I just finished reading an interesting article by Amir Majidimehr (former Microsoft VP, video compression) in Oct 2008 issue of Widescreen Review. I was surprised that there are 4 different, incompatible versions of MPEG-4! Here are some facts from the article; I recommending picking up a copy of the magazine for all of the details and background.
- MPEG-2 was created in 1993 and gave great improvements of JPEG.
- Real Video and Windows WMV-9 were alternative compression codecs created for internet video streaming and are about 200% to 300% more efficient than MPEG-2.
- The MPEG association wanted to get into this segment and created MPEG-4 (later known as MPEG-4 ASP.) It was terrible, only 30% more efficient than MPEG-2.
- The European Standards body ITU created H.264 and it was much better than MPEG-4 for internet steaming video. MPEG approached the ITU and they joined forces, creating the new MPEG-4 AVC, a.k.a. H.264 JVT, and it is completely different from and incompatible with the origianal MPEG-4 ASP.
- When HD-DVD was developed, MPEG-2, MPEG-4 AVC, and Microsoft WMV-9 (VC-1) were compared. For HD video VC-1 was the clear winner, MPEG-2 was second, and MPEG-4 AVC gave the lowest quality/compression.
- MPEG-4 AVC HP (High Profile) was created to overcome the problems with the original MPEG-4 AVC, which focused only on low bitrate steaming video. MPEG-4 AVC HP is what is in every Blu-Ray (and HD-DVD) player and it completely incompatible with MPEG-4 AVC.
- Every Blu-Ray player supports VC-1, MPEG-4 AVC HP, and MPEG-2.
- Microsoft seemed to have their act together throughout this process and developed the right codec for multiple situations from the beginning. It’s roughly equivalent to MPEG-4 AVC HP in quality but requires less processing power to decompress.