How to trim hdv (mpg) video clips at the borders of GOPs?

[suoiruc]

I am editing HDV with Mediastudio Pro 8.

I have learned that to avoid loss of quality Mediastudio re-encodes only those parts of the hdv (mpg) clips that have been somehow modified in the editing process. For example parts that include crossfade or other filters must be re-encoded.

I have got impression that if the clips begin or end at different location than the original borders of GOPs (only every 12th frame is a real key frame in hdv) also the additional frames must be re-encoded. And this can introduce unnecessary loss of quality between successive clips of the video.

Due to this I would like to edit my video so that all my cuts could be placed only at the original border of the GOPs (at the so called key frame of the GOP).

My questions are:
During trimming, is there any way to locate the borders of the GOPs? Is there any easy way to find just the real key frames (only every 12th frame) and to place cuts only at those points.

Thanks for all comments!

[toni1]

The only way to be accurate is ( I think ) to enlarge the timeline to the maximum size , then every one graduation is a GOP ( groupe of picture). anyway and to be honest; this the maimum triming precision you can get