Any broadcast, satellite and cable engineer responsible for building or maintaining DTV facilities has probably come up against an intermittent problem or a problem with one particular brand of DTV or set-top box and been frustrated by how hard it is to find the root cause of the problem.
The problem could be in the compressed video stream, or it might be in the transport stream or PSIP information used to carry the compressed video stream. It could be a problem with the DV transmitter or modulator. Tektronix says its expanded line of MPEG analyzers can help.
“The first step for an engineer troubleshooting a problem in a digital broadcast system is always to narrow a fault down to the source,” said Paul Robinson, senior manager of the MPEG test segment of Tektronix' video product line. “Detailed analysis at the appropriate layer can only be performed once the source of the problem is identified. The new portable MTS400P and mid-range MTS415 video analyzers extend the industry-leading Tektronix portfolio of complementary MPEG analyzers, generators and monitors."
The MTS415 provides several RF interfaces, including 8VSB, 8PSK, DVB-T and QAM. Except for the MTS430, which is designed for R&D labs, the other units do not include RF interfaces. Both units provide real-time transport stream analysis. The MTS415 includes a buffer analyzer, transport stream compliance analyzer, and a PES analyzer. These are also available on some versions of the MTS400P. MPEG-2 and MPEG-4 encoders are found in editing equipment, video servers, digital ENG and SNG trucks and, of course, the ATSC DTV transmission stream.
Determining whether these encoders are putting out a compliant data stream can be difficult as not all decoders will react to non-compliant streams the same way. The Tektronix MTS4CC compliance checker should help.