Harmonic Bows Next-Generation Encoder

In advance of The Cable Show in Washington, D.C. next month, compression supplier Harmonic has introduced its latest hardware encoding product, the DiviCom Electra 8000, which can compress standard-definition and high-definition video using both the MPEG-2 and MPEG-4 encoding schemes and also upconvert SD signals to HD for cable or satellite distribution. It can deliver four channels per one rack unit (RU) chassis.

The Electra 8000, which is slated to ship in June, is also designed to support 1080-line-progressive HD at 60 frames per second, a high-quality picture format that isn't yet being delivered by any programmers today but which some networks expect they will eventually be producing content in, perhaps for new pay-per-view channels.

The new Harmonic product is also aimed at local over-the-air broadcasters, as it can deliver a statistical multiplex of one HD and several SD program streams from the same piece of hardware that can be transmitted through an ATSC channel. That previously required using three separate boxes: an HD encoder, an SD and a statistical multiplexing unit.

The 8000 comes preloaded with the software to support all of its possible uses, but customers only pay for the ones they enable by turning on a software license key, so a local broadcaster who has no need for MPEG-4 AVC encoding doesn't have to pay for it.

"We were always dreaming of making a universal encoder for MPEG-2, MPEG-4, SD and HD, and now that's come true," says Elie Sader, Harmonic's product marketing manager for encoders. "That's something very exciting for us."

A key goal in designing the 8000, says Sader, was to provide "business continuity" for customers as they adapt to changing technology, such as the move from MPEG-2 to MPEG-4 AVC compression. So the device has built-in "transcoding" capability---it can receive AVC content and re-encode it in MPEG-2 for local distribution. Service providers such as telcos can also use the Electra 8000 to deploy SD MPEG-2 services today and then seamlessly transition to HD AVC. It also has a built-in broadcast quality up/down converter, which allows an operator to take a lineup of existing SD channels and upconvert them to HD.

Other additional features include the ability to deliver a second channel output for each program stream, which could range from low-resolution video for picture-in-picture applications up to full HD resolution for switched digital video (SDV) or time-shifted TV applications. For flexibility, the 8000 has IP or ASI outputs, multiple audio format options, native support for Digital Program Insertion (DPI), and Harmonic's FLEX integrated decoding with IP, 8-VSB or ASI inputs.

Of course, the major reason to buy a new encoder is to be able to deliver the same or better picture quality using fewer bits, and according to Sader, the 8000 achieve significant improvements in bit-rate efficiency over the current 7000 flagship encoder. He says the unit is able to deliver high-quality MPEG-2 HD at bit rates of 9 megabits or less using a statistical multiplex, which would allow cable MSOs to transmit up to four HD MPEG-2 services in one QAM (36 megabits per second of throughput). Meanwhile, the 8000's MPEG-4 AVC encoding can deliver constant bit-rate HD video at 5 Mbps or less, he says.

Besides building in increased versatility into the 8000, "you have to come out with new compression gains to justify having a new product," notes Sader.