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[whatwg] Using <video> as a source for canvas.drawImage

From: Oliver Hunt <oliver@apple.com>
Date: Mon, 18 Aug 2008 16:24:44 -0700
Message-ID: <6E2DEA35-2EB3-48D6-B6A0-73215ADC38AD@apple.com>
Cool -- I wonder though if it would be better if it were placed in a  
different method, drawFrame or something (very much an up in the air  
sort of question)

One other thing that I would consider would be requiring the frame# to  
be specified explicitly as that would make things like "chapter"  
previews (or whatever) work in a way that is perhaps cleaner.   
Otherwise you have to record the current location in the video stream,  
then scan to each location you want to blit, draw, and then return to  
the original position.  Which could easily result in weird visual  
behaviour for the user (as the video element flickers a few random  
frames while you do your previews or whatever).

Just my 2c.

--Oliver

On Aug 18, 2008, at 2:45 PM, Robert O'Callahan wrote:

> Thanks to Anne for pointing this out...
>
> We've implemented using <video> elements as an image source in  
> canvas.drawImage:
> https://bugzilla.mozilla.org/show_bug.cgi?id=448674
> The extension is very obvious. Unlike animated images, which always  
> draw the first or poster frame, we draw the current frame of the  
> video. This lets you do things like make a thumbnail timeline.
>
> It'd be nice to have this in the spec.
>
> Rob
> -- 
> "He was pierced for our transgressions, he was crushed for our  
> iniquities; the punishment that brought us peace was upon him, and  
> by his wounds we are healed. We all, like sheep, have gone astray,  
> each of us has turned to his own way; and the LORD has laid on him  
> the iniquity of us all." [Isaiah 53:5-6]

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