"Bitrate Too High" Errors with ffmpeg and DVDSP (3

[dayne33]

Over the last year or so I have been burning a fair amount of DVD's, and from both your comments major and my own observations, I have concluded that using the ffmpeg codec to encode mpeg2 files yields a higher quality end result (albeit marginal in some cases).

The problem is, most time when I encode files using the ffmpeg mpeg-2 settings, the video bitrate skyrockets (let's say, on average, for 2-3 frames, not sequential) to some value way over the average bitrate (as high as 9-10,000 kb/s).

To try to counteract this problem I have messed around with the qmin/qmax settings (Usually aim for 2-15, but have had to go up as high as 2-30).

Although rare, there were at least one or two cases where I had the qmin/qmax setting set at 2-30 and still got a bitrate spike.

Basically, I'm wondering if there is something I can do to avoid these problems in the future. Is it simply a matter of having to set qmin/qmax to 2-32 each time just to be safe, or is it something else?

Some info in case you need it:

Avg bitrate: Usually between 3900 and 4200 kb/s
Framerate: 29.97 (Even when source matertial is NTSC FILM, as I switched over to using mpeg2enc codec for DVD burning, so I have not fiddled around with using ffmpeg then performing a pulldown of the encoded files)
Filters: None
Options: High Quality, 4 Motion Vectors, 2-Pass Encoding, Trellis Quantization, Quarter Pixel Motion Estimation, Decode with Quicktime
Keyframe Interval: 12-15
Qmin/Qmax: Same as previously mentioned

I hope that's all you guys need. Thanks a lot.

[major]

The bitrate peaks are a well known problem of the ffmpeg mpeg-2 encoder, though most players will handle them very well. This should improve somewhen. For now if your player is really picky you must switch to mpeg2enc which has a more stable bitrate control.

[dayne33]

Ok, thanks a lot