## B

backing object
  In multimedia streaming, the backing object is either the DirectDraw surface for video or the IAudioData object for audio.
bi-phase mark
  A method of encoding digital data within an analog signal. Bi-phase mark code is self-clocking (signal alternates on entry and exit) and not polarity conscious (identical values can be on top or bottom). Because it can be read over a wide range of play speeds, it is used for LTC signals. (originally known as Manchester-1 code).

blackburst
  A video signal that can be used to synchronize multiple video sources. Blackburst contains the vertical sync, horizontal sync, and the chroma burst information, but no active picture information.
blit
  Bit block transfer. Used to transfer all or part of a bitmap from a source such as memory or the screen, to a destination such as another memory or display surface.
bob
  A method of displaying interlaced video fields on a progressive monitor. See field for a more detailed description. See also weave.

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