TMPGEnc - Average bitrate ends up too low

[aebbeka]

For some reason, files resulting from TMPGEnc Plus using VBR are smaller than they should be. In the past it has always gotten extremely close to the target bitrate, but now I can't get it close on any source. For example, I have it set to 7810 kbps, and it ends up being about 7400.

The only cause I can think of is that 7810 kbps isn't needed for the source I'm trying to encode, but I've done the same type of footage from the same source before, and it worked fine.

I found it hard to believe that 7810 kbps was more than necessary for slightly noisy VHS footage, so I ran a test using Constant Quality at 100%, and it ended up with an average bitrate close to the maximum. So the VBR isn't running at maxium quality.

Is there a setting anywhere that could possibly affect the average bitrate? I'm really stumped as to why it is suddenly doing this.

[bendixG15]

Are you reading video and audio ???

[aebbeka]

No, it's video only, going to an elementary stream.