Sometimes image becames blurry (out of focus) - need autosharpen filter

[Rush_iam]

Hello! I am new here and want your help.

I am recording video with a simple digital camera (not camcorder).
And this camera have problems with autofocus - it often loses focus and image becames blurry for some seconds.

I know that there are a lot of sharpen-filters which applies to whole video.
Is there any filters which will sharpen only when it needed? (that will turns on when image seems too blurry and turns off when image is sharp enough)

Thank you for your answers.

[Youka]

Cannot imagine that there's a filter that scans the whole image and decides 'Is it blurred? Is it the original or recorders fault?'.

[Rush_iam]

I think that it is possible to measure overall sharpness of image.
It should work like "auto white balance" or "autolevels" which corrects picture when needed...