Quote:
Originally Posted by benwaggoner
The BBIBB... pattern is either Open GOP (with the leading Bs referencing the prior GOP) or RADL, which references only following frames in playback order, but can reference more than one future frame. Open GOP is generally used with files and on optical disc, while RADL can be used with stream switching.
B-frames have ALWAYS used both forward and backward prediction, and thus at least 2 frames, all the way back to MPEG-1. Older codecs like MPEG-1/2 and VC-1 supported 2 reference frames for B-frames while allowing only 1 reference for P-frames. The resulting improvement in compression efficiency from the bidirectional prediction making B-frames smaller is a key motivation for B-frames in the first place (they also reduced cumulative drift due to different floating point implementations in MPEG-1/2).
The x264/x265 --ref syntax is dumb as it means different things with and without B-frames. It should really follow the bitstream syntax parameter, so the max ref frames is the same with and without B-frames
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So, please explain the reference of the first two B-frames of this
sample and show me how we can do this by x264 , Etc.
StreamEye says the only reference for both is the first IDR.
Note: I'm talking about the first 2 B-frames , not the rest of the stream.