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Proxy/live streaming technical details

The K2 Summit system writes proxy files to the proxy location specified in the GV STRATUS Control Panel application. On the specified device the location is V:\proxy\. For each clip recorded, the K2 system creates a directory and names it with the asset GUID, which is a long, unique string of characters. These directory names do not correspond to clip names or other human readable information. The directory contains the proxy files, which include the proxy video and audio files, as well as thumbnails files and a scene change file. The proxy video file is a fragmented MPEG-4 file. For test purposes, you can open the proxy file in a video player application that supports fragmented MPEG-4.

The K2 Summit system multicasts the low-resolution live stream using Real-time Transport Protocol, with UDP ports for the MPEG video with timecode and UDP ports for audio tracks, as defined by the Session Description Protocol (SDP). For each channel, the K2 system generates a *.sdp file that contains the streaming media initialization parameters. The K2 system updates the file whenever you change the live streaming configuration. You can find these files on the K2 system at V:\live streaming. For test purposes, you can open a file in a text editor and read the IP addresses and ports assigned to the multicast session and other configuration information for the stream.

The K2 Summit system can also generate low-latency streaming media for use by DynoZoom and live monitoring. Refer to related topics in the "Configuring the K2 System" section of the K2 Topic Library.

The K2 Summit system generates for each of its channels the specific live streaming network ports and IP addresses based on a port base and an IP address base. The port base is the first UDP port address for elementary streams. The IP address base is the first two octets in the IP address, as specified by the Internet Assigned Numbers Authority (IANA). By default, the port base is 31820 and the IP address base is With these default bases, the range of network ports is UDP 31820 to 31827 , and the range of IP addresses is 239.192.x.x to 239.195.x.x. Grass Valley recommends that you use these default settings. However, if necessary for your site's network policies, you can also change the K2 system's default settings. You can configure the port base and the IP address base. Only IP addresses specified by IANA for multicast are allowed. Do not attempt to edit the *.sdp files, as the K2 system generates them automatically whenever the system is restarted. If you change the IP address of the K2 system, you must restart in order to update the IP address in the *.sdp file.

The K2 Summit system hosts a simple web server over which it delivers the live stream via HTTP. For test purposes, you can access the live stream by entering a URL of the following convention in a standard web browser:


For example, to view the live stream from channel four on a K2 system named Summit01, the URL is http://Summit01/live/Summit01_C4.sdp. The http server name is the same as the name of the K2 system.

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