NHK, Japan’s public broadcast network, continues to shrink the size of both hardware and bandwidth required for Japan’s 2016 trial broadcasts in 8K Ultra HD. Working together with Astrodesign, the pair have managed to squeeze a 33-megapixel 8K sensor and all of its circuitry into a 10cm camera housing, weighing just 2kg.
“The image sensor is small, just 25 mm diagonally. So, the lens can be made small, too. In particular, this lens is used for digital cinema, but it’ll also be usable for Ultra HD. So, a feature of this system is, it can be made very small overall.”
“The monitor has 4K resolution, but the signal processing is 8K. The image sensor itself can run at 120 Hz, but the signal processing component isn’t ready yet. So here, the display is running at 60 Hz.”
NHK, in collaboration with Mitsubishi, has also developed the world’s first real-time 8K encoder. HEVC (H.265) is the next successor to today’s popular H.264 standard. HEVC will reduce the bit rate for encoded video by 50%, compared to H.264. In the demonstration, the HEVC encoder transforms a 30 Gbps RAW 8K signal into a slimmer 85 Mbps signal.
“This video is encoded at 85 Mbps. Considering the encoder input, it’s being compressed from 30 Gbps by a factor of 1/350. To encode Ultra HD video, which has very high resolution, encoding is done in real time by dividing the screen into 17 strips. Compression to 85 Mbps enables one Ultra HD channel to be transmitted using one satellite transponder.”
The encoder currently operates at 60 Hz, but NHK plans to develop a 120 Hz model to match Ultra HD specifications.
Andrew Michael is the Founder of Ultra HDTV Magazine. His interest in the technology began in 2008, before the term "Ultra HD" became mainstream. Andrew has contributed numerous articles, and continues to evolve Ultra HDTV into the ultimate Ultra High Definition resource.