
	Where results make sense

Topic: Variable bit rate

Related Topics

Constant bit rate

Bit rate

Bits per second

Data transfer rate

WMA

MP3

Codec

Audio codec

Lossless data compression

Data compression

Asynchronous Transfer Mode

In the News (Wed 2 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	RealJukebox FAQ - Constant and Variable Bit Rate Encoding
		In order to maintain constant bit rate throughout the file, difficult passages (for example, passages containing a relatively wide stereo separation), may be encoded with fewer than the optimum number of bits.
		Variable Bit Rate encoding was developed for use when consistent audio quality is the top priority and constant or predictable encoded MP3 file size is not critical.
		By maintaining a constant bit rate, you force the quality of the CBR operation to vary according to the complexity of the audio file.
	service.real.com /help/faq/rjbvbrfaq.html (765 words)

	Variable bit rate - Wikipedia, the free encyclopedia
		Variable bit rate (VBR) is a term used in telecommunications and computing that relates to sound or video quality.
		VBR allows a higher bit rate (and therefore more storage space) to be allocated to the more complex segments of sound files while less space is allocated to less complex segments.
		The average of these rates is calculated to produce an average bit rate for the file that will represent its overall sound quality.
	en.wikipedia.org /wiki/Variable_bit_rate (147 words)

	Variable bit rate - Wikipedia, the free encyclopedia (Site not responding. Last check: 2007-11-03)
		The term variable bit rate (VBR) is a term in telecommunications Quality of Service.
		When referring to codecs, variable bit rate encoding varies the amount of output data in each time segment based on the complexity of the input data in that segment.
		VBR is preferred for storage (as opposed to streaming) because it makes better use of storage space: More space is allocated to more complex segments while less space is allocated to less complex segments.
	www.encyclopedia-online.info /VBR (171 words)

	Constant bit rate - Wikipedia, the free encyclopedia
		Constant bit rate (CBR) is a term used in telecommunications, relating to the quality of service.
		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.
	en.wikipedia.org /wiki/Constant_bit_rate (200 words)

	(WO 01/06718) VARIABLE BIT RATE IN CIRCUIT SWITCH (Site not responding. Last check: 2007-11-03)
		Variable bit rate packets received in the interworking unit (6) are mapped to an internal format and sent through the connection (9).
		The variable bit rate traffic received at the pooled functionality device (8) is typically demultiplexed according to the channel number and synchronized, which transfers them into a constant bit rate fashion.
		Similarly, constant bit rate traffic may be packetized and sent over the connection (9) to the interworking unit (6) according to the internal variable bit rate format.
	www.wipo.int /ipdl/IPDL-CIMAGES/view/pct/getbykey5?KEY=01/06718.010125 (275 words)

	Service clock recovery for variable bit rate services - Patent 5204882
		To recover the service clock of a variable bit rate source (170) which generates data at a rate which is not proportional to a service clock (76), timing cells are generated.
		Because the rate at which information is written into the transmit-buffer at the transmit-end is proportional to the service clock, the service clock can be recovered at the receive-end by averaging the rate at which information is transferred from the receive-buffer to the receiving unit of customer premises equipment.
		Illustratively, the variable bit rate data is formatted into cells and both the data cells and timing cells are embedded in an Asynchronous Transfer Mode bit stream for transmission via a broadband trunk and exchange network to a receiving unit of customer premises equipment.
	www.freepatentsonline.com /5204882.html (6459 words)

	Bandwidth Allocation Strategies for Transporting Variable-Bit-Rate Video Traffic
		When the frame generation rate is constant (e.g., 30 frames/s in the NTSC format), the output of the encoder constitutes a variable bit rate (VBR) stream.
		In particular, the bit rate is strongly modulated by scene changes, which occur on a time scale of several seconds (hundreds of frames).
		Assume that frames are transported at a constant frame rate and that the bit rate during one frame period is constant (given in the number of ATM cells per frame period).
	www.comsoc.org /ci/private/1999/jan/Krunz.html (6111 words)

	AVS Forum - DVD recorders with variable bit rate recording?
		The average bit rate typically defines the recording mode and maximum recording duration for a disc.
		bit rate increments (recording duration can be set to the nearest minute, therefore, there are theoretically 6x60=3600 increments), depending on the recording duration you choose.
		For example, if you knew that recording rate X was the perfect quality to fill a DVD with your known-length show, you could record at rate X to the hard drive, and include some before/after time in case the show started a bit early, goes late, whatever.
	www.avsforum.com /avs-vb/printthread.php?t=530706 (3742 words)

	DVD Talk Forum - What is >> Variable bit rate?
		I was looking to bring the bit rate down to 128 instead of 192 when uploading cds.
		I always thought this meant varying the bit rates you use: 128, 160, 192, maybe some 320's.
		I tried the variable rate and it takes LAME wayyyyyyy to long to extract the WAV files this way.
	www.dvdtalk.com /forum/printthread.php?t=218466 (664 words)

	Two-pass MPEG-2 variable-bit-rate encoding
		To assign bit rates to specific segments of a video sequence such that we attain constant visual quality, it is optimal to have knowledge of the characteristics of the entire video.
		The bit allocation for the macroblocks in the second pass is done by lexicographically ordering all of the blocks over the entire sequence, but constrained by the buffer and channel requirements.
		The bit rate that is fitted to the data is derived from Table 2, for an average bit rate of 4 Mb/s.
	www.research.ibm.com /journal/rd/434/westerink.html (8477 words)

	United States Patent: 5,559,798
		Such a system is responsive to the rate at which new calls or requests for connections enter and leave the network, the frequency and duration of extended peak rate data bursts, as well as the occurrence of short duration data transmission peaks.
		In response, the rate value R.sub.0 (associated with the initial segment, S.sub.0, of the particular compressed video data program stored within video source 207) is transmitted from video data transmission rate memory 208 to network renegotiation controller 213.
		For a given service rate r.sub.i video pre-processor 218 is programmed to minimize costs employing a Viterbi-like process subject to the constraint of source buffer 206 having a size B, and b.sub.i is the amount of compressed video data that actually resides in source buffer during the transmission of interval i video.
	www.eecs.berkeley.edu /~dtse/rcbr2_patent.html (3770 words)

	IBM Journal of Research and Development: Single-pass constant- and variable-bit-rate MPEG-2 video compression (Site not responding. Last check: 2007-11-03)
		We propose a robust single-pass VBR video encoder algorithm which is capable of learning and adapting itself to the complexity of image segments and thereafter creating streams which have constant visual picture quality.
		By CBR we mean that the sustainable rate of the encoded video stream per GOP is close to a constant target rate, but the instantaneous rate changes per picture depending on picture type or the quantization sealer.
		VBR can be used for networks that employ a dynamic bandwidth, as in ATMs, or it can be exploited as a means of achieving statistical multiplexing for digital broadcast satellites.
	www.findarticles.com /p/articles/mi_qa3751/is_199907/ai_n8865318 (1450 words)

	VBR - Variable Bit Rate
		Variable Bit Rate - VBR is best for progressive download where you have some flexibility over the data rate at any given moment.
		Variable Bit Rate means the encoder can allow for some increase and decrease in data rate as needed and dictated by the settings you chose.
		You could get very different data rates with two different videos if one were talking heads and the other was fast action sports.
	www.flip4mac.com /glossary_VBR.htm (115 words)

	Question 9/16 - Variable bit rate coding of speech signals (Site not responding. Last check: 2007-11-03)
		A VBR encoder outputs a bit stream which may have a variable number of bits in successive frames.
		Bit rate may vary, for example, in large predefined increments/decrements or it may vary by as little as one bit resolution.
		The variability in bit rate may be either network controlled or source controlled according to the input audio signal.
	www.itu.int /ITU-T/2001-2004/com16/sg16-q9.html (552 words)

	Cisco - ATM Connection Configuration and Troubleshooting for the Cisco BPX 8600 Series Switch: VBR Connections
		Real time VBR connections are used to transport delay sensitive applications that may also exhibit bursty behavior, such as Voice Activity Detection (VAD) voice and data traffic in an ATM network.
		Non-real time VBR connections are used to transport bursty data that is not sensitive to variation in delay in an ATM network.
		VBR connections are policed on both Leaky Buckets.
	www.cisco.com /warp/public/74/atm_connection_vbr.html (898 words)

	Serving constant bit rate traffic in a broadband data switch - Patent 5150358
		Data from constant bit rate sources such as television cameras is entered into a group of queues.
		Analytic studies have shown that use of three queues for constant bit rate traffic and a fourth queue for variable bit rate traffic allows a high occupancy in the output channels to be maintained with a negligible number of data entities excessively delayed.
		The rate for this virtual channel is x and the type is constant bit rate or variable bit rate (action block 203).
	www.freepatentsonline.com /5150358.html (2532 words)

	Bit Rates When Encoding MP3 Files (Site not responding. Last check: 2007-11-03)
		In contrast, "variable bit rate" (VBR) encoding uses a dynamic algorithm whose bit rate at any point is based on "need" and varies as a function of the input sound source data values.
		When you do VBR encoding, you give the encoder program a "range" of bit rates (really just a specification of the maximum bit rate you will allow it to go up to) which you will permit it to vary across while performing the MP3 encoding.
		Depending on the source material, the encoded VBR result might be almost entirely at the maximum bit rate allowed (if the "variability" of the source is extremely high) or considerably less than that (if the source is much more "quiet" and "non-varying").
	www.scoug.com /os24u/2002/scoug202.mp3bitrates.html (1628 words)

	ITU-T Study Group 16 - Question 9/16 (Study Period 2005-2008)
		Hence, the work is to examine the applications, technical issues of IP and wireless networks, and investigate the design of a suitable variable bit rate voice coder.
		One possibility is a VBR encoder outputting a bit stream, which may have a variable number of bits in successive frames.
		Another possibility is an embedded encoder always outputting a bit stream consisting of several layers of significances, and either the network and/or the decoder can select the appropriate layers of coded signals considering the conditions of the transport network or quality of the speech desired.
	www.itu.int /ITU-T/studygroups/com16/sg16-q9.html (733 words)

	Codec description
		The sampling rate expressed in Hertz (Hz) is the number of samples taken from a signal per second.
		When encoding a speech signal, the bit-rate is defined as the number of bits per unit of time required to encode the speech.
		Variable bit-rate (VBR) allows a codec to change its bit-rate dynamically to adapt to the ``difficulty'' of the audio being encoded.
	www.speex.org /docs/manual/speex-manual/node4.html (1124 words)

	CD Ripper
		The higher the bit rate, the higher the quality of the MP3 and the file size is bigger.
		At this rate the quality is similar to a studio record and the compression is about ten times.
		It estimates the bit rate in such a way that the given quality(the previous parameter) is achieved for every single frame of the Mp3 file using a minimal bit rate.
	www.smartcdripper.com /features.htm (992 words)

	Slicing and Dicing MP3 bit rates
		To further complicate the bit rate game, many encoders allow you to customize the encoding process by selecting either constant or variable bit rates.
		And yet, Constant Bit Rate encoding pays no mind to all that and keeps its bit rate steady as she goes.
		It adapts the bit rate to the complexity of the audio, based on a scale you can set in the preferences of your encoder.
	www.digitalprosound.com /Htm/WebAudio/2000/Oct/MP3bitrates2.htm (705 words)

	Information Regarding Variable Bit Rate Encoding
		Variable Bit rate (VBR) encoding allows a user to guarantee a specified quality throughout the course of an encoding session.
		Content should only be encoded at a variable bit rate when it is intended to be downloaded and then played back locally.
		The buffer associated with variable bit rate content can be quite large making the start-up delay unacceptable for streaming scenarios.
	support.microsoft.com /kb/290545 (239 words)

	Free-Codecs.com :: Guides : VBR encoded MP3 files, advantages (and disadvantages?) - VBR stands for Variable Bit Rate.
		The bit rate of a coded audio file is the number of bits (binary digits - 0s or 1s - bits of digital information) that are required to store 1 second of audio.
		With variable bit rate MP3s, the encoder automatically detects which bit rate is most apropriate for the sound being encoded, live.
		This means that when there is little sound to be heard, the encoder encodes the MP3 with a low bit rate (as low as 16 kbps or less), but when there is very complex sound to be heard, the encoder uses a much higher bit rate (up to 320 kbps) to attain better sound reproduction.
	www.free-codecs.com /guides/VBR_encoded_MP3_files_advantages_and_disadvantages.htm (474 words)

	Understanding the Variable Bit Rate Real Time (VBR-rt) Service Category for ATM VCs [ATM Traffic Management] - ...
		The peak rate and average rate values implement traffic shaping on the ATM PVC.
		While both service classes place a bound on the cell delay variation or variability in the arrival of adjacent cells that make up the kbps rate of a VC, only CBR PVCs on some Cisco interfaces allow you to set a CDV.
		Configure the peak rate, average rate, and the burst cell size to perform traffic shaping.
	www.cisco.com /en/US/tech/tk39/tk51/technologies_tech_note09186a0080094cd0.shtml (1299 words)

	Visible Light : Expert Tips : Is Variable Bit Rate encoding really better?
		VBR encodes scenes with high motion at a higher bit rate than scenes with low motion.
		With bit rate calculations that are based on information constantly updated during the encode, VBR calculations may not be accurate for several minutes.
		Multi-pass VBR is available in some hardware encoders, requiring deck control to accurately run each pass.
	www.visiblelight.com /tips/vbr.aspx (335 words)

	DVD Talk Forum - What is >> Variable bit rate?
		Basically, it's supposed to use an intelligent 'algorithm' to judge where in each musical file more data, or bits, are needed.
		VBR is your best feaking friend when it comes to MP3 ripping.
		I think most of you are talking about ABR (average bit rate).
	www.dvdtalk.com /forum/showthread.php?t=218466 (808 words)

	Untitled Document (Site not responding. Last check: 2007-11-03)
		When encoding a feature film, a process called "variable bit rate" encoding is used, which allows complex scenes to use higher bit rates, while less complex scenes use lower bit rates.
		These bits are processed by the decoder on the video player.
		A variable bit rate allows complex scenes to use higher bit rates, while less complex scenes use lower bit rates.
	www.mightyatom.co.uk /mm/dvdglossary.html (586 words)

	iTunes 5 Brings Variable Bit Rate (VBR) AAC Encoding :: iPod Hacks :: The Latest and Greatest News and Info for Your ...
		One improvement that many may have missed (we have seen no discussion of it as yet) is the addition of variable bit rate (VBR) encoding for AAC files.
		With fixed bit rate encoding, every part of a track is encoded at the same bit rate, which is wasteful of disk space when you consider that, say, the thundering crescendo is a much more detailed sound than a period of almost total silence.
		Under VBR encoding, the encoder examines the type of audio that is about to be encoded and adjusts the actual bitrate used on that section of sound accordingly; for silence or simplistic waveforms the bitrate is lowered while, for complex areas of sound, a higher bitrate is used.
	www.ipodhacks.com /article.php?sid=1517 (1135 words)

Try your search on: Qwika (all wikis)