DVD to DVD: YV12 to RGB to YV12, color problem ???

[cd090580]

Hi,

This weekeng, I've made a small video on a dark room with a mini dvd camera.

All is OK but I'd like to reduce a little the noise (not a lot). I've found the "Camcorder color denoise" filter for virtualdub.

But to use it I need to convert my video to rgb then back to yv12 for mpeg encoding ? Will the colors be damaged by such a conversion ?

I do it with avisynth the following way:

loadvirtualdubplugin("ccd.vdf","CamCorderDenoise")
v1 = mpeg2source("chapter1.vob")
v2 = mpeg2source("chapter2.vob")
v3 = mpeg2source("chapter3.vob")
...
#transition between each clip
Fullvid = Dissolve(v1, (dissolve(v2,v3,30), 30)
Fullvid.convertotorgb32()
even = separatefields.selecteven().CamCorderDenoise(10)
odd = separatefields.selectodd().CamCorderDenoise(10)
interleave(even,odd)
weave()
#maybe I will let the encoder to the conversion
converttoyv12()

Does my color space will remain correct ?????

Is there a way to do a loop if I add more clips for the dissolve function ?????

Thanks

[cd090580]

Is it Ok they way I do my video processing (color space conversion) ??????

My target encoder will be either Tmpg Mpeg Encoder Xpress 4 or CCE SP.

[jagabo]

Convertion to RGB will lose blacker-than-black (luma < 16) and whiter-than-white (luma > 235). The colors in between will lose a little accuracy though this won't often be visible without very close inspection.

If your video contains luma outside the 16-235 range you could use the PC.601 matrix to retain those portions:

ConvertToRGB32(matrix="PC.601")
...
ConvertToYV12(matrix="PC.601")

[edDV]

Hi,

This weekeng, I've made a small video on a dark room with a mini dvd camera.

Consumer camcorders usually use the full 16-255 range. Shooting in a dark room may limit 235-255 excursions but if there is a lit area, expect Y clipping.

[cd090580]

Ok, so it's best to use ConvertToRGB32(matrix="PC.601") ?????

My sources are PAL videos.

[edDV]

It depends whether your video contains 236-255 Y overshoots.

[cd090580]

Ok, and how can I see that ?

[jagabo]

VideoScope() or Histogram()

[cd090580]

Ok, yes I saw some clipping at the areas where the sun was shining (ie: ray of sun pases through a window and light the ground) and give then a high contrast

Will it damage a lot if I convert to RGB ?

Do I need to keep standard settings in CCE or Tmpg Xpress or is there some special tweaks too ?
Thanks

[jagabo]

Will it damage a lot if I convert to RGB ?

Why don't you compare for yourself?