Description

Is this really 12-bit video ?

How can you tell if you’re really producing 12-bit video?  Aside from a handful of DCI projectors, few displays can actually render in 12-bit color. Even if you found a proper 12-bit display, it would be challenging to visually tell the difference between 10 and 12 bit video.

With the introduction DNXHR 444 and the development on new mastering workflows, I wanted to analyse the video content of my files to ensure I was not losing video information in my pipeline. Also, since DNXHR is still a new codec, not all software has been updated to read the bit-rate metadata correctly. This can lead to confusion, not knowing what you’re actually working with.

With this 16-bit TIFF Test Pattern, you can actually test how different applications are affecting bit-depth and which transformation are being made. Here’s how to use the chart:

Import the TIFF in your video software, export your codec and then get the numerical RGB values for all 4 sections of the chart.
– In Resolve. you can use “Show RGB Picker Values”, but the values are limited to 8-bit or 10-bit.
– In After Effects, open the “Info” window and you can choose the cursor display RGB values of 8,10 or 16 bit per channels

The chart consists of 4 very similar grey values that are numerically different when processed at 12-bit or 16-bit, but get compressed when processed at 10-bit and 8-bit.

In 12-bit, 16-bit or 32-bit-float workspace, here’s what to look for:

If your video was processed as 16-bit or 12-bit, every column will have a different RGB value

If your video was processed as 10-bit, 2 columns will have the same RGB value

If your video was processed as 8-bit, all columns will have the same RGB value

Additionally, you can check for gamma shifts by comparing processed RGB numerical values to the RGB values of the original TIFF file.