

The track version setting, if present, overrides the bus setting. Setting the track version to zero restores control of the version number to the bus setting.

The Main bus version setting does not currently propagate to sub-buses. If you have sub-buses you must set bus version numbers for each separately if desired.

MARKS

Marks in Nama are similar to those in other audio editing software, with one small caveat: Mark positions are relative to the beginning of an Ecasound chain setup. If your project involves a single track, and you will be shortening the stream by setting a region to play, set any marks you need after defining the region.

REGIONS

The "region" command allows you to define endpoints for a portion of an audio file. Use the "shift" command to specify a delay for starting playback.

Only one region may be specified per track. To work around this limitation, use the "new_region" command to clone a track, specifying a new region definition. You can then independently control volume and pan of this new region, apply effects, etc.

The "link_track" command can clone tracks from other Nama projects.

EFFECTS

Each track gets volume and pan effects by default. New effects added using "add_effect" are applied after pan volume controls. You can position effects anywhere you choose using "insert_effect".

FADERS

Nama allows you to place fades on any track. Fades are logarithmic, defined by a mark position and a duration. An initial volume operator, -eadb, is additionally applied to tracks as necessary to enable this function.

SENDS AND INSERTS

The "send" command can route a track's post-fader output to a soundcard channel or JACK client in addition to the normal mixer input. Nama currently allows one aux send per track.

The "add_insert" command configures a pre- or post-fader send-and-return to soundcard channels or JACK clients. Wet and dry signal paths are provided, with a default setting of 100% wet.

Each track can have one pre-fader and one post-fader insert.

BUNCHES

A bunch is just a list of track names. Bunch names are used with the keyword "for" to apply one or more commands to to several tracks at once. A bunch can be created with the "new_bunch" command. Any bus name can also be treated as a bunch. Finally, a number of special bunch keywords are available.
rec, mon, off
All tracks with the corresponding setting in the current bus
REC, MON, OFF
All tracks with the corresponding status in the current bus

BUSES

SUB BUSES

Sub buses enable multiple tracks to be routed through a single mix track before feeding the main mixer bus (or possibly another sub bus.)

The following commands create a sub bus and assign three tracks to it. The mix track takes the name of the bus and is stereo by default.

         # create a bus named Strings feeding a mix track named Strings
         add_sub_bus Strings 
 
         # create tracks for the sub-bus
         add_tracks violin cello bass
 
         # move the tracks from the Main bus (default) to the Strings bus
         for violin cello bass; set bus Strings
 
         # use the mix track to control bus output volume
         Strings vol - 10
 
 

SEND BUSES

Send buses can be used as instrument monitors, or to send pre- or post-fader signals from multiple user tracks to an external program such as jconverter

ROUTING

General notes

While Nama can address tracks by either a name and a number, the chain setups use the track number exclusively.

The Master track (mixer output control) is always chain 1, the Mixdown track is always chain 2.

Nama uses Ecasound loop devices where necessary to connect two tracks, or to allow one track to have multiple inputs or outputs. Each loop device adds one buffer, which increases latency.

Flow diagrams

Let's examine the signal flow from track 3, the first available user track. Assume track 3 is named ``sax''.

We will divide the signal flow into track and mixer sections. Parentheses show the track number/name.

The stereo outputs of each user track terminate at Master_in, a loop device at the mixer input.

Track, REC status

     Sound device   --+---(3)----> Master_in
       /JACK client   |
                      +---(R3)---> sax_1.wav
 
 

REC status indicates that the source of the signal is the soundcard or JACK client. The input signal will be written directly to a file except in the special preview and doodle modes, or if "rec_disable" is issued.

Track, MON status

     sax_1.wav ------(3)----> Master_in
 
 

Mixer, with mixdown enabled

In the second part of the flow graph, the mixed signal is delivered to an output device through the Master chain, which can host effects. Usually the Master track provides final control before audio output or mixdown.

     Master_in --(1)--> Master_out --+--------> Sound device
                                     |
                                     +-->(2)--> Mixdown_1.wav
 
 

Mastering Mode

In mastering mode (invoked by "master_on" and released "master_off") the following network, receives the Master track signal as input and provides an output to the soundcard or WAV file.

                           +-(Low)-+ 
                           |       |
     Eq-in -(Eq)-> Eq_out -+-(Mid)-+- Boost_in -(Boost)-> soundcard/wav_out
                           |       |
                           +-(High)+
 
 

The Eq track hosts an equalizer.

The Low, Mid and High tracks each apply a bandpass filter, a compressor and a spatialiser.

The Boost track applies gain and a limiter.

These effects and their default parameters are defined in the configuration file .namarc.

Mixdown

The "mixdown" command configures Nama for mixdown. The Mixdown track is set to REC (equivalent to "Mixdown rec") and the audio monitoring output is turned off (equivalent to "main_off").

Mixdown proceeds after you start the transport.

Preview and Doodle Modes

These non-recording modes, invoked by "preview" and "doodle" commands tweak the routing rules for special purposes. Preview mode disables recording of WAV files to disk. Doodle mode disables MON inputs while enabling only one REC track per signal source. The "arm" command releases both preview and doodle modes.

TEXT COMMANDS

[% qx(./emit_command_headers pod) %]

DIAGNOSTICS

On any change in setup, the GUI display updates and "show_tracks" command is executed automatically showing what to expect the next time the engine is started.

You can use the "chains" command to verify the Ecasound chain setup. (The Ecasound command "cs-save-as mysetup.ecs" will additionally store all engine data, effects as well as routing.)

The "dump" command displays data for the current track. The "dumpall" command shows all state that would be saved.

This is the same output that is written to the State.yml file when you issue the "save" command.

BUGS AND LIMITATIONS

No waveform or signal level displays are provided.

No latency compensation across signal paths is provided at present, although this feature is planned.

SECURITY CONCERNS

If you are using Nama with the NetECI interface (i.e. if Audio::Ecasound is not installed) you should block TCP port 2868 if your computer is exposed to the Internet.

INSTALLATION

The following command, available on Unixlike systems with Perl installed, will pull in Nama and other Perl libraries required for text mode operation:

PERL_MM_USE_DEFAULT=1 cpan Audio::Nama

To use the GUI, you will need to install Tk:

"cpan Tk"

You may want to install Audio::Ecasound if you prefer not to run Ecasound in server mode:

"cpan Audio::Ecasound"

You can pull the source code as follows:

"git clone git://github.com/bolangi/nama.git"

Consult the BUILD file for build instructions.

SUPPORT

The Ecasound mailing list is a suitable forum for questions regarding Nama installation, usage, feature requests, etc., as well as questions relating to Ecasound itself.

https://lists.sourceforge.net/lists/listinfo/ecasound-list

PATCHES

The main module, Nama.pm, and its sister modules are concatenations of several source files. Patches against these source files are preferred.

AUTHOR

Joel Roth, <joelz@pobox.com> Copyright (c) 2009-2010 by Joel Roth.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.