NationMaster - Encyclopedia: Audio Compression Manager

This article is in regard to the different deprecated audio components in older versions of Microsoft Windows. Windows Vista contains an overhauled entirely different audio architecture. Image File history File links Emblem-important. ... Windows redirects here. ... Windows Vista is a line of graphical operating systems used on personal computers, including home and business desktops, notebook computers, Tablet PCs, and media centers. ... Windows Vista (formerly codenamed Windows Longhorn) has many significant new features compared with previous Microsoft Windows versions, covering most aspects of the operating system. ...

Audio Compression Manager

Audio Compression Manager is the Windows Multimedia framework that manages audio codecs (compressor/decompressors). ACM can also be considered an API specification. A codec must conform to the implicit ACM specification to work with Windows Multimedia. ACM files can be recognized by their filename extension .acm . A multimedia framework is a software structure (usually a set of software libraries) that handles media on a computer and through a network. ...

ACM is considered an outdated framework/API and Microsoft now encourages the use DirectShow. However, unlike ACM and the related Video Compression Manager (VCM), DirectShow provides no means to encode files for end-users but requires developers to build end to end graphs for encoding content. ACM also does not support VBR audio streams, therefore newer codecs like MPEG-4 AAC, Ogg Vorbis, FLAC etc cannot be supported through ACM. Logo of the DirectX Media SDK - the first time DirectShow was distributed under its current name. ... Video for Windows was a multimedia technology developed by Microsoft that allowed Microsoft Windows to play digital video. ... Logo of the DirectX Media SDK - the first time DirectShow was distributed under its current name. ... Variable bitrate (VBR), or less commonly variable bit rate, is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. ... MPEG-4 is a standard used primarily to compress audio and visual (AV) digital data. ... MPEG-4 AAC DRM encoding as used in the iTunes Store Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. ... This page is about the audio compression codec. ... FLAC, an acronym for Free Lossless Audio Codec, is a popular file format for audio data compression. ...

KMixer

KMixer is the Kernel Audio Mixer driver, a part of WDM Audio in various version of Microsoft Windows which handles the mixing of multiple sound buffers into an output. In computing, the Windows Driver Model (WDM) â€” also known (somewhat misleadingly) at one point as the Win32 Driver Model â€” is a framework for device drivers that was introduced with Windows 98 and Windows 2000 to replace VxD, which was used on older versions of Windows such as Windows 95 and... Windows redirects here. ...

Controversies

The KMixer was designed to aid the applications by relieving them from the need to perform the mixing of audio streams, especially on low-end sound cards that didn't support multiple sound streams. However, it introduced some significant problems.

First, the latency of KMixer is around 30 ms and it cannot be reduced, because this component sits just right above the port class audio driver, so every audio stream, including those issued by DirectSound (except in cases of hardware mixing) and WinMM, come through the kernel mixer. Latency is a time delay between the moment something is initiated, and the moment one of its effects begins. ... DirectSound is software supplied by Microsoft that resides on a computer with the Windows operating system. ...

Then, KMixer tried to mix every data format that passed through it, even those which it did not support. It caused various problems with movie players that tried to pass AC3-encoded surround sound streams through S/PDIF output of the sound card to an external home cinema receiver. Description Dolby Digital is the trademark for Dolby Laboratories AC-3 audio coding system. ... Multichannel audio is the name for a variety of techniques for expanding and enriching the sound of audio playback by recording additional sound channels that can be reproduced on additional speakers. ... TOSLINK connector (JIS F05) 75 ohm coaxial cable with BNC-to-RCA adapter. ... A 3 metres/119 inch projection screen with a high-definition television image. ... The word receiver has a number of different meanings: In communications and information processing, a receiver is the recipient (observer) of a message (information), which is sent from a source (object). ...

A new kernel-mode API, Direct Kernel Streaming, had to be introduced in order to bypass the KMixer and avoid problems associated with it. Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ...

The Kernel Mixer is absent from Windows Vista, which features a revamped audio architecture. Windows Vista is a line of graphical operating systems used on personal computers, including home and business desktops, notebook computers, Tablet PCs, and media centers. ... Windows Vista (formerly codenamed Windows Longhorn) has many significant new features compared with previous Microsoft Windows versions, covering most aspects of the operating system. ...

DirectX Sound Libraries

Please refer to DirectSound, DirectSound3D, and DirectMusic DirectSound is software supplied by Microsoft that resides on a computer with the Windows operating system. ... DirectSound3D is an addition to Microsofts DirectX system which is intended to standardize 3D audio under Microsoft Windows. ... DirectMusic is a high-level set of objects, built on top of DirectSound, that allow you to play sound and music without needing to get quite as low-level as DirectSound. ...

External links

Contents

Audio Compression Manager

KMixer

Controversies

DirectX Sound Libraries

External links

See also