ISDCF conducted another 2-day Plugfest on September 26th and 27th. In this event, on-screen and off-screen captions were evaluated for synchronization with burned in captions, and for standards compliance through playout of the evolving and well-named Killer Reel produced by Fox. Not all media blocks render captions, as some rely on the TI projector to perform the rendering. Products that were evaluated were the Doremi IMB, Barco (XDC) server, GDC server, and the TI projector rendering engine. Also evaluated was the ability of servers to redirect SMPTE 429-2 Annex A audio to the correct outputs. There are no test scores, and for privacy reasons, there are no public write-ups that describe the performance of each product. However, this was a milestone event, if only because it caused the group to take a very mature view of where the industry is in terms of readiness of upgrades for SMPTE DCP distributions.
The tests conducted were quite harsh. In some cases, it can be (and was) argued that the tests are too harsh, in that they reveal artifacts that have little value in real world theatrical performance. A casual observation of the results on and off screen could lead one to believe that the industry has a long way to go to achieve a uniform ability to present timed text. Tests were constructed that caused one closed caption system to completely fail after 1 minute, for example. However, the cause of failure was not due to a problem found in actual distributions, and if meaningful failure modes were waiting to be uncovered, they weren’t going to be exposed in this Plugfest. Likewise, on-screen subtitle performance indicated a number of failure points. But on closer examination, the actual areas where a manufacturer could be shown where improvement was needed were few. As a self-evaluation of how meaningful the problems uncovered were, it was agreed that the devices viewed probably performed better than any device would with an Interop DCP. In other words, in terms of subtitle/caption performance, the industry is doing well.
If a finger can be pointed for not taking standards seriously, it is at TI and its in-projector text rendering engine. Over nearly a year of Plugfest demonstrations, TI has not been able to demonstrate a full implementation of the SMPTE Subtitle standard. In spite of the fact that industry participants through a collaborative effort within SMPTE decided on the details of the final standard, TI argues that a full implementation of the standard is not necessary. TI is right that its partial implementation will present text on screen. But the “TI knows best” snub of standards is not commendable. Since the introduction of the Series 2 projector, TI’s has encouraged in-projector media block developers put the text rendering engine in the media block. But some IMB developers prefer to leave this expense out of their work. While there are pros and cons, text rendering in the projector delivers a consistent look on screen no matter which media block is used. This is not so when text is rendered by the media block – a fact that may lead to Fox’s “Killer Reel” being added to the DCI Compliance Test Plan.
This was the first Plugfest where SMPTE 429-2 Annex A audio channel configuration performance was examined. With Interop audio, audio recorded on channel 7 of the track file comes out of output 7 on the server. Unlike Interop audio, SMPTE 429-2 labels the audio format intended, and the audio channel-pairs are contiguously packed in the track file in an efficient manner. However, for this to work correctly, the server must recognize the packing format and route the audio channels such that they are routed to the correct outputs. In this way, HI and VI-N, for example, can be placed after the last pair of audio in the track file, but always be routed to outputs 15 and 16. The good news is that, in spite of this added task for the server, all servers examined were able to respond and route audio appropriately.
If audio is responding correctly and open subtitles/captions are as good in performance as Interop, then it appears to be a fair statement that the server software demonstrated is good enough to allow the distribution of SMPTE DCP content. There are more steps to take, however, before SMPTE DCPs can move out the door of fulfillment entities. Servers in the field must be updated with the latest software, and theatre management systems must be tested for proper handling of SMPTE DCP content. Fox appears ready to take the lead in this, and will be coordinating with exhibitors to determine readiness for SMPTE DCP release. While this is a major milestone for ISDCF, the group was strongly encouraged to continue with its Plugfest demonstrations as manufacturers strive to improve performance.
Given the opportunity to have a Technicolor screening room at the group’s disposal for the Plugfest, word was put out that ISDCF would stage a high frame rate 3-D demonstration, if content were available, and if equipment were available and set up for demonstration. The door was open for a manufacturer to come in and orchestrate a demonstration. Taking the bait, DVS brought in two servers with stereo high frame rate content, shot from one helicopter of a second helicopter flying over downtown Los Angeles. But with so many standards to choose from, the DVS HD-SDI output did not use the same pinnout as the projector. A cable was found that would allow the small audience to see only one eye of the stereo content (i.e., not 3-D). The image on-screen was split, with one half of the image at 48fps, and the other half of the image at a roughly decimated 24 fps.
The result was interesting, but not spectacular. At high frame rate, the helicopter blades were a blur due to the improved motion capture. At 24fps, there was a recognizable pattern in the rotation. The test footage only had a few pans in it, during which the higher frame rate image clearly produced the sharper image. It was a worthy demonstration to bring home that, as with 3-D, high frame rate projection is not for every movie. It will add effect when lots of motion is present. But if the shots are largely closeup or scenic in nature, audiences are not going to spend money for a special presentation.
The next ISDCF meeting will be held November 2.