4K TV Broadcasting is on the Way but There are Still Problems to Work Out
by Stephan Jukic – August 1st, 2014
Live 4K broadcasting shows an enormous amount of promise and early tests being conducted now are showing successful results but there are still aspects of the process that are creating some serious troubles for broadcasters and content makers.
So far, 4K has been trialed both over the air and over the Internet in its live form, and the largest single test to date has been the recent FIFA World Cup broadcast of the final game and two previous matches in live satellite transmitted 4K resolution to audiences in Europe and Asia. These live feeds were brought to the public by Sony, a plethora of cable and entertainment media companies and –in the Japanese case—by Japanese broadcasters working with Brazilian media companies.
While these broadcasts were enormous successes and massive promotional coups for 4K Ultra HD technology, they also demonstrated some unusual problems and roadblocks that will need to be overcome before 4K broadcasting can really take off widely.
One major problem with transmission to different types of 4K TVs became readily apparent when a number of UHD TVs from several different manufacturers were set up in the BT Corporation offices in Rio de Janeiro to catch the live 4K stream of the World Cup games that was also being beamed to Europe at the same time.
TVs from LG, Sony, Samsung, Panasonic and prototype set top boxes from companies such as Humax, Sagemcom and VIXS were also being used to catch and display the live Cup matches in Ultra HD.
What the results showed, according to those on the scene is that while the TVs and set-top boxes were all fed the exact same uniform content stream, not all UHD image processing is the same at all in the different TV brands.
One of the Panasonic screens, using experimental processing software ran at least 5 seconds behind the LG, Sony and Samsung screens while another TV with a VIXS set top box lagged behind by a full minute!
For live broadcasting, and especially of news and sports events, lags like these are completely unacceptable. However, the blame itself is difficult to assign. The HEVC decoding used in all of the TVs was of the same type, yet the lag times varied amongst the 4K sets that weren’t showing up to the second visuals of the Cup match. Various factors could have been at play, but the bottom line is that Live 4K broadcasting, even under such controlled, professional conditions still suffers from more glitches than would be normal.
More importantly still than problems in content processing of live 4K feeds is the issue of bandwidth requirements. IP delivery during the World Cup experiment required a full 36 Mbps of bandwidth for effective streaming of live content. Given that these were live broadcasts, the slightly larger transmission needs are understandable but even commercially viable non-live 4K streams are still requiring at least 20 to 25 Mbps in order to stream without lag and errors.
Netflix is one of the few companies that has ingeniously fixed these issues by successfully achieving 4K streaming through connections of just a measly 15 Mbps, but even here there is a problem for most web users since the majority of U.S and worldwide net connections are well below 10 Mbps, making live transmission of 4K still very tricky unless something more is done either on how UHD is encoded and compressed by broadcasters or unless ISPs really start bumping up their bandwidth services.
Finally, frames per second during the Experimental live broadcasts of the World Cup were delivered at a very nice, smooth 60 fps, and while this looked great, much smaller, more localized experiments in sending live action video at 100 to 120 fps are described as being spectacular, like looking through a window instead of an electronic screen.
However, again, firs the bandwidth issues and 4K stream processing problems need to be worked out before high fps 4K content becomes widespread.
Story by 4k.com