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[whatwg] video tag: pixel aspect ratio

From: Sander van Zoest <sander@vanzoest.com>
Date: Tue, 14 Oct 2008 09:39:05 -0700
Message-ID: <98c2a8300810140939g48734d2cw7837ee568ab27255@mail.gmail.com>
Hi,

I just recently started looking at HTML5 and noticed the video tag. Neat
addition.
I also noticed that it as an attribute named 'pixelratio', however, as you
know this
is never an integer, but rather is the result of a fraction (i.e. ratio). As
for proper
playback of video frames, it is important to understand exact float and
therefore
I would suggest either expressing it as a ratio of two 32-bit integers
separated by a colon (or slash) or use two
different attributes. This avoids unintentional rounding.

Something roughly along the lines of:

<video pixelratio="10:11"> <!-- 525 composite NTSC -->
<video pixelratio="59:54"> <!-- 625 composite PAL -->
<video pixelratio="1018:1062"> <!-- 1920x1035 HDTV SMPTE RP 187-1995 -->

<video parhSpacing="10" parvSpacing=11">

Container formats tend to store this information in a ratio like this and
not in a float.

Best,

-- 
Sander van Zoest
sander at vanzoest.com
San Diego, CA, USA
http://Sander.vanZoest.com/
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