RGB/B to RGB32

[vin97]

Is the conversion from RGB/B (TGA) to RGB32 (FFV1) via VirtualDub lossless?
If I am not mistaking RGB32 should preserve all information that RGB/B offers but I'm not 100% sure.

[jagabo]

What's RGB/B?

[vin97]

I gues I got trolled by Photoshop
Nevermind, using RGB was stupid anyways, I will stick to YV12.

[sanlyn]

All VirtualDub filters work in RGB. You can save the work in whatever colorspace you want, but the filters want RGB.

[vin97]

RGB takes much more space and time and I will have to convert the video to YV12 in the end anyways because I will upload it to YouTube.

The thing is though, when converting RGB/B to RGB32 theoretically no information should get lost because TGA files can only contain a maximum of 32 bits per pixel.

The TGA files are screenshots created by a game.

[jagabo]

TGA can only contain 24 bits of color. The extra 8 bits is an alpha channel, generally used as a transparency map. Both in RGB32 and 32 bit TGA. I don't know if VirtualDub preserves the alpha channel.

I still don't know what RGB/B is.

[poisondeathray]

The alpha channel is not preserved by vdub , but the alpha channel wouldn't be used in a screenshot for a game.

The alpha channel in this case is a "dummy" alpha channel - it's not used even though the data is stored as 32bpp . It's "32bpp" because 8R + 8G + 8B + 8A = 32bits per pixel, but only 24 are really useful. The dummy alpha actually takes up storage space (it can be compressed or discarded to 24bpp to save space)

I have no idea what RGB/B is either; I thought it was a typo supposed to be RGB/A

[sanlyn]

RGB takes much more space and time and I will have to convert the video to YV12 in the end anyways because I will upload it to YouTube.

The thing is though, when converting RGB/B to RGB32 theoretically no information should get lost because TGA files can only contain a maximum of 32 bits per pixel.

The TGA files are screenshots created by a game.

The only reason one would convert to RGB in VirtualDub is to use VirtualDub's filters, or to get into advanced masking and color correction in something like After Effects or Premiere. If you don't need that filtering work, you don't need RGB. If you're talking about data loss when you say "Lossy", the answer is no. Conversion between RGB color spaces isn't like lossy compression, although you might notice something about hues and whatnot looking somewhat different. Going fom one 24-bit to another 24-bit (effectively) RGB colorspace isn't a lossy process. If you go from 32-bit RGB to 24-bit RGB, you lose the transparency layer (which isn't used in final video output anyway).

Going from RGB to YUV loses some chroma resolution, but one could compensate for that somewhat if it's done with a better system like Avisynth's dither() or some other sophisticated means. I wouldn't do it in an NLE, their colorspace conversions are garbage.

[vin97]

Oh man, it's RGB/8, I think I should get glasses.
Anyways, I was being a little bit stupid.
Still thank you all for your answers.

[jagabo]

Oh man, it's RGB/8,

LOL. I looked all over trying to figure out what RGB/B was.

So, to answer you original question, there is no loss in converting to FFV1 RGB32 in VirtualDub as long as you don't force any colorspace conversions. It will create a dummy alpha channel (all zeros).