interlace?

[Gildas Bazin]

On Mon, 6 Aug 2001 Christophe Massiot Wrote:
>
>Walken had a third solution. Doubling the stream frequency, and displaying
>50/60 fps, so that every field can be displayed at the right time (instead
>of 20 ms too early). With software YUV this is nearly impossible, but
>with overlay support, why not ?
>

The idea also crossed my mind, but I'm not really sure it's practical.

The goal is to create a progressive picture for each field and send this to the display.

But how do you create this progressive picture? I can see two solutions:

- you do some interpolation with the field you've got to fill in the gap left by the other field. This method will be either computer intensive or will produce artefacts (take for example a video with no motion, the interpolation done on each field is not likely to create the same picture).

- you leave one of the fields black in the progressive picture. I suppose this is the solution you were thinking about. The main problem here will come from rescaling. When you play a video on a computer screen, you almost always need to rescale it, if only to watch it fullscreen. But rescaling (or interpolating) a picture like this one won't work well.

To conclude, I suppose this solution could work, but you would have to forbid the user to change the size of the video when playing in window mode. And change the resolution of the computer screen when playing in fullscreen mode. I'm sure there would be other drawbacks (like added complexity of the code).

--
Gildas

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