SMPTE-292M 720p/1080i using a DVS HDstation or Centaurus. The Ultragrid software uses RTP with custom payload formats and profiles where necessary. An MTU of 8800 bytes is used. Various color formats (RGB, RGBA, BGR, BGRA, YUV) at various samplings (4:4:4, 4:2:2, etc.) are supported, as is DV (RFC 3189). The (open source) codebase runs under Linux (32-bit FC3). While back-to-back tests indicate an RTT of 70 microseconds for the transport of HD-SDI data, the actual end-to-end delay was estimated (subjectively) to be in the order of 0.5s. Slight variations of inter-frame display times were attributed to the Linux scheduler, for which the granularity might need to be reduced to 1ms.
Uncompressed SMPTE 292M @ 1080i using AJA Xena. The code is also capable of transporting HDCAM video (270 Mbps) and possibly HDV. The Australian AARnet has been collaborating with UW, adding support for the BlackMagic HD-SDI interface, which, while lacking in quality as an open source driver, is relatively inexpensive. Together, UW and AARnet ran a multipoint uncompressed demonstration for SC|04 (Pittsburgh) are are presently working on true multicast. Significant latency is attributed to the Xena video buffer, while a mminimum 6-frame delay is obtained through the BlackMagic interface. While there was some discussion of porting to Linux, the codebase remains a Windows system and is not RTP-compliant.
NTT's system supports 720p/1080i, unicast/multicast, IPv4/IPv6, and includes the capability of clock transmission for synchronization purposes. Versions with dual-headed GigE interfaces or a 10 GbE NIC (on PCI-X) are available. To reduce latency below the capabilities of the DVS product, NTT engineered their own HD-SDI interface (which runs on a PCI 66MHz/64 bit bus). HD-SDI transport latency as low as 0.5 frames is claimed although the system is normally run with 1 frame of delay to cope with jitter. The system is "somewhat" RTP-compliant. The i-Visto product has been integrated with NTT's eXmedia network storage system for the transmission of 10 simultaneous streams of uncompressed HD-SDI. At the NAB 2004, NTT demonstrated uncompressed HDTV + 2 SDTV signals transmitted bidirectionally with delay of less than 3 frames (Tokyo - Las Vegas); public demonstrations in Japan have featured 3 simultaneous streams for a high-school baseball competiion, and the linking of 4 points with 5 streams.
HDV MPEG-2 Transport Systems
MPEG-2 encoded high-definition resolution (1280x720p@30 or 1440x1080i) ranging from 19.2 to 28 Mbps via an IEEE1394 interface. Panasonic, Sony, and JVC all have products in this camera category. The Panasonic camera employs a 5-frame GOP encoding while the Sony uses 12. An encoding delay of approximately 1 - 1.5s must be added for video acquisition.- VideoLAN (France)
- Hydra (US - USC)
- IBM VideoCharger
- Pleora
- Streambox ACT-L3 (compresses true HD-SDI into a custom, compact format)
Consumer DV Transport Systems
- DVTS (WIDE, Japan): 25 Mbps DV stream (NTSC or PAL video) on IEEE1394 encapsulated into IP, with decoding in software or hardware, using the Fujitsu comet
Other Systems
- Gwangju Institute of Science and Technology (GIST, Korea) have based their HD-SDI stereo system on the Ultragrid code, using HDV cameras and a mount constructed by a third party industrial partner, whose outputs are upconverted to HD-SDI by an AJA HD10A A/D converter. Display is produced via an AJA HDP, which converts from HD-SDI to DVI-D.
- High-quality Video Service for Access Grid (GIST, Korea): provides a unified interface for diverse video clients
Last update: 26 February 2006