One of the main reasons I went to NAB 2014 was to ascertain the state of UHD/4K standardization and the expected rollout timetable. Of course, the pixel resolution is well-established—3840x2160 for home-based systems—but what about other aspects such as higher dynamic range and bit depth, wider color gamut, less color subsampling, higher frame rate, encoding/compression and bitrate, and audio format? None of these parameters have been settled upon as part of a standard that content creators can follow and display manufacturers can implement.
I attended several presentations on UHD/4K, and the general consensus seemed to be that UHD is indeed coming to the home and that standardizing these elements was critical to its success. But how soon will that happen? Here's a timetable offered by Thierry Fautier of Harmonic, a video-infrastructure company.
The rollout of UHD is scheduled in phases. Notice that UHD-1 Phase 1, which we are in the middle of right now, specifies 4:2:0 color subsampling with 10-bit dynamic range, 50/60 Hz frame rate, HEVC codec, Rec.709 color gamut, and 5.1 audio, probably using current codecs such as Dolby Digital and AAC. High dynamic range is "preferred" but not required.
In particular, several presenters remarked that the most important element is high dynamic range, a sentiment with which I completely agree. Most people can't see the difference in detail between 1080p and 2160p on a 50" or 60" screen at a distance of 10 feet (a common scenario in today's homes), but everyone can immediately see the benefit of high dynamic range, even on a 1080p display. Some good news on that front was Dolby's announcement that the FilmLight Baselight color-grading system now incorporates Dolby Vision, allowing content to be graded for high dynamic range and wide color gamut. Now, all we need is for manufacturers like Vizio, Sharp, and TCL to make good on their CES announcements to build TVs with Dolby Vision capabilities.
Color gamut is another open question. Everyone was talking about how Rec.2020 includes a much wider gamut than the current Rec.709, but they also acknowledged that it would be difficult to make TVs that encompass that entire gamut, and that the DCI (Digital Cinema Initiative) P3 gamut might be more realistic, at least in the near term.
One interesting point to notice in the chart is that the video codec is specified to be HEVC, also known as H.265. In fact, I heard no one mention any other codec while I was at NAB. Some AVS members have asked about Google's VP9, which is likely to be used for YouTube UHD content. According to Wikipedia , VP9 can support 4:2:0, 4:2:2, and 4:4:4 color subsampling, and a profile that supports 10-bit dynamic range is under consideration, which implies that the current profiles are limited to 8-bit.
Another possibility is Sony's XAVC, which is a recording format that uses the highest level of AVC/H.264. According to Wikipedia , XAVC can support UHD/4K at up to 60 frames per second and all three common color-subsampling schemes at 8-, 10-, or 12-bit dynamic range. But other than Sony, no one was talking about anything but HEVC as the codec of choice for UHD content.
One thing was clear—UHD is not yet fully baked. At the show, I heard many people say that HDTV took 10 years to be fully implemented, so we should expect UHDTV to take about that long. I'm not sure I agree—after all, the pace of technological development generally increases over time, so perhaps the transition to UHD will take only five years. On the other hand, the standards will be decided by committees, which are notorious for taking inordinate amounts of time to reach any conclusions. In any event, this process will provide years of fodder for discussion, that's for sure.
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One of the main reasons I went to NAB 2014 was to ascertain the state of UHD/4K standardization and the expected rollout timetable. Of course, the pixel resolution is well-established—3840x2160 for home-based systems—but what about other aspects such as higher dynamic range and bit depth, wider color gamut, less color subsampling, higher frame rate, encoding/compression and bitrate, and audio format? None of these parameters have been settled upon as part of a standard that content creators can follow and display manufacturers can implement.
I attended several presentations on UHD/4K, and the general consensus seemed to be that UHD is indeed coming to the home and that standardizing these elements was critical to its success. But how soon will that happen? Here's a timetable offered by Thierry Fautier of Harmonic, a video-infrastructure company.
The rollout of UHD is scheduled in phases. Notice that UHD-1 Phase 1, which we are in the middle of right now, specifies 4:2:0 color subsampling with 10-bit dynamic range, 50/60 Hz frame rate, HEVC codec, Rec.709 color gamut, and 5.1 audio, probably using current codecs such as Dolby Digital and AAC. High dynamic range is "preferred" but not required.
In particular, several presenters remarked that the most important element is high dynamic range, a sentiment with which I completely agree. Most people can't see the difference in detail between 1080p and 2160p on a 50" or 60" screen at a distance of 10 feet (a common scenario in today's homes), but everyone can immediately see the benefit of high dynamic range, even on a 1080p display. Some good news on that front was Dolby's announcement that the FilmLight Baselight color-grading system now incorporates Dolby Vision, allowing content to be graded for high dynamic range and wide color gamut. Now, all we need is for manufacturers like Vizio, Sharp, and TCL to make good on their CES announcements to build TVs with Dolby Vision capabilities.
Color gamut is another open question. Everyone was talking about how Rec.2020 includes a much wider gamut than the current Rec.709, but they also acknowledged that it would be difficult to make TVs that encompass that entire gamut, and that the DCI (Digital Cinema Initiative) P3 gamut might be more realistic, at least in the near term.
One interesting point to notice in the chart is that the video codec is specified to be HEVC, also known as H.265. In fact, I heard no one mention any other codec while I was at NAB. Some AVS members have asked about Google's VP9, which is likely to be used for YouTube UHD content. According to Wikipedia , VP9 can support 4:2:0, 4:2:2, and 4:4:4 color subsampling, and a profile that supports 10-bit dynamic range is under consideration, which implies that the current profiles are limited to 8-bit.
Another possibility is Sony's XAVC, which is a recording format that uses the highest level of AVC/H.264. According to Wikipedia , XAVC can support UHD/4K at up to 60 frames per second and all three common color-subsampling schemes at 8-, 10-, or 12-bit dynamic range. But other than Sony, no one was talking about anything but HEVC as the codec of choice for UHD content.
One thing was clear—UHD is not yet fully baked. At the show, I heard many people say that HDTV took 10 years to be fully implemented, so we should expect UHDTV to take about that long. I'm not sure I agree—after all, the pace of technological development generally increases over time, so perhaps the transition to UHD will take only five years. On the other hand, the standards will be decided by committees, which are notorious for taking inordinate amounts of time to reach any conclusions. In any event, this process will provide years of fodder for discussion, that's for sure.
Like AVS Forum on Facebook
Follow AVS Forum on Twitter
+1 AVS Forum on Google+