Squeeze harder

More than 25 companies demonstrated products in support of H.264 at NAB. Many of these products also support the VC-1 codec from Microsoft. These products span a wide range, including: real-time hardware encoding; software encoding; hardware decoders; software decoders; dedicated chips and/or programmable processors for encoders and decoders; and transport products to deliver compressed content.

As was the case with MPEG-2 encoders, implementing new real-time hardware encoders involves a significant learning curve. H.264 and VC-1 use many new tools, and it will take some time for manufacturers to develop and optimize products for real-time encoding, especially for HD formats. Software encoders and decoders have existed for these H.264 and VC-1 for several years; however, many broadcast applications require real-time capabilities.

Most of the product announcements and technology demonstrations related to real-time encoding reflect the reality that these products are still in the early stages of development. Several companies will offer standard definition encoders in the near future, with plans to support high-definition formats in the future.

TANDBERG Television has taken an early lead with advanced encoding systems for H.264 and VC-1, claiming to have shipped more than 500 such systems. The company has developed a programmable approach for the new advanced codecs, which will allow them to be upgraded as the systems are optimized in the future. TANDBERG demonstrated two standard-definition encoders, the EN5920 for VC-1 and the EN5930 for H.264, and two new HD encoders, the EN5990 for H.264 and the EN5980 VC-1.

Modulus, which announced its formation just before NAB2004, came to NAB2005 with its new ME-6000 H.264 HD encoder, to complement the ME-1000 H.264 SD encoder announced last year. Able to support more than 600 billion operations per second, the programmable design of the ME6000 HD encoder will allow this product to evolve as the encoding tools are optimized.

The DiviCom MV 100 encoder from Harmonic is an advanced MPEG-2 standard-definition encoder with software options to support H.264 and VC-1. Harmonic also offered a technology demonstration of an H.264 HD encoder.

Envivio, an established developer of software tools for MPEG-4, is now adding real-time hardware encoding and decoding to its product line with support for H.264. The company's 4Caster and 4Coder Broadcast series MPEG-4 AVC/H.264 encoders are optimized for digital news gathering (DNG), contribution/distribution applications and digital television services delivered via cable, IPTV, satellite or terrestrial, and enterprise networks.

While MPEG-2 encoders are now becoming mature products, Snell & Wilcox has pulled a trick or two out of its vast experience with inter-format (standards) conversion, to give the MPEG-2 tools a boost in performance. The Memphis encoder takes advantage of the company's Emmy award winning Ph.C phase correlation motion estimation and Prefix compression pre-processing to bring MPEG-2 to a higher level of compression efficiency. The Memphis encoder can be configured initially for SD applications and then upgraded to HD capabilities in the future.

Squeeze better

Compression technology is now playing an important role in video acquisition. The consumer DV format and several variants, including Panasonic's DVCPRO 25 and 50 and Sony's DVCam, have been using intraframe compression for several years. In the past year various flavors of HDV have emerged using Long-GOP MPEG-2 encoding at 25Mb/s; several products were shown at NAB that will extend HDV to higher bit rates to support higher frame rates.

The Frequency Range Extensions to H.264 are likely to play a major role in acquisition products in the future. Several off-the-floor technology demonstrations at NAB provided a glimpse into a future that will take advantage of the extended encoding ranges established via the Frequency Range Extensions, which include profiles that support high-definition formats with up to 12-bit samples in 4:2:0 (progressive), 4:2:2 (interlaced) and 4:4:4 color spaces.

The story of compression at NAB2005 does not end with H.264 and VC-1. Wavelets are showing up in more applications, including the new APR/ClipStore MXc HD/SD video clip server from Accom. And Ikegami is now offering the HDN-X10 Editcam, which captures HD to hard disk packs using Avid's DNX compression technology.

Craig Birkmaier is a technology consultant at Pcube Labs, and he hosts and moderates the OpenDTV forum.