[opendtv] VC-1 standard finally arrives

  • From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>
  • Date: Mon, 10 Apr 2006 11:04:18 -0400

VC-1 standard finally arrives

Junko Yoshida
(04/07/2006 9:54 AM EDT)
URL: http://www.eetimes.com/showArticle.jhtml?articleID=3D184429614

SAN JOSE - After two years of suspense worthy of a Hitchcock movie, the
Society of Motion Picture and Television Engineers (SMPTE) has released
complete specifications for the VC-1 video compression standard.

The completion of the VC-1 standard arrived two years after originally
promised by Microsoft Corp., which has been eager to turn its
proprietary Windows Media Video 9 into an industry standard.

VC-1 documents including "VC-1 Compress Video Bitstream Format and
Decoding Process"- the standard itself- and two supporting recommended
practices can be purchased on the SMPTE website.

Asked about their own VC-1 implementations, several speakers at the
Embedded Systems Conference here this week said they are for now
depending on Windows Media Video 9 (WMV9), Microsoft's implementation of
VC-1, to bring it to the market.

Ajit Rao, group manager for multimedia codecs at Texas Instruments, said
that WMV9 is "identical" with VC-1. But he added that the two "may drift
in the future."

While Microsoft is making sure that WMV9 decodes VC-1 syntax correctly,
the software giant may add new tools and improve future versions of WMV,
Rao explained.

Interoperability of VC-1, however, is a concern for both encoder and
decoder vendors.

According to SMPTE, its Compression Technology Committee has formed a
new Working Group dedicated to providing maintenance of the test
materials and documents, as well as the administration of a bitstream
exchange program.

In theory, if everyone in the industry used Microsoft's implementation
of VC-1, interoperability between different encoders and decoders could
be insured. But, in reality, every encoder vendor, reading SMPTE
documents, can approach VC-1 encoding problems with a different

In other words, even if "the syntax one encoder emits must adhere to the
standard, the code values stuffed into different elements of the syntax
can be radically different," according to an industry expert who spoke
on the condition of anonymity. The industry cannot be sure of
interoperability unless it carries out "an industry-wide bitstream
exchange program between different encoder manufacturers and different
decoder manufacturers," he added.

Indeed, TI's Rao, while outlining a number of compression tools
available for different video codecs at the conference here, stressed
that although compression standards specify the required syntax, "it's
your choice" to make algorithmic decisions for codec implementation.

Nonetheless, VC-1-- with or without industry-wide interoperability
testing-- is positioning itself for deeper inroads in the consumer
electronics market.

HD DVD and Blu-ray, the next-generation optical media specifications,
have chosen VC-1 as one of three formats studios can use to deliver
their movies in high definition. Warner Bros. Studios announced they
will use VC-1 when they release titles in HD DVD.

Modeo, a mobile TV company based in Houston, will broadcast mobile TV to
cell phones, portable media players and laptop computers by using
Microsoft's WMV9.

The consumer electronics industry today is being bombarded with new
video compression technologies-- namely H.264, VC-1 and China's AVS1.0.

TI's Rao, in comparing VC-1 and AVS1.0 with H.264, said that "VC-1
achieves a compression ratio similar to H.264 but at lower complexity."
In contrast, China's AVS1.0, while similarly reducing the complexity
compared to H.264, "loses a little in compression efficiency," he added.

Rao said that when compared to the H.264 Main Profile, China's AVS1.0 is
"about 0.3 dB worse in average for progressive sequences" and "up to 1.2
dB worse for interlaced sequences." China, however, is currently
defining a new profile in AVS1.0 to resolve such quality issues, he

All material on this site Copyright 2006 CMP Media LLC. All rights
You can UNSUBSCRIBE from the OpenDTV list in two ways:

- Using the UNSUBSCRIBE command in your user configuration settings at 

- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word 
unsubscribe in the subject line.

Other related posts: