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mirrors: nosignal.fi (eu) / seul.org (us) / sourceforge.net (us)

• What is Ecasound and why should you use it?
• Primary tasks Ecasound is designed for
• Tasks for which you should choose a different tool
• Features
• Ecasound technology: Key Features
• Supported audio inputs/outputs
• Sound processing components
• Parameter controllers
• Notes about implementation
• User-interfaces

For a quick introduction, browse through the Ecasound README file.

• Harddisk/Multitrack Recording and Mixing - [examples]
  Ecasound’s flexible chain-based design makes it a powerful tool for multitrack recording and mixing. Once you read through the examples, you’ll notice that recording&mixing has never been this easy. ;)


• Effect Processing - [examples]
  Ecasound offers a wide range of effect algorithms (including support for LADSPA effect plugins). Using Ecasound’s chain-concept, effects can be combined in various ways. It’s also possible to save a complex effect setup as a preset. Later on these presets can be used just like a native effect. An important part of the effect system is dynamic control. Oscillators, envelopes and MIDI-control sources can be used to control effect parameters. Check out these few examples of Ecasound preset system and LADSPA plugins and be impressed! :)


• Realtime Signal Routing - [examples]
  Route audio signals through external devices or use your computer as an fx-processor for external signals.


• Audio File Playback and Format Conversion - [examples]
  As Ecasound supports a wide range of file formats and audio devices, it can also be used as a player and a converter. Notice! There are some issues you should be aware of. See below for more info.


• Automating Audio Processing Tasks - [examples]
  Ecasound suits well to scripting and automation. It can be called from shell scripts, launched from graphical programs or used from remote terminal sessions. Additionally Ecasound Control Interface (ECI) offers a more flexible but yet simple way to interact with the Ecasound engine. Implementations of ECI are available for multiple languages (for example C, C++, Python, Perl, PHP and elisp.

• MIDI Sequencing
  Work around: Use an external sequencer application and run it in sync with Ecasound either using the JACK transport API or MIDI (MMC/MTC). This requires that the sequencer provides sufficient support for the synchronization mechanisms.


• Sequencing Small Audio Clips
  Ecasound’s design does not suit well to arranging a large number of small audio clips into continuous tracks.
  Work around: Use applications such as SoundTracker and synchronize them to Ecasound.


• Sound Synthesis
  Ecasound only provides a very limited set of primitives for audio generation.


• Bitwise File Conversions
  Before processing, Ecasound converts all input data to its internal format (defaults to 32bit-float/44100Hz). This is not optimal if you want to perform bitwise conversions from one audio file format to another.
  Work around: Better tools for this kind of work are Sox and libsndfile tool sndfile-convert.

• Novel user-interface concept
  What makes Ecasound unique is its non-graphical user-interface. The basic working principle of ecasound is similar to the widely used gdb (software debugging) and mysql (database admin) tools. Ecasound allows the user to perform most common tasks directly from the terminal console. Repeating or otherwise complicated tasks can be easily turned into shell scripts or ECI apps. Ecasound tries to follow the time-tested UNIX design practises - see for example The Art of UNIX Programming by Eric S. Raymond.


• Highly optimized real-time engine
  Ecasound’s engine has been developed with real-time reliability as the top priority. The engine clearly separates real-time safe subsystems from non-RT subsystems such as storage access, user-interface code and memory management. This allows Ecasound to deliver reliable playback and recording in all circumstances - even under significant system load.


• Ability to adapt to runtime environment
  Ecasound will automatically adjust buffering parameters and other performance related options based on analysis of runtime environment and the requested task. Ecasound does not require you to run it with special privileges, but if available (for example the permission to utilize real-time scheduling), Ecasound will take full advantage and choose more aggressive parameters allowing to further minimize processing latencies while at the same time not risking reliability.


• Support for new Linux audio technology
  Ecasound has mature support for JACK audio server (including full transport support), LADSPA and LV2 effect plugins, OSC Open Source Control control protocol and ALSA the Linux kernel sound subsystem. Ecasound developers are longtime members of the Linux audio development community.
  
  
• Portability and minimal external dependencies
  Ecasound runs on various operating systems (GNU/Linux, FreeBSD, Mac OS X, Solaris, Cygwin/win32) and architectures (IA32, PowerPC, ARM, SPARC). Ecasound implements most of its core functionality without relying on external packages. Although Ecasound can utilize numerous external packages, they are all optional. As a mimimum, Ecasound needs POSIX (with 1003.1c thread support) and ANSI C++ runtimes.

• Supported Audio Inputs/Outputs
  • Soundcards via ALSA (Advanced Linux Sound Architecture), audio subsystem for Linux-2.6 and newer kernels
  • JACK, a low-latency audio server
  • Soundcards via OSS (/dev/dsp), Open Sound System, audio subsystem for various Linux/BSD/UNIX systems
  • aRts, audio server (KDE 2.x and newer)
  • RIFF WAVE (.wav) files, 8/16/24/32bit non-compressed PCM
  • Ecasound Wave Files (.ewf), simple wrapper format for recording and mixing purposes
  • Raw/headerless sample data (.raw)
  • CDDA (.cdr), on-disc format used on audio-CDs
  • MPEG 1.0/2.0 (layers 1, 2 and 3) (.mp3), using mpg123 for input and lame for output
  • Ogg Vorbis (.ogg), using ogg123 and oggenc from the vorbis-tools package
  • Module formats supported by MikMod, XM, IT, S3M, MOD, MTM, 669, STM, ULT, FAR, MED, AMF, DSM, IMF, GDM, STX
  • AIFF (.aiff) and Sun/NeXT audio (.au/.snd) formats using libaudiofile
  • W64 (.w64), PVF, VOC and many other formats using libsndfile [2.3.2 and newer]
  • FLAC audio files using FLAC [Ecasound 2.3.4 and newer]
  • AAC audio (.aac/.m4a/.mp4) support using FAAC/FAAD2 [Ecasound 2.3.4 and newer]
  • MIDI files (.mid) - using Timidity++
  • standard input/output streams (stdin, stdout) and named pipes

• Sound processing components
  • amplify, panning, DC-fix, volume normalization
  • channel mixing and routing
  • dynamics: noise gate, various compressors, limiter
  • filters: lowpass, highpass, bandpass, bandreject, resonant lowpass, resonant bandpass, resonator, comb, inverse comb, allpass
  • envelope modulation: pulse gate, tremolo
  • time modulation: chorus, flanger, phaser, pitch shift, fake-stereo
  • delays: multitap delays, reverbs
  • LADSPA and LV2 effect plugins - hundreds of sound processing plugins available

• Controllers (for modifying effect parameters during processing)
  • sine oscillator
  • generic oscillator (either using an envelope table with static points or with linear interpolation)
  • linear envelopes (fade-in, fade-out, custom/generic envelopes)
  • MIDI continuous controllers (CC)
  • OSC (Open Source Control) apps

• floating-point sample representation is used for all processing (defaults to 32bit)
• written in ANSI C++ (interface libraries available for C, Python, Perl, Ruby, PHP, etc)

• Ecasound is designed to be a usable and intuitive tool for creative work
• Console-mode ecasound - [man page]
  • the primary user-interface
  • can easily be used in batch-files, macros, etc
  • passive textmode - all parameters are given on the command line
  • interactive textmode - like passive, but program can be controlled with simple commands (read from stdin using GNU readline)
• Ecatools command-line utils - [man page]
  • ecaconvert (convert from one file format to another, supports batch processing)
  • ecafixdc (fix DC-offset, supports batch processing)
  • ecalength (prints audio file information)
  • ecanormalize (normalize volume level, supports batch processing)
  • ecaplay (play files using the default output, supports batch processing)
  • ecasignalview (monitor signal volume in realtime)
• Various 3rd party user-interfaces and separate applications
  • See announcements on ecasound-list mailing list

Copyright © 2000-2020 Kai Vehmanen
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