- From: Harald Alvestrand <harald@alvestrand.no>
- Date: Fri, 12 Sep 2014 11:39:48 -0700
- To: public-media-capture@w3.org
On 09/11/2014 10:45 AM, cowwoc wrote: > On 11/09/2014 12:21 PM, bugzilla@jessica.w3.org wrote: >> https://www.w3.org/Bugs/Public/show_bug.cgi?id=26526 >> >> Jan-Ivar Bruaroey [:jib] <jib@mozilla.com> changed: >> >> What |Removed |Added >> ---------------------------------------------------------------------------- >> >> CC| |jib@mozilla.com >> >> --- Comment #3 from Jan-Ivar Bruaroey [:jib] <jib@mozilla.com> --- >> I think the existing epsilon covers inaccuracies in double just fine, >> and that >> arguments to change it were in the opposite direction, chasing the >> problem of >> interpreting expectations correctly of people entering decimals by hand. >> >> I believe Harald proposed 1/1000 [1], and I indicated perhaps 1/100 >> as being >> better, citing wikipedia [2] as evidence that accuracy-needs on >> aspect don't >> rise with higher resolutions. >> >> [1] >> http://lists.w3.org/Archives/Public/public-media-capture/2014Aug/0056.html >> [2] >> http://lists.w3.org/Archives/Public/public-media-capture/2014Aug/0084.html >> > > I believe your reasoning is still flawed. You shouldn't evaluate the > "goodness" of an epsilon by looking at a handful of resolutions as > you've done. You need to evaluate the epsilon against the entire > resolution space from 1x1 through 16k. > > For example, what happens when a user asks for an aspect ratio of > 8/12? He might be aiming for 800x1200 but you'll give him 788x1200 for > an epsilon of 1/100. That's a huge error margin. Interesting numbers you're using. 1/100 of 8/12 is 0.00666666666666 - so with an epsilon of 1/100, the acceptable range should be from 0.66 (exact) to 0.673333333 (repeating decimal). If the width is fixed at 1200, the acceptable range for height is from 792 to 808 pixels - half a macroblock. If the epsilon is 1000, the acceptable range is from 799.2 to 800.8 pixels. Not large. But I'm fine with sticking with Cullen's 10 digits. > > Gili > -- Surveillance is pervasive. Go Dark.
Received on Friday, 12 September 2014 18:40:25 UTC