EE Times article on CUBE's new third generation codec chip............
eet.com
Codec makes digital video and MPEG interoperable
By Junko Yoshida
AMSTERDAM, Netherlands - C-Cube Microsystems has unveiled a
single-chip codec that allows editing and transcoding between DV and
MPEG video streams. The device, which was shown at the International
Broadcasting Conference here, lets users of video editing machines or
broadcast video servers transcode and edit digital video streams
compressed in different formats entirely within the digital domain, on the
same chip.
"Our chip offers a truly seamless end-to-end digital solution, allowing users
to use a different compression format where it is appropriate," said Joe
Sutherland, product marketing manager of C-Cube's PC/Codec division.
Dubbed DVxpress-MX, the chip could solve a critical problem for the
broadcast and post-production community in the digital TV era: how to
make possible functional interoperability and exchange of video materials
that were produced by using incompatible compression algorithms. For
example, while a great deal of digital video footage today is captured by DV
format-based digital cameras, it often has to be edited into other footage
that is already compressed in the MPEG format for digital broadcasting.
To date, the only available solution for such a problem is a number of
decoding and re-encoding steps within the long chain of production, post
production and distribution, leading to complaints that it leads mainly to the
accumulation of compression algorithm artifacts. For example, the joint task
force of the Society of Motion Picture and Television Engineers (SMPTE)
and European Broadcasting Union (EBU) has been demanding the
development of a common ("agile") decoder in order to support the use of
more than one compression family. DVxpress-MX meets that need, said
Patrick Henry, senior director of marketing at C-Cube's PC/ codec
division.
DVxpress-MX is C-Cube's third-generation codec. It is spun out of
C-Cube's programmable video processor architecture, called DVx micro,
which is based on a Sparc RISC core, said Henry.
The new codec exploits the DVx ability to decode up to two streams
simultaneously. What's new with DVxpress-MX is that "one can do all the
real-time decoding, adding special effects such as fades, wipes and
dissolves, and cutting and splicing of two streams, even though those
streams are based on different digital compression formats," said Henry.
C-Cube engineers made some logic modifications to DVxpress, enabling it
to offer DV encoding and decoding as well as transcoding between DV and
MPEG-2 video.
Further, DVxpress-MX is manufactured in a 0.25-micron process vs. the
0.35 micron of C-Cube's earlier DVxpert and DVxpress solutions. The
result is a smaller package and a reduction in power consumption from 4.5
W to 2 W, said Henry.
More specifically, it supports frame-accurate MPEG-2 Main Level @ Main
Profile (4:2:0) running at a variable bit rate between 2 and 15 Mbits/second;
MPEG-2 Main Level @ 4:2:2 profile at a variable bit rate between 2 and
50 Mbits/s; all Panasonic DVCPro formats including DV50 running at a
constant bit rate of 50 Mbits/s; DV25 at 25 Mbits/s; multiple-stream
decoding of MPEG and DV; and real-time special effects for transitions.
Transcoding between MPEG and DV25 is done in real-time, while
transcoding between MPEG and DV50 can be carried out only at 1.5 times
real-time.
DVxpress-MX does not require a cumbersome process such as blindly
decoding a DV stream all the way, converting it back to baseband video
and then encoding it into an MPEG stream. Instead, the new codec does
intensive preprocessing under which "it intelligently reads a glot into" key
technical parameters - including quantization levels and the utilization of
allocated bits - used in the previously encoded frames and utilizes them for
the subsequent encoding, explained Sutherland.
Henry said that companies such as Panasonic, Avid and Adobe endorse
DVxpress-MX and are planning systems based on the chip. Besides the
editing station market, the codec is expected to play a key role in play-out
video servers, as well as the digital video recorder market. For example, a
video broadcast server may be storing TV commercials compressed in
MPEG-2 format, but they may have to be inserted on-the-fly into
DV-based live news for broadcast.
"That's when it becomes necessary for a play-out server to be able to
handle both compression formats," said Sutherland.
C-Cube also is getting attention from designers of video-editing machines
based on the DV format only. "A lot of our customers want to know our
chip's DV capability first, and they like its ability to decode two video
streams simultaneously," said Sutherland. The only single-chip DV codec on
the market today is the one designed by Divio Inc. (Sunnyvale, Calif.),
formerly known as Next Wave Technology. The Divio chip, however, does
not handle simultaneous decoding of two video streams.
The C-Cube codec, being sampled now, will come in two versions:
DVxpress-MX25 and DVxpress-MX50. The MX25, handling MPEG-2
4:2:2, 4:0:0 and DV-25, will be available at $175 in units of 20,000, while
the MX50 for MPEG-2 4:2:2, 4:0:0, DV-25 and DV-50 will cost $400 in
10,000 units. Volume production shipments are scheduled for December. |
