YouTube is to support high dynamic range (HDR) videos. It’s a soft launch to say the least with just four videos uploaded to start with.
HDR in video is not the same as the more established technology of the same name in stills photography which involves combining multiple images shot with different range exposures and produces an image that doesn’t need any special technology to display.
Instead, video HDR is more about the way a video is displayed rather than captured. It involves a heavily increased contrast ratio, meaning more degrees of light and dark. The result is both a wider range of available colors and an effect where appropriate parts of the image appear brighter and can feel more lifelike. The way the images are coded for digital display also creates the potential for more detailed images depending on how they are produced.
The image above from Google is a simulation of the degree of difference HDR can make, though as always with video technologies that aren’t widespread it’s something of a thought experiment. In effect, Google is implying that HDR is clearer than the right-hand image to the same degree that the right-hand image is clearer than the left-hand image.
Google says the new clips will work on compatible hardware such as the Chromecast Ultra and Samsung’s UHD/SUHD television sets. While the likes of Netflix already offer some HDR content, the theory is that opening it up to the public could promote the technology and encourage more experimentation with the format among video makers.
All HDR clips on YouTube will also be available to play in ordinary “standard dynamic range” format, though they’ll be automatically down-converted. Google has warned that this downgrading won’t always make for the most effective results and could produce unnatural appearances, so video makers may prefer to produce their own alternative file.