Quote:
Originally Posted by Rocinante
I'm in a third case scenarios now that due to a website streaming policy, they request a limit for a "maximum bitrate" value (such as all video max bitrate needs to be below 15Mb/s and below 8Mb/s average bitrate)
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That's exactly the "streaming" scenario. So, VBV is what you want/need here.
As said before, there is
no such thing as an "instantaneous" bitrate. Instead, a "bitrate" is always an
average, computed/measured over a certain time interval.
More precisely: Every picture has a certain size, in bits, in the encoded bitstream. And, whenever the decoder is about to start decoding the
next picture, we have to ensure that all bits required to decode
that picture already are present in the buffer. That's what VBV is all about! And that's also why "--maxrate" (i.e the network bandwidth, i.e. the max. rate at which the buffer can be filled) is
not useful
without knowing/setting the "--bufsize" (size of the buffer) as well.
See also:
https://pdfs.semanticscholar.org/830...807507dfed.pdf