Creating graphics

Mar 1, 2006 10:39 AM, Transition to Digital e-newsletter

Graphics has become a major portion of the branded identity of broadcasters. Glance at a logo and the network and broadcaster are instantly identified. Graphics production is a core process for all broadcast operations.

With the necessity to simulcast NTSC and DTV for the next few years, dual color space, pixel/raster formats and aspect ratios will require intelligent design and creation of GFX elements, infrastructure engineering and workflow processes. In addition the infrastructure must be agile enough to handle elements used for IPTV, Internet, cell phones and other emerging technology-based business models.

Designing GFX for SD and HD

The difficulties broadcasters face when creating graphics fall into two broad categories: presentation and color.

Presentation:

• Aspect ratio:16/9 HD and 4/3, SD (square pixel issue)
• Resolution: HD, SD and analog NTSC
• Display scaling (multiplatform, cell phone, IPTV)

Color:

• Color space: HD, SD and NTSC
• Color depth and range: 8-, 10-, 12-bits; ATSC 16 -235; CG 0-255 (both 8-bit)
• Color components. Y,U,V and R, G, B

By the numbers

Aspect ratio and resolution are dependent on each other (at least in the United States). HD will always be 16/9, SD 4/3. An efficient production process will create GFX once in such a way so that the elements can be used in both formats and look good. This must be true regardless of whether the GFX is overlayed on an HD source, center cut and downconverted to SD, or if it is used in an SD production and mixed in master control.

The difficulty becomes apparent when doing simple calculations for various formats on a pixel by pixel and line by line basis. Ignoring the interlaced/progressive issue, only a few pixel and line ratios are simple small numbers when comparing formats.

HD to NTSC
Vertical: 1080/480 = 2.25, 720/480 = 1.5: 9 to 8, 3 to 2
Horizontal: 1920/640 = 3, 1280 /640 = 2: 3 1920 or 2, 720 pixels are 1, 640 pixel

HD to HD
Vertical: 1080/720 = 1.5: 3, 1080 pixels are 2, 720 pixels
Horizontal: 1920/1280 = 1.5: 3 1080 pixels are 2, 720 pixels

HD to SD
Vertical: 1080/480 = 2.25, 720/480 = 1.5
Horizontal: 1920/720 = 2.666 …, 1280/720 = 1.7777, not small whole numbers

Graphics created in either format must scale easily in whole numbers between formats, or edges will get soft due to interpolation. Anti-aliasing algorithms are used to correct this (see sidebar) and are applied to both alphanumeric characters and graphics.

864 x 486 canvas mapping

A compromise approach is to use an 864/486, 16/9 canvas to create GFX elements. GFX designers can feel comfortable because what they see on the display is what the element will look like geometrically in HD.

864/486 = 1920/1080 = 1280/720 = 16/9 = 1.777… square pixels

A center cut to NTSC will not cause visual distortion of the GFX element because NTSC has square pixels.

NTSC 640/480 = 4/3 = 1.333… square pixels

This canvas size also facilitates anamorphic conversions that can be layed to tape as SD on D-1 or DigiBeta. But care must be taken to use the correct settings in the graphics application to convert to non-square pixels.

864/486 = 16/9 = 1.777… square pixels
720/480 = 3/2 = 1.5 which on a 4/3 aspect ratio (1.333…) are not square pixels

Color space conversion

Computer GFX systems represent RGB color values in various bit depths (8, 10, 12). For 8-bits, computer color space runs the range 0-255 but for ATSC DTV the range is 16-235. Subsequently, if a GFX element is composited with video content later in the production process, non-legal colors may be produced.

An informative article by Dave Guerrero of Videotek and a Tektronix Application Note discuss color space issues.

Standards for color space are abound. For ATSC HD, SMPTE 274/ITU 709 while ITU 601 /SMPTE 259 is used for SD. NTSC color space should adhere to SMPTE 170 and SMPTE 240.

SMPTE EG 36-2000 details “Transformations Between Television Component Color Signals”. Heavy on the math, a glance at the color standards listing Appendix B reveals why there is so much confusion.

Color space legalizers, such as the Leitch DL-850HD color legalizer (a Broadcast Engineering NAB Pick Hit Award recipient) can ensure that any signal leaving the MCR occupies legal color space. However, there is no guarantee that the colors are aesthetically pleasing!

Most GFX creation applications have the capability to legalize color space to broadcast standards and store elements in RGB or convert to YUV.

Multiplatform production

With the need to repurpose content for various distribution channels and consumer devices, GFX elements cannot be indiscriminately piped though conversion resources and be expected to result in an acceptable display. It is obvious that fonts and GFX designed for HD will not play well on a 2.5in LCD no matter how they are anti-aliased.

An intelligently engineering infrastructure married with an efficient multiplatform workflow is the answer. In one scenario, appropriate for DTV or NTSC broadcasts, the GFXs and video are mixed in a PCR with conversion further downstream.

To use this identical content on a cell phone, a different workflow must be used. The original video must be converted from a clean feed to the appropriate format. The GFX must also be converted clean (key and fill) to a size (and font) appropriate for a cell phone display. So now there are two parallel production processes.

The efficiency of this multipath production and conversion process is that the GFX element is created only once and then converted to the necessary formats. An asset management system can facilitate the workflow by performing transparent folder-based format conversion.

GFX automated assembly

Automated graphics assembly is an efficient way to assemble GFX just in time to take to air. For sophisticated data dependent designs, the elimination of manual intervention and integration of database access is a powerful process and speeds up the time-to-air. This is particularly useful in a live production or news show.

First GFX templates are created. For example, consider a full screen, dual headshot with online voting results and previous results displayed in the lower third. The layout with placeholders is created in a GFX application. Headshots and previous results exist in a database. Online voting is updated in real time and is periodically updated in the template. An application will direct all this information into a template and push the completed GFX to a GFX playout server and is ready to air.

Who knows what tomorrow may bring?

The challenge is to engineer an infrastructure that supports all formats, while minimizing production time by integrating efficient GFX production workflow processes. This emphasizes the need for careful planning, requirements gathering and business integration. A brute force approach may work, but it will be expensive and stressful.

Fonts and graphics must be carefully designed to minimize aliasing when scaling between formats. Should they be produced once in highest resolution and then down converted? Or is original creation best in the final delivery format, going on the assumption that no conversion is a good conversion, i. e. that any conversion will degrade image quality. What will be the impact of cascaded transformations?

In any event, professional engineering practice dictates an analysis of GFX artifacts produced by conversion as they travel through the production process and distribution chain.

Creating sophisticated GFX, effects and animations requires high-end compute power, high-speed networks and HPHA storage. In the next Transition to Digital, IT resources, computer platforms, render farms, GFX cards, networks and storage used in the creative phase of the media lifecycle will be discussed.

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G-SAM to produce NAB annual DAM pavilion

Mar 3, 2006 3:39 PM

For the third consecutive year, members of G-SAM have come together to form the program advisory council for the DAM pavilion at NAB. The group is comprised of end users, vendors, integrators and consultants and is charged with developing conference sessions that are both timely and relevant.

The result of this group’s efforts is an agenda of conference sessions that span three full days beginning on the opening day of NAB 2006. Each day has a separate theme and together these sessions form a comprehensive overview of what is important in digital asset management.

Speakers are being sought for a variety of topics, including:

• Select the right DAM vendor for your need Analyzing current workflows and defining future workflows that addresses business needs
• Differing view of Metadata and Taxonomies
• How to achieve quick ROI and low TCO
• IT and Broadcast OPS — get along and prosper
• How to build the business case and secure funding for your project
• What are web services and why should you care
• Low resolution to high definition: Analyzing the different file formats
• Broadcast vs. IT integration.

Submit proposals to Per Sjofors, G-SAM EVP, chairman of the programming committee, at per.sjofors@g-sam.org.

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IEEE International Symposium on Broadband Multimedia Systems and Broadcasting 2006

Mar 3, 2006 4:01 PM

This new IEEE industry-oriented symposium will bring together content originators and distributors, wireless service providers and technology developers and suppliers of equipment, systems, and consumer platforms focusing on research and development, applications and implementation of mobile and portable multimedia systems. Papers will address the technology in this emerging field. The symposium will run multiple session tracks. One session track will focus on industry and applications while a second track addresses research and development. The agenda includes:

• General-interest plenary sessions
• Keynote luncheon
• Applications and implementation breakout sessions on spectrum and coverage planning; field trials; system and service planning; consumer platforms; and networks
• Research and development breakout sessions on wireless networks; diversity and space-time coding; synchronization and equalization; video processing and adaptation; receiver RF design; video/audio coding and quality assessment; video compression; and digital radio, DTV, datacasting and interactive services
• Thursday evening welcome reception
• CTIA Wireless 2006 keynotes and exhibits.

For more information visit www.ieee.org/bts/multimedia.

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HDTV: Making the Transition seminar

Mar 3, 2006 4:11 PM

HDTV: Making the Transition, a traveling seminar presented by Linear Acoustic, Miranda and Omneon, focuses on the factors driving the transition to HDTV, as well as the technologies underlying this shift within the global broadcast industry.

Each seminar will address the fundamental elements of working in HD, examine the key systems building blocks for HD broadcast infrastructures and include case studies highlighting leading broadcasters' experiences in making the shift to HDTV.

During the seminar, engineers from the three companies will take an in-depth look at the drivers for HD from consumers and broadcasters; review the fundamentals of video and audio formats for HDTV; explore distribution, routing, conversion, editing, servers and master control systems; and then turn the discussion toward practical implementation of HDTV and its realities.

The first seminar was held on Feb. 28 in New York City. Other dates include: May 23 in Los Angeles, June 27 in Washington, D.C., Sept. 26 in Chicago, Oct. 24 in San Francisco, Oct 26 in Seattle and Nov. 28 in Miami.

For more information visit www.hdseminar.com.

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Snell & Wilcox introduces Quasar

Mar 3, 2006 4:22 PM

Snell & Wilcox has announced Quasar, an HDTV upconverter that integrates motion compensation technology. Quasar combines Ph.C motion estimation, HD conversion and Prefix compression pre-processing in a 1RU package.

Designed with intuitive controls, the upconverter handles video, film, graphics and mixed media sources. It upconverts interlaced SD 525 and 625 material to 720p and 1080i HDTV formats. Captions, graphics, logos and branding are also converted, while an integrated clipper and legalizer guarantees correct display.

An onboard aspect-ratio converter comes with a series of fixed presets for the most common conversions. Quasar also supports widescreen signaling to allow for easy integration into a transmission playout environment.

The upconverter provides a comprehensive range of image processing controls and a frame synchronizer. Signal conditioning and noise reduction filters enhance all incoming sources for optimum quality. Additionally, Quasar offers audio support, including embedded, AES and compressed formats, supports closed captions, and has a dual redundant power supply.

For more information visit www.snellwilcox.com.

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da Vinci’s improves digital mastering suite with SGI shared file system

Mar 3, 2006 4:29 PM

da Vinci and SGI have completed qualification testing of SGI InfiniteStorage Shared Filesystem CXFS on a SAN with da Vinci Systems' Resolve digital mastering suite. Designed to process extremely large files, such as those used in DI processes, Resolve delivers workflow flexibility and performance fully realized with a high-performance network.

The recently completed testing shows that SGI CXFS Filesystem enables Resolve to run two streams of 2K data simultaneously in real time over a SAN. SANs can be configured with CXFS to provide enough bandwidth to satisfy the needs of multiple Resolve systems as well as other editing, compositing and creative tools in a facility.

CXFS enables multiple computers running different operating systems to directly access a single shared 64-bit file system within a SAN, allowing all systems in the environment to access the same file simultaneously at local or near-local disk speeds. CXFS improves data workflow by providing the performance and scalability of a SAN with the file sharing and connectivity of network-attached storage, addressing two fundamental challenges in data management: fast access to information and integration of multiple operating systems.

Resolve is da Vinci's digital mastering suite, featuring da Vinci's image enhancement expertise and familiar interface packaged with nonlinear conforming tools. It is designed specifically for the DI postproduction environment and utilizes a nonlinear approach that allows flexibility and speed while leveraging the da Vinci's toolset.

For more information visit www.davsys.com and www.sgi.com.

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KCRA acquires Harris NUCLEUS control panel

Mar 3, 2006 4:33 PM

Hearst-Argyle Television-owned KCRA in Sacramento, CA, has purchased the first Harris NUCLEUS real-time control panel.

NUCLEUS is designed to centralize the operational control of processing, branding and routing products.

Providing user-configured control at the center of station operations, NUCLEUS offers real-time control and monitoring of any Leitch CCS Protocol-enabled device, including the X75 M-PATH multiple-path up-, down-. crossconverter and synchronizer and products within the NEO and 6800+ platforms. The product is configured with an intuitive drag-and-drop wizard.

NUCLEUS provides more knobs for parameter adjustments, more buttons to quickly invoke parameter value changes and an enhanced display to improve overall operation.

For more information visit www.harris.com.

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MTV Networks launches new HD channel in Dolby Digital

Mar 3, 2006 4:42 PM

MTV Networks Music Group has launched its first high-definition channel, MHD, with Dolby Digital 5.1 audio.

Dolby Labs said MHD would use Dolby E, a professional-quality compression technology, to deliver the multichannel audio signal to their broadcast centers. The audio is then re-encoded into Dolby Digital 5.1 for transmission to cable head-ends and satellite providers, where it is passed on to viewers with HDTV receivers or set-top boxes.

Dolby Digital delivers up to 5.1 discrete channels of surround sound. It is the audio standard for North American HDTV and digital cable systems, and is an optional audio format for most digital video broadcast applications worldwide.

Dolby E is a compression technology designed for network distribution of up to eight channels of audio, plus metadata, in the space of two traditional audio channels.

For more information, visit www.dolby.com.

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Zaxcom’s new digital wireless microphone transceiver

Mar 3, 2006 4:47 PM

Zaxcom’s wireless microphone transceiver family now includes the TRX900AA. The transceiver operates for up to 12 hours on two AA batteries and provides integrated recording of up to 12 hours of audio. Designed for use in applications that require a lavaliere microphone, the new system simplifies remote production with built-in IFB support, timecode transmission and RF remote control from up to 200ft away.

The TRX900AA records audio in the WAV format directly to a Flash memory card for transfer to PC or Mac. Optional timecode transmission and video sync generation will allows the user to transmit two channels of audio, timecode and video sync to one receiver on the camera. Video sync types include tri-level, NTSC, and PAL. The TRX900AA features a built-in IFB receiver that allows the user to receive cues and other information from the production staff without an additional body pack.

To learn more, visit

For more information visit www.theultimatewireless.com.

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FOR-A to show MC-10AD HD/SD A-to-D converter at NAB2006

Mar 3, 2006 5:02 PM

At NAB2006, FOR-A will feature the MC-10AD HD/SD A-to-D converter, which can be used to convert HD or SD analog component signals into SDI signals.

The MC-10AD HD/SD analog-to-digital converter converts HD or SD format analog component signals into HD-SDI or SD-SDI signals. The MC-10AD supports 1080/59.9 4i, 1080/50i, 1080/60i, 720/59.94p, 720/50p, 720/60p and NTSC/PAL, and can be used by all HDV users for live production, newsgathering and production recording.

Features include analog-to-digital conversion mode and genlock mode. The white and black levels of the RGB or YPbPr input signals can also be adjusted. The unit currently is available.

For more information visit www.for-a.com.

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