Cleanup and improve efficiency of solid frame detection

[rnicholus]

[rverdel]

Hello rnicholus, Thank you for taking the time for this wonderful plugin. Just to let you know I had to make the variable "frameGrabInstance" a Global Variable in the onchange event for the file input. This way the onclick event for the button could access it.

[rnicholus]

You're quite welcome. Your approach is one option. Another is to include the click handler inside of the blob_to_video success handler, which is the preferred route in my opinion. I assume your comment is in reference to #7.

[rverdel]

Correct, this was initially for Issue #7. Oh, that is a good idea. Though I took the liberty of putting the function where the thumbnail(canvas) is appended in the blob_to_video handler and now when user selects the video file, a thumbnail is generated instantly.