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JVC Professional APRIL 2007 NAB-2007 The ProHD Report
Copyright 2007 JVC Professional Products Company All rights reserved
Page 25 of 43
File-based work flow inside the News Automation Server System. Once your
20Mbps ProHD news clips are delivered to the TV station and ingested into the news
servers and NLE workstations, the ProHD ENG system has done its job. The M2T
clips (ProHD MPEG-2 at 20Mbps) can be utilized for highly attractive low bitrate
file-based work flow, but it may make sense to decode ProHD to HD-SDI and then
re-encode upon ingest to the native HD compressed intra-frame format of the news
edit and server system, as this will support your existing work flow and accomplish
nearly 0 latency on play-out to air. If you are currently operating NLEs and/or
servers with the DVCPRO-HD format, then re-encoding to intra-frame DVCPRO-
HD 720p60 when ingesting is a viable option, but bear in mind that the legacy
DVCPRO-HD codec will limit horizontal resolution to 960 pixels luminance and 480
pixels chrominance (from ProHD’s 1280 and 640 respectively). Also, the gross real-
time bitrate for DVCPRO-HD is about 120Mbps including overheads.
To assure full ProHD bandwidth, one way is Grass Valley’s News Server accepting
HD-SDI input and re-encode using the new (soon available) JPEG2000 intra-frame.
JPEG2000 matches the full bandwidth of ProHD at local news quality HD at about
60Mbps with overheads, and at 4:2:2 and 10-bit pixel depth, will preserve the ProHD
overall image quality through the re-encode (and later decode). Grass Valley is in the
process of implementing full JPEG2000 support, including promoting Iomega’s
REV Pro (removable) hard disk cartridge as a recording sub-systems compatible
with JPEG2000 HD file storage, as an attractive and cost effective “on-the-shelf”
non-linear random access long term storage cartridge.
There is also Telestream’s FlipFactory, delivering a workflow automation solution
for broadcast and cable news, supporting the conversion of ProHD 720p60 transport
stream to several other formats upon ingest in a variety of NLEs and servers,
including DVCPRO-HD.
News Archive = Fast Retrieval – On line – Cost Effective
The ProHD compressed real time bitrate is only 20Mbps or 2.5MB/s, comprising full
bandwidth 1280x720p60. As stated earlier in this Report, the 80GB version of the
DR-HD100U stores about 6 hours (360 minutes) of ProHD or 4.5 minutes per GB.
10TB (10,000GB) disk arrays for video applications now sell for less than $10,000
with ProHD storage capacity of 45,000 minutes. That is 750 hours of news clips and
stories on line. If each clip is an average of 3 minutes, that’s 15,000 clips on line.
And at the low real time bitrate of only 20Mbps per clip, multiple concurrent reads
and writes of clips are achievable without bandwidth bottlenecks.
ProHD acquisition archive is automatic, as the camcorder records to the
internal HDV tape cassette concurrently with live-to-air and concurrently with
recording to the DR-HD100U hard disk unit.