why does ffmpeg progress go to 1000+%?

[jsegel]

basically the topic title is my question. i'm converting a vob file to .mov. progress went quickly to 100%. that seemed reasonable, but it wasn't done. the progress bar in ffmpegx progress.app stayed at 100% and the numbers continue to climb. i'm at 1626% at the moment, cpu on my poor little g4 laptop at 100% itself! how can i ever tell how long this 11 minute movie will take to convert?

[Case]

The percentage is a simple calculation of how many minutes of movie have been converted divided by the duration of the clip. If it misread the duration of the clip, then the percentage will be off.
In theory, the program could do a more extensive test to determine the real duration. But with the current version, it keeps it simple by trusting the metadata, if present.
Especially VOB and MPG can be constructed by glued-together parts, where each part still has the duration in the header. Because of that, an 11 minute movie can easily be misread as 30 seconds. That in turn, can cause the percentage to climb to 2200%. If it was misread as 15 seconds, then the percentage could go up to 4400%.
The application MPEG Streamclip can fix "timecode breaks" in MPG and VOB files. One of the benefits is that the correct duration of clips will be read.