Video Preservation Web Site

Video Migration in the Preservation Laboratory

Digital Video Capture

8-bit, 10-bit and 14-bit Capture Options

In the following image, is an image capture from the same AJA Io System PDF, p 38; it defines some of the major advantage to using 10-bit capture of the analog video signal. 8-bit RGB has 256 steps for each of the red, blue and green channels, while 10-bit scaling has 1024 steps. This allows significantly more RGB values (steps) for the incoming signal to be divided into by the ADC.

The problem described on p 38-39 (below) is due to the natural compression of ITU-BT 601 (standard) video where the full 256 steps available in 8-bit digital scaling are reduced to 219 steps due to the definition of the ITU 601 standard. This is because of the blackest black is defined as RGB-step 235, rather than 255, and the whitest white is plateaued at RGB 16, rather than RGB 0; is is a range of (235-16) 219 RGB-steps, a significant compression. White the loss of RGB step in the whites is problematic, the loss of 19 steps in the dark is profound.