Well, thank you guys for your posts. But I don't want you to expect too much from me. It took me about 6 months to make those Hewitt-Nalbandian highlights, mainly because of a lack of motivation and time. So, I can't promise anything.
And unfortunately I'm not a magician
, the quality just come from the quality of the original video...
About the program I used, for these particular highlights, that was Avidemux. But I have to say that I didn't find yet the perfect program to deal with H264. And sometimes Avidemux crashes with a file with no reason and I have to use something else like VirtualDub or H264TS_cutter or TSMuxer, etc.
To finish, here is the 1080p version of the Nalbandian vs Hewitt highlights : http://www.multiupload.com/2MH3HBGKHB
(I added all the details in my previous post