Online HD Video's look incredible with Apple's Quicktime 7 Player which uses the new H.264 video codec.
Download Quicktime 7 Player:
http://www.apple.com/quicktime/download/standalone.html
Apple's HiDef Video Samples Gallery:
http://www.apple.com/quicktime/guide/hd/
About the H.264 Codec:
http://www.apple.com/quicktime/technologies/h264/
QuickTime 7 features a state-of-the-art video codec called H.264, which delivers stunning quality at remarkably low data rates. Ratified as part of the MPEG-4 standard (MPEG-4 Part 10), this ultra-efficient technology gives you excellent results across a broad range of bandwidths, from 3G for mobile devices to iChat AV for video conferencing to HD for broadcast and DVD.
H.264 in QuickTime 7: Under the Hood
H.264 in QuickTime 7 for Tiger implements a set of advanced technologies and patent-pending techniques to create pristine video at low data rates. The H.264 encoder features:
* Intelligent multi-pass encoding for the best possible results at the desired bit rate with the optimal number of compression passes.
* Time-saving single-pass encoding for creating draft encodes, meeting impending deadlines and live encoding with QuickTime Broadcaster.
* Peak-constrained VBR options for limited data-rate scenarios such as streaming and CD/DVD playback.
* Advanced frame reordering (B-frame) support to more efficiently represent movie data.
* 4x4 integer transform for reducing traditional blocking and ringing artifacts, especially in areas of fine detail.
* Improved intraframe prediction for more efficient compression of details and gradients in high-motion video.
* Increased precision in motion estimation for crisp reconstruction of objects in motion.
* Flexible block sizes in motion estimation for more efficient encoding of complicated motion in areas of fine detail.
* Adaptively tuned in-loop deblocking filter for eliminating blocking artifacts, resulting in a smooth, clean image.