Parametric Stereo

Parametric Stereo

Parametric Stereo is a feature used in Advanced Audio Coding to further enhance efficiency in low bandwidth stereo media. It, along with spectral band replication (SBR), is part of HE-AAC v2. An HE-AAC v1 decoder will only give mono sound when decoding an AAC HE v2 bitstream.

Parametric Stereo performs sparse coding in the spatial domain, somewhat similar to what SBR does in the frequency domain.

An AAC HE v2 bitstream is obtained by downmixing the stereo audio to mono at the encoder along with 2-3 kbit/s of side info (the Parametric Stereo information) in order to describe the spatial intensity stereo generation and ambience regeneration at the decoder. By having the Parametric Stereo side info along with the mono audio stream, the decoder (player) can regenerate a faithful spatial approximation of the original stereo panorama at very low bitrates.

Because only one audio channel is transmitted, along with the parametric side info, a 24 kbit/s coded audio signal with Parametric Stereo will be substantially improved in quality, compared to a discretely stereo coded audio signal coded with conventional means. Thus, the additional bitrate spent on the single mono channel (combined with some PS side info) will improve the perceived quality substantially of the audio compared to a standard stereo stream at similar bitrate.

However, this technique is only useful at the lowest bitrates (say 16 - 32 kbit/s, sweet-spot at 24 kbit/s) to give a good stereo impression, so while it can improve perceived quality at very low bitrates, it generally does not achieve transparency, since simulating the stereo dynamics of the audio with the technique is limited and generally deteriorates perceived quality regardless of the bitrate.

External links

* [http://www.codingtechnologies.com/products/paraSter.htm Parametric Stereo at Coding Technologies]


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Parametric Stereo — (abgekürzt: PS) ist ein verlustbehaftetes Parametric Audio Coding Verfahren zur Audiodatenkompression von Stereo Signalen. Ein Parametric Stereo Encoder erstellt aus einem Stereo Eingangssignal ein Monosignal. Dazu speichert der Encoder für jeden …   Deutsch Wikipedia

  • Parametric Audio Coding — bezeichnet Audiokompressionsverfahren für ultraniedrige Bitraten. Technik Das Signal wird analysiert und in Objekte zerlegt, die mit Parametern beschrieben werden, aus denen auf Decoderseite wieder ein ähnlich klingendes Audiosignal synthetisiert …   Deutsch Wikipedia

  • Stéréo paramétrique — La stéréo paramétrique (en anglais : Parametric Stereo ou PS), est une fonctionnalité audio et un type d objet défini et utilisé dans MPEG 4 Part 3 (MPEG 4 Audio) destiné à renforcer l efficacité de codage dans les médias stéréo à faible… …   Wikipédia en Français

  • Parametrisches Stereo — (englisch Parametric Stereo, abgekürzt: PS) ist ein Verfahren parametrischer Audiokodierung zur verlustbehafteten Audiodatenkompression von Stereo Signalen. Ein parametrischer Stereo Encoder erstellt aus einem Stereo Eingangssignal ein… …   Deutsch Wikipedia

  • Advanced Audio Coding — AAC redirects here. For other uses, see AAC (disambiguation). Advanced Audio Codings iTunes standard AAC file icon Filename extension .m4a, .m4b, .m4p, .m4v, .m4r, .3gp, .mp4, .aac Internet media type audio/aac, audio/aacp, au …   Wikipedia

  • High-Efficiency Advanced Audio Coding — MIME audio/aacp, audio/3gpp, audio/3gpp2 Разработан ISO Тип формата Формат сжатия звука Содержится в 3GP, MP4, .dvb Расширен из AAC Стандарт(ы) ISO/IEC 14496 3 …   Википедия

  • HE-AAC — High Efficiency AAC (HE AAC) is a lossy data compression scheme for digital audio. It is an extension of Low Complexity AAC (AAC LC) optimized for low bitrate applications such as streaming audio. HE AAC version 1 (HE AAC v1) uses spectral band… …   Wikipedia

  • HE-AAC — Codificador avanzado de alta eficiencia Desarrollador ISO Información general Extensión de archivo .m4a Tipo de formato …   Wikipedia Español

  • Advanced Audio Coding — Pour les articles homonymes, voir AAC. Advanced Audio Coding Algorithme de compression audio …   Wikipédia en Français

  • Digital Radio Mondiale — (abbreviated DRM; mondiale being Italian and French for worldwide ) is a set of digital audio broadcasting technologies designed to work over the bands currently used for AM broadcasting, particularly shortwave. DRM can fit more channels than AM …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”