[Ffmpeg-devel] cbp

Mike Melanson mike
Fri Mar 17 02:45:35 CET 2006

Marcel Wolf wrote:
> Guys
> WHat is the difference between cbpc cbpy and cbp? I thought the cbp was
> a bit definition of what blocks are non-zero (1=non-zero)? For example,
> the 6-bit value would indicate which block 0-5 is non-zero or 0x3f would
> be all non-zero. Is all this true and how are cbpc and cbpy different?

	Not sure what cbpc and cbpy are, exactly. I'm pretty sure the cbp 
values indicate which of the 6 constituent blocks of a macroblock are 
coded/changed in this frame (1) and which are unchanged from the 
previous frame (0).

> Also, what is gb below?

	gb is the GetBitsContext. It's an opaque data structure that you 
shouldn't have to worry about in FFmpeg.

	-Mike Melanson

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