ISDCF held another Plugfest this month, examining the playout of mixed content in a playlist, including high frame rate content. It was a worthy study, but by no means complete. This first pass proved quite valuable in observing the behavior of real equipment with complex playlists. If nothing else, it put to rest many of the concerns that people had. But there’s more to do.
Several playlists of real content comprised of 2D24, 3D24, 2D48, and 3D48 content, some with 5.1 and some with 7.1DS sound tracks, were viewed. The good news is that everything played. With some systems, glitches could be observed in between compositions, but they weren’t show stoppers and were unlikely to cause concern in audiences.
Booth technicians continue to note difficulties in setting up the various systems. Without a standard practice for macros and macro naming, it is up to operators to set up their macros to insure that content will show correctly. Admitedly, the Plugfest environment represents the worst case, as it operates with an impossible mix of systems. In a real cinema environment, only one or two makes of gear would have to be dealt with. But the point has been made that system manufacturers could make daily operations easier for cinema operators, particularly by pre-installing macros. Still early to sense if any action will really happen, but there could be a movement to supply commonly named macros with the systems to simply cinema operations.
One of the concerns for 3-D HFR content is that not all 3-D add-on systems can quickly respond to a change in frame rate. Wheel-based systems take time to adjust, in some cases up to 10 seconds. This Plugfest didn’t investigate this behavior, as only RealD was used for 3-D. More time spent observing different systems would be useful, if only to expose the true extent of the problem to a wider group of industry experts. For example, if booth technicians were having difficulty assembling playlists of mixed content for RealD 3-D, they might have even more problems when having to insert 10 seconds of black before and after trailers that force a wheel-based 3-D system to resychronize.
For the first time, this group was shown specially formatted 3D24 at the rate of 192 fps to the screen, producing “quad-flashed” 3-D on screen. It looked quite good. This wasn’t studied in a manner that would indicate if quad flash is notably better than triple flash. But it seems safe to say that it doesn’t look worse, which is the core concern. The interest in quad flash for 3D24 is that it can be implemented in a steady 96 fps from the media block to the projector. The projector, in turn, doubles that again into a 192 fps picture on screen. By doing so, 3-D add-on systems do not have to resynchronize each time the frame rate of the content changes. It would provide uniform results with any 3-D add-on system, which is ideal. Admittedly, this may not work well for 60 fps per eye content, and that case has yet to be studied for solutions.
The conclusion of ISDCF chairman Jerry Pierce is that the industry can do more to improve the playout of HFR trailers in playlists. That reference is to the difficulties encountered when assembling playlists, not to the less than perfect but still acceptable glitches between contents that were sometimes observed. The clear message is that there is more work to do, and ISDCF is encouraged to conduct more such valuable studies.