Many stations have found that optimizing graphics for HD/SD simulcasting can be pretty challenging. For instance, a facility that downconverts HD content to create an SD channel will face many compromises with graphics presentation. Other stations with dedicated graphics devices for HD and SD channels have experienced different problems related to more complex system integration and automation during installation. Using separate HD and SD graphics processors for branding can also contribute to more complex graphics workflows on a day-to-day basis. Before we look at possible solutions, let's discuss these issues in more detail.
Simple downconversion
A typical HD/SD simulcasting system, based on downconversion of an HD feed, will involve adding channel branding graphics ahead of the conversion process. This means that the positioning of the 16:9 HD graphics must accommodate the 4:3 SD format. This often results in an awkward appearance for the HD output.
The HD graphics are simplified to work effectively in SD, and this prevents the broadcaster from using the full breadth of graphics effects possible with HD. This is a real pity, as HD opens up new branding opportunities, both in terms of the sophistication of the graphics and the use of text on the bigger, higher resolution screen area.
With downconversion, it's common to find fairly simple HD graphics positioned toward the middle of the screen, rather than in the classic position toward the edges. (See Figure 1.) Also, crawls will often have rather ungainly bookends, which reduce the amount of visible text. (See Figure 2.) Another issue inherent with downconversion is a lack of differentiation of the HD and SD channels, as they are based on the same branding graphics.
Separate graphics devices
The use of separate branding graphics devices for HD/SD simulcasting is a partial solution to this. It overcomes the need to compromise graphics positioning, and it also allows the use of more elaborate and text rich graphics on the HD channel, making the most of the format's potential. However, using separate graphics devices for HD and SD tends to create a more complex installation, typically demanding two automation interfaces and two playlists to drive the playout. This is more costly with respect to capital expenditure and more demanding for engineering to install and manage on an ongoing basis.
Importantly, separate branding devices for HD and SD also significantly increase the graphics requirements, as there is often a need for dual systems for graphics preparation, data interfacing and media management. Naturally, this adds to the complexity of the graphics workflow, and increases costs for training and maintenance.
Single processor, dual graphics engines
What is needed is a single processor with dual graphics engines for HD and SD. (See Figure 3.) This type of processor features two independent graphics engines for HD and SD outputs.
When using an HD feed, simulcasting may be performed effectively by branding the HD channel using a dedicated HD graphics engine. The SD output is derived from a downconverted clean feed, with channel branding inserted by a separate SD graphics engine.
This device can also perform simulcasting with an SD feed, with the SD channel upconverted to 1080i or 720p to create the HD output. In both cases, the HD and the SD channels will have graphics optimized for the format in terms of positioning and style.
A single HD/SD processor simplifies system integration, automation and maintenance. Just one automation interface and one playlist can drive both HD and SD simulcasting channels, and this can significantly reduce system complexity.
Perhaps even more important, the development of dual-format, template-based graphics workflow software has simplified graphics workflows in simulcasting and multichannel HD/SD environments. A multiformat graphics automation application makes it faster for designers to create graphics templates for HD and SD, and it simplifies interfacing for data-driven graphics.
With this type of environment, television-ready graphics can be created easily from a user's desktop, dropped into predefined templates, linked to live data sources and quickly inserted into playlists. Live data can be accessed once, mapped to the appropriate HD and SD templates and then sent to the delivery channels, without burdening the production process.
This advanced operation increases productivity, allowing the output of detailed and complex graphics without all the complexity of resizing and reformatting in both HD and SD. Media management is also simplified by using a single archiving and distribution system for both formats. These multiformat graphics workflow tools can also radically simplify rebranding activities for mobile TV and other new media formats.
HD/SD graphics workflows can be simplified further if the graphics system can go beyond channel branding and promotional graphics to support production graphics for news, live sports and elections. There are natural efficiencies from using a common system for newsroom graphics and channel branding when it comes to asset management, graphics creation, content editing and real-time data management, as well as work-order management and playout control. Again, obvious benefits include fewer applications to learn and support, as well as less duplication of effort, which further enhances productivity.
Under control
Other important issues in creating an effective HD/SD graphics workflow in multichannel facilities are scalability and control. Effective scalability demands an open, modular architecture that can operate well with a single user or with hundreds of users across multiple locations.
For driving multiple HD and SD channels with complex graphics, there is typically a requirement for fully automated operation and highly versatile manual control. Rapid and intuitive manual control of multilevel graphics across multiple channels demands a combined hard/soft panel or a pure soft panel solution.
Soft panels are rapidly gaining popularity because they offer effective and independent control of all the various on-screen elements. They can be readily configured to suit an operator's particular style, or accommodate changes in the channel or programming lineup. They can also offer effective previewing of graphical elements, such as idents, clips, data streams and transitions.
By considering all of these factors before selecting an HD/SD graphics system, television engineers or operators can ensure that they optimize the efficiency of the hardware and software installation, while also saving time and money, and offering the highest level of on-air presentation.
Eugene Plawutsky is product manager — graphics products for Miranda Technologies.
