On May 12, 2005, at 11:33 AM, Rich Felker wrote:
On Thu, May 12, 2005 at 11:09:08AM +0200, Michel Bardiaux wrote:
Sometimes my encoded movies show the infamous 'comb' effect (strong motion between the 2 fields). This of course could be due to the bttv, see below. I thought (mistakenly maybe) that the deinterlace filter was intended to compensate for the comb effect.
What you're calling the comb effect is simply the fact that you're putting two pictures together than don't go together. Deinterlacing effectively just throws away one of the two, or blurs the two together so you can't tell they don't go together.
That's bob/weave and it's stupid. The only remotely usable way to deinterlace is to shift the lines of one field into the other as neccessary. One deinterlacing method I've never seen described anywhere is to double the framerate instead. That's ofcourse wasteful, but with todays computers doubling the framerate is doable (it's just the output, the decode is still regular rate). Essentially you would convert e.g. 60i to 60p by only updating the new field (and perhaps dimming the previous field to simulate cathode ray phosphor fading). Anyone tried this? That should be as close to perfect as possible if the source is actually TV-sampled (and not pull-downed). /Roine