What's exact the problem with Quicktime Player, problems with the download or with installing?
For playing in the browser: Try QT Lite.
Local player alternatives (after download):
a) Try Quicktime Alternative, which is the MediaPlayer Classic with Quicktime Codecs 188.8.131.52.
b) Get ffdshow. It's a media decoder which encodes almost every codec. Once installed every player uses it. I can play every type of video with every player on my computer.
c) Get VLC as additional player. It has an integrated encoder and plays everything. If VLC doesn't play it, the video should be corrupt. But I use it only in addition, my main player is MediaPlayer Classic, there I like more the user interface und controls.