Doom9's Forum - View Single Post - How to evaluate the VBV-compliant CBR mode of X264?

drmpeg · 16th November 2013, 02:34

For analysis, it's very useful to graph things out. Here are some plots from an MPEG-2 encoder I used to work on. The bitstream is true CBR with an IPPPPP GOP. Looking at the running average, it can be seen that the CBR rate control is pretty "tight" (doesn't fluctuate much). The upward spikes are due to I-frame insertion at scene changes.

And a zoom in.

Ron

16th November 2013, 02:34	#10 \| Link
drmpeg Registered User Join Date: Jan 2003 Location: Silicon Valley Posts: 455	For analysis, it's very useful to graph things out. Here are some plots from an MPEG-2 encoder I used to work on. The bitstream is true CBR with an IPPPPP GOP. Looking at the running average, it can be seen that the CBR rate control is pretty "tight" (doesn't fluctuate much). The upward spikes are due to I-frame insertion at scene changes. And a zoom in. Ron __________________ HD MPEG-2 Test Patterns http://www.w6rz.net