Harmonic Adds 'Full HD' Compression
Vendor to Show 1080p High-Definition Video Encoded in MPEG-4
By Todd Spangler -- Multichannel News, 8/29/2007 7:33:00 AM
Harmonic has added support to its video-encoding platform for the 1080p high-definition format -- but the feature is available only in MPEG-4 format, which most digital-cable set-tops in the field today don’t support.
The company said its DiviCom Electra 7000 platform will encode 1080p HD video at 24 frames per second, in MPEG-4 Advanced Video Coding (H.264) format, through a firmware upgrade. The 1080p spec is the so-called full HD specification, which is used by high-definition DVD formats.
In addition, next week at the IBC 2007 tradeshow in Amsterdam, Harmonic plans to demonstrate the system encoding 1080p at double that rate -- 50 and 60 frames per second. In Europe, the highest 1080p HDTV standard is 50 fps; in North America, it’s 60 fps.
HD video transmitted over cable networks today is typically in 1080i, compressed using the MPEG-2 standard.
The 1080p (“progressive”) technology delivers image quality considered superior to the 1080i (“interlaced”) format. A progressive-scan display reproduces an image one line at a time, whereas an interlaced display draws odd-numbered horizontal lines first and then even-numbered ones.
"The new support for 1080p24 on the Electra 7000 enables operators to offer premium HD picture quality to subscribers, and the demonstration of our next generation 1080p50/60 technology takes high definition even higher," Harmonic senior manager of encoder product marketing Arnaud Perrier said, in a statement.
According to Harmonic, the platform encodes 1080p24 at bit rates similar to 1080i HD in MPEG-4 (6 to 9 megabits per second, depending on the nature of the content).
Video encoded in 1080p at 50 or 60 frames per second will require roughly twice the bandwidth; Harmonic said the 1080p50/60 demo at IBC will run video at about 15 Mbps.
