A common theme of NAB conference speakers this year described how IT in broadcasting is taken for granted. Computer systems, software, networks and storage now dominate the broadcast and production infrastructure. So naturally, having skipped NAB last year, I was anxious to see how much further test and measurement equipment has moved into the IT domain.
Testing for perfection
End-to-end testing of DTV systems requires a carefully designed digital stimulus signal source. Sarnoff Compliance Bitstreams for H.264/AVC enable real-time and automated compliance testing of digital video decoders, DTV receivers and cable converters. The suite includes versions of the company's syntax, stress and error resilience bit streams tweaked for testing OpenCable picture formats, format transitions, channel change and audio. The H.264 bit streams join a line of Sarnoff compliance testing products for H.264, MPEG-1, MPEG-2, ATSC, closed captioning, PSIP program guides, digital V-chip, lip sync and picture quality.
QoS and QoE
In an effort to squeeze every possible source of revenue into their 8-VSB/MPEG-2 transport stream, many broadcasters have sacrificed the data rate of their HD service in order to transmit multicast SD. Sometimes it's to the point where macroblocking abounds during scene transitions. Consequently, many vendors introduced quality analysis equipment based on human visual system modeling for deployment at the reception end of the broadcast chain.
Pixelmetrix debuted the Electronic Couch Potato (ECP). Designed to analyze content downstream after the STB, ECP enables broadcasters to ensure that their feeds are getting to the consumer in pristine condition. Decoded video and audio is monitored for quality of experience, channel switch time, freeze frame, blackout and audio loss.
OPTICOM showed PEVQ, which offers a perceptual evaluation of video quality by producing mean objective scores typically used in subjective testing of video and audio quality. Key performance indicators include PSNR, blockiness, frame skips and freezes, as well as temporal activity and spatial complexity measurements.
The Tektronix PQA500 features critical and casual modes that predict perceived (subjective) video quality. Objective measurements include PSNR and artifact classification.
Turn it up, turn it down …
Variations in DTV sound levels have intensified efforts to monitor and adjust audio metadata in order to deliver audio to the consumer at a perceptually constant volume. Evertz's IntelliGain is a program loudness control system that works like an analog AGC circuit and digitally adjusts audio levels for loud commercials while preserving program dynamic range. The technology can be installed in the company's frame synchronizers and audio embedders/de-embedders, and is VistaLINK controlled and monitored.
Taking the ATSC A/52 route, the Linear Acoustic LAMBDA digital audio and metadata monitor accepts audio metadata via a serial input or extracts it from the VANC of an HD-SDI input. Audio and metadata are simultaneously displayed, and any channel, channel pair or downmix can be monitored. Ethernet connectivity provides access to all metering information.
The Miranda DAP-1781 performs loudness control and measurement, using ITU-R BS.1770 or Leq(A). The loudness value can trigger an alarm if there are discrepancies with the associated metadata and insert corrected dialnorm metadata into a program stream. It also modifies the audio levels of the program to match a target dialnorm value.
Big is better, small is best
Self-contained, handheld portable test systems that included test-signal generation and monitoring as well as a smaller form factor version of journeyman analyzers were new this year.
The Harris HD-STAR monitors and generates SDI streams with embedded audio. Also new, the ASI-STAR monitors transport stream PSIP table information and ETR 290 priority 1 alarms, while being able to record and playout ASI transport streams.
Hamlet launched a new plug-in for its FlexiScope handheld devices. The module generates SD/HD-SDI test signals with alphanumeric identifiers and embedded audio. The plug-in can be installed on the MicroFlex, MonitorScope and DigiScope 9000 products.
Targeting ENG vans and field applications, Tektronix introduced the portable WFM5000 waveform monitor. This short-depth unit auto-senses SD or HD video input formats, supports 16 channels of embedded audio and can log 10,000 errors. Waveform, picture, gamut, audio bars and lissajous figures can be displayed. AC and DC power options are available.
With the end of NTSC broadcasts less than a year away, it is important to know if your DTV transmission footprint covers your analog DMA. To fill this need, portable network-enabled DTV RF monitoring equipment is available.
The Agilent N9340B is a 3GHz RF spectrum analyzer designed for field use and features LAN and USB connectivity for remote control and data transfer. The handheld device measures signal stability, out-of-channel emission and optionally AM/FM, ASK/FSK modulation analysis. PC control and monitoring software is included.
IneoQuest showcased its Singulus Lite 8-VSB Cricket broadcast signal confidence monitor. The 8-VSB signals are decoded. Then RF and the MPEG transport stream are analyzed while video and audio QoS are verified. Unattended 24/7 monitoring of RF coverage and STLs is possible over a network connection and can be integrated with the iVMS video monitoring system.
Pixelmetrix shrunk two of its offerings. The DVStation-MINI TSP and the DVStation-MINI PSK monitor and analyze transport streams and RF signal quality, respectively.
Although broadcasters, systems integrators and vendors are learning to leverage IT in broadcast, anyone familiar with an IT NOC knows that the media industry still has a long way to go to get up-to-date with IT technology.
As more content movement standards such as BXF and Archive eXchange Format (AXF) find their way into operations centers, it will become increasingly important to monitor more than TS and QoS. Perhaps SMPTE should resurrect its effort to standardize SNMP management information bases (MIBs).
I would like to see a turnkey converged test, measurement, monitoring and analysis solution that can monitor traditional broadcast equipment as well as networks, storage, computer resources, application health and security. Maybe if I asked Zoltar as I passed him on Las Vegas Boulevard, my wish would be granted.
Phil Cianci is a design engineer with Communications Engineering, Inc.
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