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Video buffering verifier
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<h2 id="operation-modes">Operation Modes</h2> <p>There are two operational modes of VBV: <i><a href="/facts/Constant_Bit_Rate/UHHb5Wfg">Constant Bit Rate</a></i> (CBR) and <i><a href="/facts/Variable_Bit_Rate/RrRLn4dl">Variable Bit Rate</a></i> (VBR). In CBR, the decoder's buffer is filled over time at a constant data rate. In VBR, the buffer is filled at a non-constant rate. In both cases, data is removed from the buffer in varying chunks, depending on the actual size of the coded frames. </p> <h2 id="standards">Standards</h2> <p>In the <a href="/facts/H.264/soCzKcmJ">H.264</a> and <a href="/facts/VC-1/KotHFF8I">VC-1</a> standards, the VBV is replaced with generalized version called <i>Hypothetical Reference Decoder</i> (HRD). </p> <ul><li><a href="http://www.bretl.com/mpeghtml/VBV.HTM">MPEG Tutorial - Video Buffering Verifier</a></li></ul>