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[12]: IE10 still disappointing
by saynte on Sat 17th Nov 2012 11:22 UTC in reply to "RE[11]: IE10 still disappointing"
saynte
Member since:
2007-12-10


With VBR, AFAIK the bitrate refers to the video as rendered, not the video as compressed. Because WebM static compression quality per bit is better than h264, and because most video is lower motion rather than higher motion, WebM can deliver a higher (as rendered) bitrate from the same number of as-compressed bits.


That's not what bitrate refers to.

The output bitrate is clearly constant: the number of bits per frame is just bit-depth*width*height (*fps to get bitrate). You don't change the bitdepth and dimensions of your video dynamically, as VBR would imply if it was the "output bitrate" that was being measured.

You wouldn't want your movie bigger and smaller as the bitrate changed.

WebM does not have higher quality/bit(rate), x264 does, and that's EXACTLY what those graphs in the study say.

Additionally the author of x264 has a great breakdown of the WebM/VP8 codec, basically the short side is: it's alright, misses some of the psy features (probably patented, blah) that H264 has.

http://x264dev.multimedia.cx/archives/377

This guy knows his stuff; even implemented a VP8 encoder, so I think his bias, if any, is pretty non-existant.

Reply Parent Score: 3

lemur2 Member since:
2007-02-17

The output bitrate is clearly constant: the number of bits per frame is just bit-depth*width*height (*fps to get bitrate). You don't change the bitdepth and dimensions of your video dynamically, as VBR would imply if it was the "output bitrate" that was being measured.


According to your definition, VBR doesn't exist, and it is not possible to have a video at a certain output bit-depth*width*height*fps with fewer bits.

Your definition is clearly nonsense. Variable Bitrate means the bitrate varies (even though the output bit-depth*width*height*fps does not).

Now if I only need a certain bitrate to get a certain quality for part of a video, and I actually use more bits, then am am using a higher bitrate, and I get better quality as a result. That is how it works, chum. The very graphs you keep referencing say so.

Edited 2012-11-18 07:42 UTC

Reply Parent Score: 2

saynte Member since:
2007-12-10

No, my definition allows VBR to exist, but it's clearly not used for the output bitrate, just the compression bitrate. You said that the bitrate refers to the "video as rendered", my explanation was to inform you as to why that couldn't be the case.

You're repeating something correct in the second half of your reply: that x264 has a higher quality/bit/second than WebM. I'm glad you got to the correct conclusion eventually.

Reply Parent Score: 2