Triveni Digital Finds Majority of Nation's DTV Stations Have Transport Stream Errors
Problems Include Tuner Lock-up, Poor Audio & Video Quality, Lip-Sync and EPG Errors
Princeton, NJ, July 25, 2001
Triveni Digital, the leading solutions provider of high performance and real-time digital television (DTV) datacasting solutions today announced the findings of their analysis of 23 transport streams supplied by 21 U.S. digital television stations. The streams, representing 11.4% of the nation's digital broadcasters at the time, show a variety of errors which could have a negative impact on the ability of a viewer to tune in to, and enjoy, the quality of television promised by digital technology.
Problems identified included:
70%: PSIP/PSI table transmission interval, leading to receivers possibly taking longer to tune and lock up.
48%: Audio buffer usage, leading to degraded sound quality or lip sync problems.
39%: Missing PSIP tables or syntax errors, leading to receivers possibly not be able to navigate or access EPG (Electronic Program Guides).
35%: No EITs/Blank EITs, leading to blank lines in EPG for that channel.
17%: PCR jitters and frequency deviation, leading to receivers possibly not being able to synchronize with encoders.
13%: No PSIP metadata, leading to receivers possibly not being able to navigate, access EPG, and update their clock.
9%: Video buffer usage, leading to degraded video quality or lip sync problems.
"These results were disappointing," said Mark Simpson, President and CEO of Triveni Digital. "While the FCC does not mandate transport stream compliance, the specification is part of the ATSC's DTV specifications and errors can have a detrimental effect on viewers being able to watch a DTV program. Based on our findings, we have decided to extend the StreamDoctor service on a commercial basis to TV stations and system integrators." Those interested in the StreamDoctor service can email StreamDoctor@TriveniDigital.com for more information.
StreamDoctor Methodology Used
Under the StreamDoctor service, Triveni Digital analyzed DTV transport streams for compliance with ATSC standards and provided a confidential analysis report to DTV stations or system integrators who provided their DTV streams to Triveni Digital for analysis.
The streams were recorded either by the technical staff of DTV stations, by system integrators, or by the staff of Triveni Digital when requested to do so by the stations. When stations recorded their own transport streams using a recording instrument, such as Triveni Digital's StreamScope, the streams were recorded on media (such as CD, Zip disk, or Orb disk) and sent to Triveni Digital for analysis. When the streams were recorded by Triveni Digital's employees, they used Triveni Digital's StreamScope MT-20 monitor/analyzer instrument to do so. In either case, the typical time duration for recorded streams was between 60 to 65 seconds of transport stream (approximately 150MB).
Triveni Digital experts analyzed transport streams using its StreamScope MT-20 stream monitor/analyzer. The StreamDoctor analysis focused primarily on the following areas:
- ATSC Program and System Information Protocol (PSIP) standard (A/65): PSIP problems can interfere with DTV receivers tuning to channels or displaying them in electronic program guides.
- Audio and video buffer usage: Buffer underflow or overflow can cause audio or video to break up or be presented with incorrect synchronization.
- Program Clock Reference (PCR) frequency and jitter: PCR problems can cause synchronization problems with video and audio. In extreme cases they may even result in glitches in the audio or video due to lost data.
Results as of May 21, 2001 from 21 DTV stations out of 185 on air as of April 2001 representing 11.4% of DTV broadcasters at that time.
About Triveni Digital:
Triveni Digital, Inc., a subsidiary of LG Electronics, develops digital television systems, focusing on equipment for management of enhanced data and metadata in digital broadcast streams. Triveni's products for ATSC PSIP, data broadcasting, stream analysis and monitoring are renowned for their ease of use and innovative features. Triveni's Custom Solutions business enables the rapid deployment of solutions for data broadcast application. Working with leading industry partners, Triveni Digital employs an open and standards-compliant approach to the digital television market. For more Information, please contact us.
