Can you help to correct ColorYUV in this script?

[Bencuri]

There is a script that some of you suggested to convert my FullHD videos to DVD format in the past (1080 25p to 25p PAL). Back then a line with ColorYUV was added, but I am not sure about its functionality. I know we needed to modify the brightness, that's why the gain parameter was added I gess. But in my recent project, I don't have problem with brightness, so I wonder if I can omit that entire line, or should change it to something like: ColorYUV() ? Does that line have any significance besides changing brightness? The input is YUY anyway, as it was in the past when the script was suggested.

Here is the code:

AviSource("C:\Users\Videos\video.avi")
AssumeFPS(25)
Spline16Resize(720,576)
ColorYUV(gain_y=-25)
ColorMatrix(mode="rec.709->rec.601") 
ConvertToYV12()

[jagabo]

Nobody can tell you if it's needed or not without a video sample. ColorYUV(gain_y=-25) darkens all pixels by about 10 percent. If you don't need to darken the picture leave the line out. Or change the value to get the brightness you want.

http://avisynth.nl/index.php/ColorYUV

[Bencuri]

Nobody can tell you if it's needed or not without a video sample. ColorYUV(gain_y=-25) darkens all pixels by about 10 percent. If you don't need to darken the picture leave the line out. Or change the value to get the brightness you want.

http://avisynth.nl/index.php/ColorYUV

For the recent video no brightness correction is required. I just thought ColorYUV may also have a role to convert color from YUY to YUV, that's why it was added, and that's why I am asking now.