Constant bitrate

Constant bitrate (CBR) is a term used in telecommunications, relating to the quality of service. Compare with variable bitrate.

When referring to codecs, constant bit rate encoding means that the rate at which a codec's output data should be consumed is constant. CBR is useful for streaming multimedia content on limited capacity channels since it is the maximum bit rate that matters, not the average, so CBR would be used to take advantage of all of the capacity. CBR would not be the optimal choice for storage as it would not allocate enough data for complex sections (resulting in degraded quality) while wasting data on simple sections.

The problem of not allocating enough data for complex sections could be solved by choosing a high bitrate (e.g., 256 kbit/s or 320 kbit/s) to ensure that there will be enough bits for the entire encoding process, though the size of the file at the end would be proportionally larger.

Most coding schemes such as Huffman coding or run-length encoding produce variable-length codes, making perfect CBR difficult to achieve. This is partly solved by varying the quantization (quality), and fully solved by the use of padding. (However, CBR is implied in a simple scheme like reducing all 16-bit audio samples to 8 bits.)

See also

• Bitrate
• Average bitrate
• Variable bitrate

This computer networking article is a stub. You can help Wikipedia by expanding it.v · Categories: Codecs Data transmission Computer network stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем сделать НИР Creatures (artificial life program) Sentō Look at other dictionaries: Constant bitrate — Pour les articles homonymes, voir CBR. Un Constant bitrate (ou Constant bit rate ou encore CBR), est un terme anglais que l on peut traduire en français par : « taux d échantillonnage fixe », en opposition au variable bitrate (VBR) …   Wikipédia en Français Constant Bit Rate — Constant bitrate Pour les articles homonymes, voir CBR. Sommaire 1 Définition 2 Calcul de l espace de stockage 3 …   Wikipédia en Français Constant bit rate — Constant bitrate Pour les articles homonymes, voir CBR. Sommaire 1 Définition 2 Calcul de l espace de stockage 3 …   Wikipédia en Français Constant rate factor — (CRF) is a x264 s single pass encoding method. Contents 1 Overview 2 Technical details 3 Not a common knowledge 4 See also …   Wikipedia Bitrate — Die Bitrate bezeichnet das Verhältnis einer Datenmenge zu einer Zeit, typischerweise gemessen in Bit pro Sekunde, abgekürzt als Bit/s oder bps. Sie bezeichnet die Ausgabemenge von Informationseinheiten bei digitalen, auf konstante Ausgabezeit… …   Deutsch Wikipedia Variable bitrate — (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. As opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment. VBR allows a higher bitrate… …   Wikipedia Average bitrate — refers to the average amount of data transferredper unit of time, usually measured per second. This is commonly referred to for digital music or video. An MP3 file, for example, that has an average bit rate of 128 kbit/s transfers, on average,… …   Wikipedia Variable bitrate — (ou Variable bit rate, ou encore VBR), est un terme anglais que l on peut traduire en français par : « taux d échantillonnage variable », en opposition au constant bitrate (CBR). Description Lorsque l on se réfère aux codecs, un… …   Wikipédia en Français VBR\/CBR\/ABR — T&F Variable bitrate (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. As opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment. VBR allows …   Audio and video glossary Comparison of video codecs — A video codec is software or a device that provides encoding and decoding which may or may not include the use of video compression and/or decompression for digital video. The compression may employ lossy data compression, so quality measurement… …   Wikipedia 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”