Linked by Thom Holwerda on Wed 14th Nov 2012 22:12 UTC
Internet Explorer "In Windows 8, we reimagined the browser with IE10. We designed and built IE10 to be the best way to experience the Web on Windows. With the IE10 Release Preview for Windows 7 consumers can now enjoy a fast and fluid Web with the updated IE10 engine on their Windows 7 devices. The release preview of IE10 on Windows 7 is available for download today."
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RE[5]: IE10 still disappointing
by lemur2 on Fri 16th Nov 2012 01:04 UTC in reply to "RE[4]: IE10 still disappointing"
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" WebM does take longer to encode than h264 at the same quality level, but that is its only penalty. If one chooses encoding profiles to yield the same quality level, the WebM codec actually ends up with slightly lower bandwidth (iow a slightly smaller filesize) than H264.

Have a WebM/H264 comparison to verify that?

Here's a fairly thorough one that puts x264 above WebM's standard encoder consistently, both in terms of quality and encoding speed (encoding speed seems to be about 3x faster for x264):

The comparisons you linked all compare a chosen profile of one codec against another. At some particular profile, one codec will be better than another ... but one can simply choose a higher profile for the second codec and it will be the other way around. The second codec at a higher profile will take longer to encode then the first profile chosen, but the resulting video will be better quality for the same filesize.

OK, so one can also choose a higher profile for the first codec, and now once again it will be better, once again at the cost of taking longer to encode. One can get a lot of combinations/comparisons this way, with each codec surpassing the other (in quality per bit) depending on the profile chosen.

There are multiple variables at play. Because the profiles are different for each codec, which profile to compare with which is somewhat an arbitrary choice. If one wants to make a reasonable comparison, one should eliminate at least one of the variables.

OK, so the best way to make a direct comparison between codec performance is what I alluded to in my original post. One chooses profiles for each codec such that they produce the same quality video at the same resolution and bitrate, and THEN one can compare the time to encode and the filesize.

If you do it that way, then WebM takes a lot longer to encode (to the same quality as a given profile of x264), but the resulting file size is a bit smaller.

Having said that, WebM time to encode is getting a lot smaller as the codec matures. The latest release (just over a week ago) is the fifth generation of the libvpx software (codename Eider) and sixth generation of the hardware (G1 decoder “Fairway” and the H1 encoder “Foxtail”). The first letter of the codenames indicate the generation since the inaugural release.

This new Nov 2012 release is probably at least two generations better than the version tested in the PDF file you linked. The gap in encoding speed (to the same quality of resulting video, with slightly smaller filesize) has probably narrowed considerably.

So, I repeat, the only penalty for using WebM is that it takes longer to encode. If the profile you are using for WebM gives you lesser quality than the one you have been using for x264, then simply choose a higher profile for WebM. Admittedly this choice will cost you in terms of the time taken to encode, but that time cost is the only penalty. Then again, it must be remembered that video is normally encoded once for many times that it is replayed, so if there must be one area of compromise, then encoding speed is the best area in which to take the penalty.

Edited 2012-11-16 01:08 UTC

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