transcode filters

Hello,

D Richard Felker III wrote:

> > cshift - chroma lag shifter
> 
> What is chroma lag?

The chrominance component shifted to the left or right compared to
luminance. This seems to happen in some broadcast situations. Granted
this is not *widely* necessary.

> > decimate - NTSC decimation in pure software
> 
> What is NTSC decimation?

Removal of duplicate frames. Made as a part of the inverse telecine
process. MPlayer seems to have the whole process in one big whopping
filter (ivtc or detc); but heck, what if I need this stuff for other
purposes? 

Notably, some animation tends to have low real fps; like 15, sometimes
lower. While experimenting with decimate to capture only the meaningful
frames might be a long process, it may be worth the result.

> > smartdeinter/smartyuv - "smart" deinterlacing, only deinterlaces motion
> > areas and keeps the full resoultion in others
> 
> Similar to pp=md.

smartdeinter uses some thresholds (all tune-able) to detect motion
areas, and only applies a deinterlacing algorithm to where it has
detected motion.  (smartyuv is a yuv-optimized version of the same).

CPU-intensive, but can do wonders, especially if you spend some time
fine-tuning it. 

I'll have to encode some lectures soon; there the still part of the
image (the drawing pad) should be kept at max resolution, while the
moving part (the speaker) should be deinterlaced.

If I were to use mencoder instead of transcode, I'd lose all the
fine-tuning capability. Try pp=md, love it or leave it. 

Yours, Mikhail Ramendik