How to Get the Most From Your Graphics System

In Uncategorized by tfwm

In recent years, there has been an explosion of broadcast-quality graphics used during sermons by church ministries and for religious broadcasts on dedicated networks across the US.

Like standard broadcasters, religious broadcasters want to produce the highest quality graphics for both channel branding and program information purposes. Many churches across the country are also investing in advanced production equipment in order to provide professional presentations to parishioners. There are a number of reasons for churches to purchase a graphics system, such as the desire to include graphic elements to hymns prior to projection; to display Bible verses; the capability to add graphics to recorded services for on-air transmission; and the repurposing of material for DVD sales.

Many churches in the US have vast broadcast experience and it is now becoming commonplace to see high-end acquisition and production equipment. In fact, the religious community is recognized as one of the newest industry players, with broadcast trade shows such as NAB adding dedicated conferences to their programs.

There are many advantages of having a good on-air graphics system for churches, such as speed and ease of operation and the ability to read different industry graphics formats from other platforms – TGA, TIFF, JPEG and TGA with Alpha channels. Another major plus, particularly when animating or adding graphics to Bible Verses, is the ability to import files from applications such as Adobe PhotoShop®.

Other important features include ease of file transfer from one system to another, ease of connecting to and working with automation systems, seamlessly handling single-byte and double-byte typefaces, and the ability to drive the entire on-air graphics system without using a pointer device.

When a church ministry is shopping around for a supplier of an on-air graphics system, integration with current and future on-air graphics requirements is a must. This, together with the ability to expand storage, the price of storage expansion and ease of media management and backup management satisfies the majority of requirements.

With broadcast-quality graphics becoming a normal part of church services, it is no surprise that many ministries are looking to HD as the next step. The gap in cost and complexity between HD and SD graphics has been narrowed to the point that it is not difficult for the same system to produce both HD and SD graphics for a small premium. That has been true for a while with routers, distribution and cameras, and now applies to graphics as well.

The key to this performance jump has been the transition, industry-wide, to software-based character generators and graphics running on high-performance open platforms. The benefits of an open platform are clear. First, there is no longer the need for expensive custom hardware that was typical of the last generation of graphics products. This speeds the time to market and lowers the cost to the end-user.

The other major benefit is that the open platforms are growing in performance at a tremendous rate. The next generation of GPU, CPU, storage technology or data bus will result in improvements in system performance at a rate much faster than the broadcast industry has experienced in the past.

Remote production trucks are being built with HD-ready infrastructure, and in many cases, that now includes the graphics equipment. Much of the graphics produced today for HD sports production, for example, is still upconverted from SD, because older-generation HD graphics equipment had severe performance limitations in terms of animation and speed compared to SD. Most broadcasters agree that degrading the resolution by upconverting was less objectionable than degrading the look of the graphics by attempting to render in HD. With today’s new generation of equipment, that is no longer a problem.

Some religious broadcasters may use a character generator plug-in to carry out offline work, using a non-linear editor; character and graphics generation is performed by the software plug-in. Many of the NLEs in the market use open PC platforms, so they too have made a fast transition to HD, and there are many powerful and inexpensive systems available. It is important that the plug-in be resolution-independent so that it can operate over a wide range of HD and SD resolutions, and that it can work with many open image file formats.

With an increasing number of religious channels broadcasting on cable and satellite platforms, channel branding has become an integral component of religious broadcasting. It has evolved from a simple stationary logo in the lower right corner of the screen, to sophisticated animations, sometimes with sound, running under complex automation control. Many religious programmers want the same capabilities. Quality and high resolution is important, so upconversion is usually not an option. One advantage here, though, is that branding bugs are usually small, much less than full screen. This simplifies the design and lowers the networking storage requirements considerably.

Religious broadcasters need to keep in mind that HD files are large, particularly video clips, which are often used as animated backgrounds. Full-resolution, uncompressed RGBA is 250Mbit/s or 0.9 Tbytes/h. This amount of storage is not trivial, even with today’s large drive capacity. In rough figures, it takes three times real time to transfer a clip over Gigabit Ethernet, and users are finding it faster to “sneaker-net” a Firewire drive from one machine to the other, rather than transferring the files via network.

Most programmers will find themselves broadcasting in HD and SD simultaneously, which means that they have to create graphics content for both standards; and as much as possible, they would like not to have to create every graphic twice. The biggest problem here is not the resolution, since most graphics applications are resolution-independent and can scale an image up or down easily. The big problem, regardless of whether upconverting or working in native HD, is the difference in aspect ratio.

The most popular solution to this problem is to create all the graphics templates in 16:9 with a 4:3 protect. All important information, images and text are kept in a 4:3 area in the center. Backgrounds, lower-third banners and other similar graphic elements can be extended to the end of the 16:9 area. When displaying in 4:3, the graphics system is programmed to crop the unused side panel area. This matches the technique most commonly used for camera shots that need to be used in both standards.

High-quality upconversion is available, at a cost often comparable to the graphics system itself. Meanwhile, many products are starting to build in upconversion or downconversion at a relatively low cost.

Keep in mind that generating animated computer graphics is a good stress test for an upconverter. If your upconverter allows for adjustments, be sure to take the time to optimize it for your graphics, as the settings are often significantly different from a general-purpose scene.

Look for spatial and temporal filter artifacts: Up- and down-conversion require digital filtering in order to interpolate the missing data. Spatial filtering causes ringing that is most noticeable around character edges and uniformity of color problems, which you may see on the character face. Temporal filtering, or motion compensation, can sometimes cause severe artifacts on rolls and crawls, visible as filtering or hanging dots.