<br><br><div class="gmail_quote">On Mon, Nov 17, 2008 at 2:32 PM, Philip Jägenstedt <span dir="ltr"><<a href="mailto:philipj@opera.com">philipj@opera.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I should point out that the pixelratio attribute isn't only for authors,<br>
it's also useful when the media framework used doesn't recognize the<br>
(pixel) aspect ratio even when it's correctly set. From reading the<br>
mplayer man page I see that AVI files can have aspect ratio set in the<br>
OpenDML vprp header, but I doubt e.g. DirectShow supports this (I could<br>
be wrong though).</blockquote><div><br>It does. You need to install a DS filter that supports the OpenDML based AVI 2.0. <br>But, we should probably focus on Media Foundation Transforms instead.<br><br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
I don't feel very strongly about the attribute either way, but given<br>
that video is scaled to fit inside its element box with aspect preserved<br>
and not simply stretched then an incorrectly parsed/guessed aspect ratio<br>
would make a big difference. </blockquote><div><br>Depending on how you want to accomplish you can do that with an enum<br>that defines how to handle the case:<br><br>1) do nothing.<br>2) disproportionately adjust<br>3) stretch follow by letter-,pillar-,windowbox appropriately.<br>
4) complete fill the screen and ignore overscan (ala pan & scan or zoom)<i><br><br></i></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
This seems very similar to the width/height<br>
attributes of an image and that usually isn't considered an ugly hack.<br>
If the pixelratio attribute is removed then I would suggest also<br>
removing the involvement of aspect ratio over the size of the element.</blockquote><div><br>on digital images, all you need is width/height. things like dot pitch, PPI and<br>DPI only play a roll when you are scanning/capture (analog to digital) or <br>
dealing with displays (digital to analog).<br><br>It is just that in video, to save bandwidth and avoid interference, they came out<br>with cool tricks such as interlacing, non-square pixels and odd frequencies.<br>Because of that, we are in this weird situation. I mean 59.94Hz is a perfect <br>
example of that.<br><br>Scaling and stretching and adjusting the aspect ratio are as much part of video<br>as they are part of images, it is just that you also need to worry how it aligns with<br>other sources, such as CC, Line 21 and audio. Just as the aspect ratio is a concern<br>
for images, it is a concern here.<br><br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
By the way, the "pixel-aspect-ratio" on video caps in the GStreamer<br>
framework has precisely the same meaning as this attribute, overriding<br>
it on a video sink also has an effect similar to what is suggested in<br>
the HTML5 spec. In other words, it's not so outlanding from a media<br>
framework's point of view.</blockquote><div><br>In the capture world it makes a lot of sense. You are converting analog content<br>into digital. It is my understanding that HTML5 is presentation technology, not<br>a video capture, transcoding or editing framework.<br>
<br>Also, note that in GStreamer it is expressed as a ratio, not a float ("1/1").<br><br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Oh, and if the video also needs cropping to get the correct aperture,<br>
couldn't this be done with CSS perhaps?</blockquote><div><br>Wow. How would you know how much to crop for each video clip? Wouldn't<br>specifying the enum above do the trick? <br></div></div><br>-- <br>Sander van Zoest <a href="mailto:sander@vanzoest.com">sander@vanzoest.com</a><br>
San Diego, CA, USA <a href="http://Sander.vanZoest.com/">http://Sander.vanZoest.com/</a><br><br>