Video over IP
May 1, 2009 12:00 PM, By Brad Gilmer
New standards allow broadcasters to use video over IP for video transport.
The Video Services Forum (VSF) is currently working on several additions to SMPTE 2022. The first item is a scheme for transmission of variable bit rate (VBR) MPEG-2 streams over IP networks with FEC. This adds VBR transmission to the 2022 repertory. The VSF is also working on two additional documents that will cover high bit rate uncompressed transmission (HD) over IP and JPEG2000 compressed video over IP. Finally, the group is preparing a new FEC document that addresses the protection of the transmission of high bit rate streams on IP networks.
The European Broadcast Union is working on a document that will address standardized transmission of JPEG2000 streams encapsulated in MXF. The VSF and the EBU are working together to harmonize the approach to all of these standards in the hopes that manufacturers can make equipment that easily supports several of these transmission modes. (See Table 1.)
How real is video over IP?
All of this standards activity is fine, but can broadcasters actually purchase video-over-IP equipment that works? The answer is yes. Several manufacturers make SMPTE 2022-compliant products that move the video as compressed CBR MPEG-2 transport streams from one location to another over IP networks.
There is equipment available that moves JPEG2000 compressed high bit rate streams encapsulated in MXF files too, but as of yet, this equipment is not standardized because work on the standard is not complete.
When asking whether video over IP is real, you must also ask what sort of network is needed in order to use this equipment. These standards were designed with well-managed IP networks in mind. Before the work started, the VSF surveyed its members to determine what sort of well-managed IP connections were available to broadcasters. It turns out that if you know what to ask for, the links are pretty good. The VSF wrote these documents assuming that the equipment would be used on well-managed IP networks. The standards were not written with the generic Internet in mind.
Your transport carrier has products that work well and can support video over IP reliably. Furthermore, when that network capacity between facilities is not being used for video over IP, it can be pressed into service for other needs, such as to transfer large files or to provide IP telephony.
Brad Gilmer is executive director of the Video Services Forum, executive director of the Advanced Media Workflow Association and president of Gilmer & Associates.
Table 1. Standards and work in progress for video over IP
| Standard | Short title | Status |
|---|---|---|
| SMPTE 2022-1 | CBR FEC | SMPTE standard |
| SMPTE 2022-2 | CBR MPEG-2 TS over IP | SMPTE standard |
| Not assigned | VBR MPEG-2 TS over IP | Submitted to SMPTE |
| Not assigned | Uncompressed high bit rate video over IP | In process at the VSF |
| Not assigned | JPEG2000 compressed video over IP | In process at the VSF |
| Not assigned | JPEG2000 compressed video encapsulated in MXF | In process at the EBU |
Send questions and comments to: brad.gilmer@penton.com
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