Microsoft's VC-1 codec is superior without a doubt, if you think otherwise, then you haven't done your reading. So much so that, most of the newer Blu-Ray movies use the format. They had to so they could compete with HD-DVD's superior quality. Now, they are equal cause they both use primarily VC-1.
Not true. MPEG-4 avc & H624 and VC-1 are the same picture, it all depends on the content and implementation.
VC-1 Encoding
Profil & Level: AP@L3 except specific restrictions
Max GOP lenght: 14 frames
Maximum bitrate: 20.0 Mbps, 24.0 Mbps and 28.0 Mbps
Buffer size: 14745 Kbits for principal HD video stream
Horizontal Vector Range: unlimited
Vertical Vector Range: unlimited
Other Restrictions Setting: max adaptative GOP at 14, max adaptative bframe at 7
H264 Encoding
Profil & Level: HP@L4.1 except specific restrictions
Max GOP lenght: 14 frames
Maximum bitrate: 20.0 Mbps, 24.0 Mbps and 28.0 Mbps
Buffer size: 14745 Kbits for principal HD video stream
Horizontal Vector Range: +/- 1024 pixels
Vertical Vector Range: +/- 512 pixels
Other Restrictions Setting: max adaptative GOP at 14, max adaptative bframe at 7,
Max reference at 4, Max breference at 3, no film grain modeling
D - Conclusion
At this time for this movie
1) I use certainely the best MPEG2 encoder available in the area for metric: Libavcodec. The result is simply impressive for the old MPEG2 codec. With PP4 the result is even better. Libavcodec produce by far much better metric result here than all the other implementations (HCEnc, TMPGEnc, Mainconcept, Procoder ...).
2) VC1 is a very good surprise for me. For "low/medium bitrate" (high quantisation level) VC1 in unable to fight with H264 but for "High bitrate" the SSIM for VC1 is close to H264. MS say "VC1 is particulary optimized for high bitrate with high resolution" and it's true. Anyway MS claim that VC1 is able to produce the same metric that H264 but it's clearly false here.
3) H264 is simply the best for metric in all situation and particulary for "low bitrate" situation. Anyway differences between VC1 and H264 are not so high for low quantisation encoding.
4) VC1 and H264 at 6/20 Mbps (average bitrate/max bitrate) are unable to produce better quality than MPEG2 at 12/24 Mbps. H264 at 12/24 Mbps produce better quality than MPEG2 at 18/28 Mbps but not VC1. H264 at 12/24 Mbps is unable to produce better quality than VC1 at 18/28 Mbps. MicroSoft annonce ratio between 1:2 and 1:3 for MPEG2 vs VC1 but it's really not the case here. The x264 particularly optimized in its development to obtain very good PSNR is not able to obtain a ratio of 2:1 with MPEG2 in this challenge.
5) Use constrained vbv rate control produce very inconstant quality and use overall or average metric results in this case is very difficult because complex part (motion and/or texture) can produce very bad results for metric. For better results it will be better to use metric graph for part by part comparison. If a codec want produce good overall/average metric here then the codec must have particulary good vbv Rate Control optimization.
IF YOU DON'T AGREE WITH THAT, TRY WITH YOUR ENCODER ... !!!
http://forum.doom9.org/showthread.php?t=128498
EDIT: In my personal opinion, MS should have adopted MPEG-4avc/H264, but instead they make a proprietary hook codec that is used for MS products instead of using a universal code that is equally good, if not better.
