Variable GOP Pattern

[dvdboy]

I've just run one of my CCE encodes through Bitrate Viewer, and it is telling me there is a "Variable GOP Pattern" showing GOPs ranging from 2 to 100 pictures in size. This is a little concerning, considering the GOP was set to 15 and closed!

Have I got a setting wrong, or is this how CCE does things?

[Jeffster]

CCE uses automatic scene change detection and will insert an I frame when it detects a new scene, which is generally a good thing. That is the reason for the variable GOP length. If you need all the GOP's to have a fixed length for some reason, then you must disable the auto scene change detection, just be aware that it may affect the quality if it is disabled.

Closing all GOP's may also affect image quality, but has nothing to do with the GOP length.

Something is wrong though if the GOP length has gone as high as 100 pictures but I would be inclined to think it's an error with Bitrate Viewer and not CCE.

[dvdboy]

Hi Jeffster,

I think you could be right, as I've just tried MPEG Validator, which is reporting everything as ok.

Very Strange..