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Advanced Linux Sound Architecture
Advanced Linux Sound Architecture (ALSA) is a software framework and part of the Linux kernel that provides an application programming interface (API) for sound card device drivers. Some of the goals of the ALSA project at its inception were automatic configuration of sound-card hardware and graceful handling of multiple sound devices in a system. ALSA is released under GNU General Public License, GPL-2.0-or-later and GNU Lesser General Public License, LGPL-2.1-or-later. On Linux, sound servers, like sndio, PulseAudio, JACK Audio Connection Kit, JACK (low-latency professional-grade audio editing and mixing) and PipeWire, and higher-level APIs (e.g OpenAL, Simple DirectMedia Layer#Subsystems, SDL audio, etc.) work on top of ALSA and its sound card device drivers. ALSA succeeded the older Linux port of the Open Sound System (OSS). History The project to develop ALSA was led by Jaroslav Kysela, and was based on the Linux device driver for the Gravis Ultrasound sound card. It sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Softvol
Softvol is an Advanced Linux Sound Architecture (ALSA) Plug-in (computing), plugin that adds a software based Loudness, volume control to the ALSA audio mixer (alsamixer). This is helpful when a sound card does not have a computer hardware, hardware volume control. The softvol plugin is built into ALSA and does not require a separate installation. Another use case of the softvol is when a hardware volume control is unable to amplify the sound beyond certain threshold and thus renders an audio file too quiet. In this case software amplifiers can be created in order to boost the volume level at the price of sacrificing some quality. Many modern software pieces that are able to play audio files have their own, ALSA(or any other sound system)-independent softvol controls. References External linksAlsa Opensrc Org - Independent ALSA and linux audio support site A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JACK Audio Connection Kit
JACK Audio Connection Kit (or JACK; a recursive acronym) is a professional sound server Application programming interface, API and pair of daemon (computing), daemon implementations to provide real-time, low-latency connections for both audio and MIDI data between applications. JACK was developed by a community of open-source developers led by Paul Davis (programmer), Paul Davis (who won an Open Source Award in 2004 for this work) and has been a key piece of infrastructure and the de facto standard for professional audio software on Linux since its inception in 2002. The server is free software, licensed under GNU General Public License, GPL-2.0-or-later, while the library is licensed under GNU Lesser General Public License, LGPL-2.1-or-later. Implementations The JACK API is standardized by consensus, and two compatible implementations exist: jack1, which is implemented in plain C and has been in maintenance mode for a while, and jack2 (originally jackdmp), a re-implementation i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plug-in (computing)
In computing, a plug-in (or plugin, add-in, addin, add-on, or addon) is a software component that adds a specific feature to an existing computer program. When a program supports plug-ins, it enables customization. A theme or skin is a preset package containing additional or changed graphical appearance details, achieved by the use of a graphical user interface (GUI) that can be applied to specific software and websites to suit the purpose, topic, or tastes of different users to customize the look and feel of a piece of computer software or an operating system front-end GUI (and window managers). Purpose and examples Applications may support plug-ins to: * enable third-party developers to extend an application * support easily adding new features * reduce the size of an application by not loading unused features * separate source code from an application because of incompatible software licenses. Types of applications and why they use plug-ins: * Digital audio workstation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High- And Low-level
High-level and low-level, as technical terms, are used to classify, describe and point to specific goals of a systematic operation; and are applied in a wide range of contexts, such as, for instance, in domains as widely varied as computer science and business administration. High-level describe those operations that are more abstract in nature; wherein the overall goals and systemic features are typically more concerned with the wider, macro system as a whole. Low-level describes more specific individual components of a systematic operation, focusing on the details of rudimentary micro functions rather than macro, complex processes. Low-level classification is typically more concerned with individual components within the system and how they operate. Features which emerge only at a high level of description are known as epiphenomena. Differences Due to the nature of complex systems, the high-level description will often be completely different from the low-level one; and, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Library (computer Science)
In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subroutines, classes, values or type specifications. In IBM's OS/360 and its successors they are referred to as partitioned data sets. A library is also a collection of implementations of behavior, written in terms of a language, that has a well-defined interface by which the behavior is invoked. For instance, people who want to write a higher-level program can use a library to make system calls instead of implementing those system calls over and over again. In addition, the behavior is provided for reuse by multiple independent programs. A program invokes the library-provided behavior via a mechanism of the language. For example, in a simple imperative language such as C, the behavior in a library is invoked by using C's normal function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User-space
A modern computer operating system usually segregates virtual memory into user space and kernel space. Primarily, this separation serves to provide memory protection and hardware protection from malicious or errant software behaviour. Kernel space is strictly reserved for running a privileged operating system kernel, kernel extensions, and most device drivers. In contrast, user space is the memory area where application software and some drivers execute. Overview The term user space (or userland) refers to all code that runs outside the operating system's kernel. User space usually refers to the various programs and libraries that the operating system uses to interact with the kernel: software that performs input/output, manipulates file system objects, application software, etc. Each user space process normally runs in its own virtual memory space, and, unless explicitly allowed, cannot access the memory of other processes. This is the basis for memory protection in tod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread-safe
Thread safety is a computer programming concept applicable to multi-threaded code. Thread-safe code only manipulates shared data structures in a manner that ensures that all threads behave properly and fulfill their design specifications without unintended interaction. There are various strategies for making thread-safe data structures. A program may execute code in several threads simultaneously in a shared address space where each of those threads has access to virtually all of the memory of every other thread. Thread safety is a property that allows code to run in multithreaded environments by re-establishing some of the correspondences between the actual flow of control and the text of the program, by means of synchronization. Levels of thread safety Software libraries can provide certain thread-safety guarantees. For example, concurrent reads might be guaranteed to be thread-safe, but concurrent writes might not be. Whether a program using such a library is thread-safe depends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Full-duplex
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex communication systems: full-duplex (FDX) and half-duplex (HDX). In a full-duplex system, both parties can communicate with each other simultaneously. An example of a full-duplex device is plain old telephone service; the parties at both ends of a call can speak and be heard by the other party simultaneously. The earphone reproduces the speech of the remote party as the microphone transmits the speech of the local party. There is a two-way communication channel between them, or more strictly speaking, there are two communication channel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardware Mixing
Hardware acceleration is the use of computer hardware designed to perform specific functions more efficiently when compared to software running on a general-purpose central processing unit (CPU). Any transformation of data that can be calculated in software running on a generic CPU can also be calculated in custom-made hardware, or in some mix of both. To perform computing tasks more quickly (or better in some other way), generally one can invest time and money in improving the software, improving the hardware, or both. There are various approaches with advantages and disadvantages in terms of decreased latency, increased throughput and reduced energy consumption. Typical advantages of focusing on software may include more rapid development, lower non-recurring engineering costs, heightened portability, and ease of updating features or patching bugs, at the cost of overhead to compute general operations. Advantages of focusing on hardware may include speedup, reduced power ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Musical Instrument Digital Interface
MIDI (; Musical Instrument Digital Interface) is a technical standard that describes a communications protocol, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, computers, and related audio devices for playing, editing, and recording music. The specification originates in the paper ''Universal Synthesizer Interface'' published by Dave Smith and Chet Wood of Sequential Circuits at the 1981 Audio Engineering Society conference in New York City. A single MIDI cable can carry up to sixteen channels of MIDI data, each of which can be routed to a separate device. Each interaction with a key, button, knob or slider is converted into a MIDI event, which specifies musical instructions, such as a note's pitch, timing and loudness. One common MIDI application is to play a MIDI keyboard or other controller and use it to trigger a digital sound module (which contains synthesized musical sounds) to generate sounds, which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Sound System
The Open Sound System (OSS) is an interface for making and capturing sound in Unix and Unix-like operating systems. It is based on standard Unix devices system calls (i.e. POSIX read, write, ioctl, etc.). The term also sometimes refers to the software in a Unix kernel that provides the OSS interface; it can be thought of as a device driver (or a collection of device drivers) for sound controller hardware. The goal of OSS is to allow the writing of sound-based applications that are agnostic of the underlying sound hardware. OSS was created by Hannu Savolainen and is distributed under four license options, three of which are free software licences, thus making OSS free software. API The API is designed to use the traditional Unix framework of open(), read(), write(), and ioctl(), via special devices. For instance, the default device for sound input and output is /dev/dsp. Examples using the shell: cat /dev/random > /dev/dsp # plays white noise through the speaker cat / ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
