filter/script idea

[Terka]

1080 consumer cameras output is not in fact containing all the 1080 lines, in bad light the carried information is even lower.
Is it possible by script determine how much information is in clip and suggest proper downsize?

[Groucho2004]

I usually step through some sequences using the statements below to determine whether it's worth keeping the high resolution (1080p).
As for commercial Blu Rays it's quite surprising how few deserve keeping the full resolution.

a = last
Spline36Resize(1280, 720).Spline36Resize(1920, 1080)
Interleave(a, last)

[Dogway]

Read this (http://ninofilm.net/blog/2010/04/26/full_hd_crop_zoom/). They do shitty conversions to comply to video what is supposed to be a photocamera. In this example the 5D II they skipped resolution lines in a not proportional way and in odd fragments, so it produces aliasing. But every camera and every company do their tricks to stamp a banner advertising it is able to record 1080p. It is safer to stay on 720p if you are not using a dedicated tool for video.

[Terka]

the question is how to fast way determine the 'real' resolution. im using panasonic sd600 and if there is a lot of motion or/and bad light, the record is washed out. so its nonsense to stay at 1080 in such cases. but go to 720? or less or more? how to decide, fast, accurate? could this be done by script that will do more resize, compare results and said use this resolution?

[Dogway]

the question is how to fast way determine the 'real' resolution. im using panasonic sd600...

well that's a video camera so it should be better. The fastest (and reliable) way wouldn't be resolution chart? and inspectioning the result carefully.

[Terka]

i was thinking about something like Groucho2004:
0. trim a part of video
1. filter like to be ready for final compress.

for different resolution do
{

if difference (original, dnup sized) > threshold
then print used downsize parameters, and exit

}
but how to write this in code?

(also think about downsize first, then filter.)