Can you render pure white? (#FFFFF or 255,255,255)

J

JaredSMark

Active member
I've done some tests lately and I'm thinking that it's impossible to render to pure white, I'm talking like #FFFFFF or 255,255,255. Every time I render a video that has pure white as the source (desktop recording for example), the color comes out to be #FEFEFE or 254,254,254. I'm using Adobe Premiere and exporting to h.264. I've tried this with both desktop recordings from Camtasia, and solid white backgrounds in Premiere.

Maybe this has something to do with the h.264 codec?
 
I just did a little more testing and the format doesn't really matter. I've tried various codecs in the Quicktime format (Video, Animation), h26, mpeg-2 and so on and it's all exporting to that weird 254,254,254 #FEFEFE color. Camtasia is doing the same thing too.
 
Legal values range from 1-254 for 8-bit video. 0 and 255 are not allowed. In 8 bit HD component video anything above the REC709 value limit of 235 is displayed as pure white, anything less than 16 as pure black. The range above and below those points are reserved for chroma overshoot in color signals to prevent overmodulation of RF transmission.
sRGB referenced RGB video codecs use the 1-254 range, but there is no visual difference between the two if monitors are properly calibrated for the slight difference in gamma reference.
Digital video codecs of any bit depth assign a scale of discrete values to an analog voltage range reference. For both REC709 HD and sRGB, the analog reference is the drive voltage range and color gamut for a C-standard phosphor CRT display as defined by NTSC standards. This is the range displayed on a video waveform monitor between 0 and 100 IRE.
 
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Does that mean the h.264 codec I'm using won't retain those 255 pure whites? It pushes them down to 254 I guess.
 
Derek Chingwell said:
Have you tried exporting as an image sequence or in an uncompressed avi format and checking values that way?
Click to expand...

I actually got it to work, but only when exporting to an uncompressed avi from After Effects and some kind of mainconcept mp4 from an old copy of Sony Vegas that I bought when I first started.

It's definitely a problem with the codecs I'm using. I was just unaware that a the standard h264 codec that we all use everyday did that until now.
 
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