[mythtv] ffmpeg SWSCALE!

Michael T. Dean mtdean at thirdcontact.com
Thu Aug 31 02:52:11 UTC 2006


On 08/30/06 22:25, Yeasah Pell wrote:

>the question I was addressing is simply "do I need a greater resolution 
>discrete output device than my source signal in order to get the best 
>image possible from the source", not "is my CRT better than your LCD" or 
>anything else related to the specifics of any display device.
>
>The answer I came up with is "if you have a properly set up viewing 
>distance given your eyes and the size of the display device, you do not."
>
But remember that video is a sequence of images--each of which is 
reconstructed separately.  Therefore, aliasing in one image may not be 
exactly the same as aliasing in the following image (and the next and 
...).  This results in "flicker" (as in flickering pixels), which is 
definitely noticeable--even with your eyeball filters.  :)  Therefore, 
reducing aliasing is still important--even at HDTV resolutions.

(And this flicker doesn't even require geometric aliasing--i.e. an 
object whose size is small enough that it falls between samples in the 
image, and appears/disappears/reappears in different frames.  So, it can 
occur in a series of images whose resolutions are appropriate for the 
content represented therein.)

And, while I'm not saying that we'll see a huge difference when TV's are 
3840x2160 compared to 1920x1080 TV's, I am definitely saying there's a 
noticeable difference between a good 720x480 DVD displayed on a 1080p 
device and the same DVD displayed on a (much) lower-resolution device 
(i.e. a device whose resolution is on the order of the DVD 
resolution--it still looks pretty good on a 1280p device).  (I'm being 
very generic about the "other" device so I don't start new arguments 
about different technologies/different display properties/the color of 
the sky in my world/whatever.)

Mike


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