GRASS VALLEY PROFILE XP PVS Series, System Manual

Page: 27 / 352

Video compression for standard definition
23 July 2004 Profile XP System Guide
27
Video compression for standard definition
The Profile XP Media Platform uses a variety of standard definition video compression
formats: MPEG-2, DVCPRO 25, DVCPRO 50, and MPEG D10. Files of different
compression types can be stored concurrently on the media platform, and accessed
concurrently by different channels.
MPEG-2 support
The PVS1000 uses MPEG-2 4:2:2 @ Main Level encoding with selectable bit rates from
4 Mb/s to 50 Mb/s. The additional chroma resolution that 4:2:2 sampling gives provides
good multi-generation capability as well as up-conversion quality. 4:2:0 chroma
sampling is also available, allowing the creation of clips that can be up converted to HD
resolutions on an HD decoder with the Definition Independent option, which is included
on the PVS3500.
Seamless play and cuts editing at any bit rate and any GoP is made possible by the
Profile XP dual MPEG decoder architecture that allows storage efficiencies of a long
GoP and maintains the ability to cut on any frame and play clips back-to-back
seamlessly. This provides all of the advantages of long GoP encoding, without the
limitations.
The PVS1100 provides MPEG-2 4:2:2 support at bit rates up to 25 Mb/s, and up to
50 Mb/s with the 50 Mb/s option. The PVS1100 also provides MPEG D10 compatibility.
MPEG D10 is an MPEG format that was developed for tape. It is characterized by a
selectable fixed bit rate (30, 40, or 50 Mb/s) and constrained byte GoP (CBG), that
prevents the size of a field from exceeding the physical size of the tape scan.
DVCPRO support
The PVS1100 provides DVCPRO 25 and optional DVCPRO 50 compression formats.
These formats improve work flow by allowing the transfer of material between other
equipment and the Profile XP media platform without re-encoding the compressed
video.
Video compression for high definition
The PVS2000 uses MPEG-2 4:2:0 @ Main Level encoding with selectable bit rates from
20 Mb/s to 80 Mb/s.
Serial Data Transport Interface (SDTI)
SDTI is available as an option to the PVS1100 Series. The SDTI board provides two
channels, each of which you can configure to be an input or output. The SDTI board
accepts input of DVCPRO 25 video at 1x, 2x, and 4x real time, and input of DVCPRO
50 video at 1x and 2x real time. SDTI output of DVCPRO 25 is selectable at 1x or 4x;
output of DVCPRO 50 at 1x. This version of system software supports DVCPRO 25 and
DVCPRO 50 as SDTI video formats.