High-definition video recording in defence and aerospace applications Andrew Haylett
description
Transcript of High-definition video recording in defence and aerospace applications Andrew Haylett
10thNovember 2009
High-definition video recording in defenceand aerospace applicationsAndrew Haylett
2
Outline• 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
3
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
4
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
5
Analogue video recording• 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
6
‘Soft’ digital recording
‘soft’ digital recording system: uses graphics card to capture framestorewith simple software compression
7
‘Hard’ digital recording
uses custom hardware tocapture, compress and record
multiple video streams
8
Soft recording
• No extra hardware required
• Loads processor/graphics system
• Localized; not readily scalable across multiple sources
• Focuses on display video capture
Hard recording
• Hardware acquisition and compression
• Independent of rest of system
• Flexible scalable architecture includes entire installation
• Captures sensors, displays, metadata
‘Soft’ vs. ‘hard’ digital recording
9
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
10
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
11
Raw video bit rates
TV
HD
WSXGA
250Mbps110GB/hour
1400Mbps615GB/hour
2400Mbps1TB/hour
GbE = 1000Mbps
12
Raw video recording time
TV
HD
WSXGA
140 minutes
25 minutes
15 minutes
recording times assuming use of256GB memory cartridge
13
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 JPEG2000Improved compression and reduced artefacts, enhanced feature set, adopted by DoD NITF for highest quality storage
14
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
15
Frame-by-frame vs. inter-frame encoding
Intra-frame coding – uses only spatial redundancy
Inter-frame coding – uses spatial and temporal redundancy
I P P P PI
16
M-JPEG2000 vs. MPEG-4 AVC
JPEG2000• symmetric: encoding and
decoding computationally demanding
• intra-frame coding only• optimum for very high-
resolution images and synthetics
• decimation supported
• visually or mathematically lossless
MPEG-4 AVC• asymmetric: decoding
less computationally demanding
• inter- / intra-frame coding• optimum for medium to
high-resolution images
• decimation non-optimal• visually lossless only
JPEG-2000 vs. MPEG-4 AVC
17
Rugged implementations
HD JPEG2000 AC XMC card
TVJPEG2000 CC PMC card
18
Compressed video bit rates
TV 12Mbps5.5GB/hour
HD 70Mbps30GB/hour
WSXGA 120Mbps50GB/hour
GbE = 1000Mbps
TV 250Mbps110GB/hour
HD 1400Mbps615GB/hour
WSXGA 2400Mbps1TB/hour
assuming 20:1 compression ratio
19
Compressed video recording time
46 hoursTV
HD 8 hours
WSXGA 5 hours
TV 140 minutes
HD 25 minutes
WSXGA 15 minutes
recording times assuming use of256GB memory cartridge
20
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
21
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 locationsSolid state drives• ruggedisable, transportable, reliable, low mass• available as PCMCIA, CompactFlash,
PCIexpress, FiberChannel array up to 5TB• single rugged unit up to 512GB capacity
22
PCIexpress storage
Solid-state media
256GB removable cartridge512GB VPX3 module
CompactFlash module
23
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
platformRemovable• Can be swapped during operation if necessary• Convenient to transfer data to debrief station
24
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 codec-neutral and allows arbitrary metadata attachments to recorded files
• Key design elements are random access with rapid search, jump to event/time
25
Open container file
Header Video 1 Video 2 Video 1 Video 2
Audio1 Audio2 Video 1 Video 2 Metadata Metadata
Video 1 Video 2 Video 1 Audio1 Audio2
26
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 long-term media (e.g. Blu-Ray)
27
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
28
Example architecture
codervideo
networkswitch
GbE
recorder
GbE
GbE
decoder/display
GPS IRIG-B
29
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