Suddenly i cannot load videos from you tube and some other locations, although I can load then using CHROME

Question

The problem is that all of a sudden, I cannot load and see videos from youtube and some other sites.
When I ask to see something from youtube for example, the appropriate page opens, and in the place that the video was supposed to be loaded, I see a black screen and nothing happens.
I scanned the computer and found nothing.
I uninstalled firefox and installed it again.
The problem stays.
I browsed using CHROME and I have no problem. i can see everything perfectly.
This happened suddenly today.

Answer 1

Could they be viewed ... and used ... by QuickTime Player?
Installing the Perian codec component package will normally allow FLV file containers to be played in QT players. However, it might be more helpful here if you could provide a specific YouTube URL (and resolution if applicable) of interest to check out. While I previously indicated content was typically converted to FLV, MP4 files may also be used and content may compressed as H.264/AAC in either container which, of course, should already be QT compatible without additional support.
Could anything be done about improving video quality?
That depends. If the file you are interested in is available in multiple resolutions, then downloading the highest available resolution would provide the best starting point for iMovie editing. If compressed content is already in an iMovie compatible compression format, then it might be possible to copy the content to an iMovie compatible file container (if not already in one) and thus avoid transcoding the data before import to iMovie. However, you still have the potential for some visual quality loss after editing when you export the finished project from iMovie.