halving the size and deinterlacing

[adom]

original is 1080i50, destination must be 800x480 max. 25fps. (xvid in avi/mp4)

the way I do it is:
get rid of one field then crop and scale to destination.

Question:
which way would give better result: dropping fields (above) or using deinterlace.

I'm asking because it will take me a while to find out correct syntax for mencoder.

[aedipuss]

1080i50 is interlaced 25fps(50 fields per second). dropping fields loses half the vertical resolution. what you should be doing is de-interlacing to 25p. try yadif.

[jagabo]

A good deinterlacer will usually give better results. But simply dropping one field often gives acceptable results. It depends on how sharp the video is and how many near horizontal edges there are.

[adom]

ok thanks - I'll try deinterlace with yadif right away (but it'll be probably much slower than dropping)

And I hope that -ofps will "take out" every 2nd frame from yadif.

The video is not sharp - it was recorded from mtv and they do not broadcast in good quality (but it is not what they say

[aedipuss]

you don't need to remove every other frame with a de-interlacer. it will take the top and bottom fields of a frame and combine them so your 50i will be 25p when done. and yes it's much slower than discarding fields.

[manono]

Well, Yadif is probably one of the fastest decent deinterlacers. Not as good as a really good (but really slow) deinterlacer, but plenty fast.

[adom]

I managed to make a command with yadif and it ran about twice slower then discarding fields - and with 2 passes it was noticable
The result is almost the same (for my eye) so I'll stick with discarding method.

Thanks.