Please Check My Levels

[meldavid]

I've setup a capture system using an old handycam to capture movies/shows from our Foxtel unit. I had to cut and strip an S-Video cable and terminate 2 of the wires with a 75 ohm resistor and used it with a Scart-to-S-Video adapter to feed AV into the camera's line inputs. Without the custom cable, the colours looked totally wrong. No way am I going to record using Composite!
A firewire cable connects the camera to a laptop so I can record the DV stream straight to a hard disk.

What I am unsure of is if I have to do any levels correction. I don't know if my captured DV AVI footage uses luminance levels of 0-255 or 16-235. I've encoded the movie twice: Once with no levels correction and once with the AVISynth line

ColorYUV(levels="TV->PC")

. I just need you to look at some screenshots and tell me which looks more correct. I chose to capture a well-known movie so you can easily tell as if the colours and levels look wrong.

I had a comment from my brother that the movie had a different feel so there must be something wrong with the colours or luminance levels. He likes the darker movie as it hid the blocky artefacts more but I think there is less detail.

Maybe also, I've just stuffed up the custom cable I made. I couldn't find a 75 ohm resistor so I chained 3 of them to roughly make up 75 Ohm but I don't think it would matter if I am off +- 5 ohms, would it?

Anyway just check these screens and make some comments.

[manono]

Hi-

I can't answer your main question, but:

I don't know if my captured DV AVI footage uses luminance levels of 0-255 or 16-235.

Just add:

ColorYUV(Analyze=True)

to a basic unfiltered script, open it in VDub, and scroll around. Check the Luma Y min and max values. My guess is that 0-255 is being used.

[meldavid]

Yes you are right. Min values reached 0 and Max values reached 255 occasionally so that means my capture is already in the PC scale and I don't need to use ColorYUV(levels="TV->PC") when converting to Xvid or when importing into CCE.

When I used ColorYUV(levels="TV->PC"), the Min/Max values were reached too often so blacks were deeper black at the cost of shadow detail and contrast increased too much.

[tarrickb]

the videos on the left had crushed blacks.
Therefore, I conclude the capture on the right is the correct ones.