Bitrates really high in H.264 files

[limeyx]

Hi,

I am converting some Final Cut Express (Apple Intermediate files in a Quicktime wrapper)
to H.264/mp4 for a playstation.

Everything works pretty good (Except ffmpegX seems not to be able to mux in audio for files over 2G)

but ...
I set the rate in the Video tab to 25000 kbit/s (which I think should be 25Mbps -- no ?)
Then I go to Options and set Qmin to 15 and Qmax to 30
Encode options are: Use CABC, constant bitrate, 2-pass encode, i4x4 analysis, Trellis, and Decode with Quicktime

On the PS3, I open the bitrate info and at certain points, the bitrates can exceed 200 Mbps! and frequently exceed 40 Mbps

Am I doing something wrong here ? The PS3 cannot decode at +200 Mbps so the video becomes very jerky in places.

[Case]

I set the rate in the Video tab to 25000 kbit/s

Why so high? H.264 doesn't need the high bitrates that e.g. DV needs.
For 1920x1080 (HD), 7282 kbps should be enough. For smaller frames (1280x720, 720x480, ...) the bitrate can be lower. Use the bitrate calculator to get a good value for your settings.

[limeyx]

I set the rate in the Video tab to 25000 kbit/s

Why so high? H.264 doesn't need the high bitrates that e.g. DV needs.
For 1920x1080 (HD), 7282 kbps should be enough. For smaller frames (1280x720, 720x480, ...) the bitrate can be lower. Use the bitrate calculator to get a good value for your settings.

Interesting. I just picked 25 (or somtimes 35) as the original HDV was 25 Mbps, and I know blu-ray can handle 25-35 Mbps

Still, I think the encoder ought to respect the rates I give it, no ?

[Case]

Still, I think the encoder ought to respect the rates I give it, no ?

I agree, even more so when using CBR.