[mythtv] ffmpeg SWSCALE!
Yeasah Pell
yeasah at schwide.com
Thu Aug 31 04:00:59 UTC 2006
Michael T. Dean wrote:
> 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.
>
>
Mmmm. Interesting. You just had to go and kick it up one dimension,
didn't you? :-) I can certainly buy this explanation, though I'm having
difficulty visualizing the magnitude of it as a viewer. Intuitively it
seems like if it's primarily a temporal problem, a temporal filter would
be a reasonable solution -- but I'm well aware of the difficulties in
temporally filtering moving video (witness the complexity of good
deinterlacing)
> (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.)
>
Right, aliasing of that nature won't be helped by scaling up the image
anyway -- anything of that nature is a theoretically a source problem.
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