Transcript Slide 1

High-definition video recording in defence
and aerospace applications
Andrew Haylett
10thNovember 2009
Outline
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introduction and platforms
technology review – analogue and digital
‘hard’ versus ‘soft’ recording
video interfaces and metadata
raw video bit rates and recording time
video compression technologies
storage media
recording file formats
the replay/debrief facility
digital video distribution
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Introduction – the need
• acquisition and storage of video signals a key
feature of modern defence applications
• new sensor/camera technology brings higher
resolution images
• need to capture complex displays as well as
multiple sensors and complex metadata
• application areas include training, debrief and
forensics
• solution must be rugged, cost-effective and
scaleable, minimizing size, weight and power
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Typical platforms
• US air: Joint Strike Fighter, P-8A
Poseidon
• UK air: Nimrod MRA4
• US land: Bradley Fighting Vehicle,
Abrams Tank, Stryker family
• UK land: Warrior armoured vehicle
• Many platforms undergoing
modernization and capability
enhancement
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Analogue video recording
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mechanical ruggedization a challenge
limitations on media capacity and recording time
limited video resolution and quality
difficult to make acceptable copies
vulnerable to electrical interference
access is sequential rather than random
cannot easily scale to multiple video streams
cannot achieve comprehensive data fusion
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‘Soft’ digital recording
‘soft’ digital recording system: uses
graphics card to capture framestore
with simple software compression
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‘Hard’ digital recording
uses custom hardware to
capture, compress and record
multiple video streams
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‘Soft’ vs. ‘hard’ digital recording
Soft recording
Hard recording
• No extra hardware
required
• Loads processor/graphics
system
• Localized; not readily
scalable across multiple
sources
• Focuses on display video
capture
• Hardware acquisition and
compression
• Independent of rest of
system
• Flexible scalable
architecture includes
entire installation
• Captures sensors,
displays, metadata
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Video interfaces
Analogue
• Composite/RGB TV (NTSC/PAL), including
STANAG 3350
• High-resolution analogue RGB – VGA to WUXGA
(1920 x 1200)
Serial digital
• DVI/HDMI
• Firewire (IEEE 1394), CameraLink, USB
• SD-SDI, HD-SDI (SMPTE 292M)
• GigE Vision – video over GbE
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Metadata and audio
Need to capture events or data streams from
multiple sources
• Operator-initiated signalling of events
• Navigational data (GPS)
• Time source (IRIG-B)
• MIL-STD-1553/1773, MilCAN, ARINC 429, GbE
• Data streams should be reconstituted or stored at
debrief station
• Recordings should be searchable by metadata
• Support multiple audio channels
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Raw video bit rates
GbE = 1000Mbps
TV
250Mbps
110GB/hour
1400Mbps
615GB/hour
HD
WSXGA
2400Mbps
1TB/hour
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Raw video recording time
TV
HD
WSXGA
140 minutes
25 minutes
15 minutes
recording times assuming use of
256GB memory cartridge
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Video compression technologies – JPEG
• JPEG (ISO/IEC IS 10918-1), M-JPEG
Widely used, performs well for photographic
images, suffers from artefacts at high
compression
• JPEG2000 (ISO/IEC 15444), Motion JPEG2000
Improved compression and reduced artefacts,
enhanced feature set, adopted by DoD NITF for
highest quality storage
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Video compression technologies – MPEG
• MPEG-2 (ISO/IEC 13818)
Widely used in consumer applications including
broadcast TV and DVD
• MPEG-4 (ISO/IEC 14496)
Adds extra coding complexity to deliver improved
compression
• MPEG-4 Part 10 Advanced Video Coding (ITU
H.264)
Used on high-definition DVD; current standard for
low bitrate encoding
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Frame-by-frame vs. inter-frame encoding
Intra-frame coding – uses only spatial redundancy
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Inter-frame coding – uses spatial and temporal redundancy
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JPEG-2000 vs. MPEG-4 AVC
JPEG2000
MPEG-4 AVC
• symmetric: encoding and • asymmetric: decoding
M-JPEG2000
vs. MPEG-4 AVC
decoding computationally
less computationally
demanding
demanding
• intra-frame coding only
• inter- / intra-frame coding
• optimum for very high• optimum for medium to
resolution images and
high-resolution images
synthetics
• decimation supported
• decimation non-optimal
• visually or mathematically • visually lossless only
lossless
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Rugged implementations
TVJPEG2000 CC PMC card
HD JPEG2000 AC XMC card
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Compressed video bit rates
GbE = 1000Mbps
12Mbps
250Mbps
5.5GB/hour
110GB/hour
TV
HD
70Mbps
HD
30GB/hour
WSXGA
120Mbps
50GB/hour
1400Mbps
615GB/hour
WSXGA
2400Mbps
1TB/hour
assuming 20:1 compression ratio
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Compressed video recording time
TV
140 minutes
TV
46 hours
HD
HD 25 minutes
8 hours
WSXGA
WSXGA15 minutes
5 hours
recording times assuming use of
256GB memory cartridge
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Storage media – requirements
Requirements for military / aerospace
applications
• mechanically robust
• withstand extreme environments: shock,
vibration, temperature, humidity
• high reliability and long life
• maximum storage capacity
• easily transportable
• security of recorded data
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Storage media – alternatives
Conventional magnetic disks
• single units up to 2TB capacity
• need careful system design to protect from
environment
• not ideal for transport between locations
Solid state drives
• ruggedisable, transportable, reliable, low mass
• available as PCMCIA, CompactFlash,
PCIexpress, FiberChannel array up to 5TB
• single rugged unit up to 512GB capacity
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Solid-state media
PCIexpress storage
CompactFlash module
256GB removable cartridge
512GB VPX3 module
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Fixed or removable?
Fixed
• Potentially greater capacity available
• Easier to design for rugged environment
• Streaming off recorder time-consuming
• Problems of security if sensitive data left on
platform
Removable
• Can be swapped during operation if necessary
• Convenient to transfer data to debrief station
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Recording file formats
• Common formats include AVI (Windows standard),
MPG (MPEG-2/4) – support for video and audio
• Ideal format will encompass video, audio and
metadata
• Open file formats support any video encoding
standard; e.g. the Matroska MKV format is codecneutral and allows arbitrary metadata attachments to
recorded files
• Key design elements are random access with rapid
search, jump to event/time
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Open container file
Header
Audio1
Video 1
Video 1
Audio2
Video 1
Video 2
Video 2
Video 2
Video 1
Video 1
Video 2
Metadata
Audio1
Metadata
Audio2
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Replay / debrief facility
• Typically based on COTS equipment, e.g.
desktop PC
• May use software decoder or hardware
accelerator depending on compression
asymmetry and graphics card capability
• Will provide scaled multi-window presentation
with jump to arbitrary time and metadata search
• Will accept removable media from recording
system and optionally support archival to longterm media (e.g. Blu-Ray)
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Digital video distribution
• Video recording and video distribution closely related
• Video streams transferred to digital domain may be
easily sent point-to-point or broadcast over standard
network infrastructure
• Video over IP is readily scalable to emerging
technologies such as 10GbE
• Video recorder becomes node on digital video
distribution network
• Standard video distribution protocols such as RTP
provide quality of service and encapsulation of
various compression formats
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Example architecture
video
decoder/
display
coder
GbE
GbE
network
switch
GbE
GPS
IRIG-B
recorder
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Conclusions
Digital video recording offers:
• Environmentally robust solution with emphasis on
cost, size, weight, power
• Enhanced recording time and video quality
• Advanced features such as play-while-recording,
record only last N hours of mission
• Integrates sensor video, display video, audio,
events and metadata into single stream
• Scalable to high sensor density
• Part of comprehensive video distribution system
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Any questions?
Andrew Haylett
[email protected]
01462 472537
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