How to control x264 min and max bitrate in 2pass vbr?

[pwnsweet]

Does anyone know how to control the minimum and maximum bitrate x264 can use in a 2pass vbr encode?

I want to convert a 1080p Blu-ray to a 720p 4.36gb mp4 so it will fit on a DVD5. I've done the encode, and I'm generally happy with the quality but have noticed that some scenes are getting too little bitrate. I'd like to re-encode the movie and sacrifice some quality in the scenes that are getting heaps of bitrate so that the other scenes look a little better.

Is there a way to do this?

[space1999]

Maybe this way :

http://mewiki.project357.com/wiki/X264_Settings#zones

[pwnsweet]

Thanks for the reply sapce1999. Whilst that may be a solution, I think you'd agree that it's a tedious one. While it's true that I would like to solve this problem, I'm not sure I want to enough to have to manually specify which range of frames the problem areas fall between and allocate higher quality settings to those areas.

Surely there's at least a way to specify max bitrate? This would go at least some way to helping mitigate the issue. I was experimenting earlier with TMPGEnc 5 (I'm using MeGUI/Ripbot264 for my encodes) and that program has a max bitrate control. Unfortunately it has no advanced options such as b-pyramid.

[nurbs]

You can set VBV values for maximum bitrate and buffer size. You should note though that vbv-maxrate isn't the maximum bitrate of the video, but the maximum rate at which the video can be read from the disk. The effective maximum bitrate can reach roughly maxrate + bufsize.

[GodofaGap]

I want to convert a 1080p Blu-ray to a 720p 4.36gb mp4 so it will fit on a DVD5. I've done the encode, and I'm generally happy with the quality but have noticed that some scenes are getting too little bitrate.
Did you verify this with a bitrate viewer? Blindly enforcing a maxrate can make the situation worse, or have simply no effect at all. Anyway, if the bit-allocation mechanism rates the specific scene as simple, it will still do so whether you enforce a max/min rate or not, so zones is really the best option you have.