Section Two: Video Encoding Standards
Proprietary Formats (cont'd)

Progressive Networks' RealVideo (file format extension .rm or .ram) is a robust low-bandwidth format intended for Internet streaming. RealVideo is supported by a range of commercial and shareware products including encoding software, multimedia authoring tools, server software and client plug-ins. The G2 Real Media client supports SMIL synchronized text files, audio only, and plug-in extensions for MPEG. RealVideo is in widespread use and is supported by a complete client/server suite, including publishing, synchronized multimedia, and streaming server software, available in shareware and inexpensive commercial versions.

Other encoding formats proprietary to different manufacturers include Intel's Indeo© format and Cinepak, first developed by SuperMac Technologies and now owned by Radius.

M-JPEG is a quasi-standard provided by many video encoding cards. M-JPEG consists of sequential JPEG-encoded frames. JPEG stands for Joint Photographic Experts' Group and is the popular name for the still image encoding standard JFIF (JPEG File Interchange Format). JPEG is an intraframe compression standard intended for still images only. Video encoding cards provide M-JPEG compression so that the resulting digital video file may be edited. MPEG-1 and MPEG-2 files include I-frames, which are compressed intraframe, but also P-frames and B-frames, which do not include essential information, such as color or movement, but instead reference that information in a forward or backward frame. Since frame types are not eye-readable, video editing can result in the removal of critical reference frames. Some video cards now provide editable MPEG-1, eliminating the need for M-JPEG encoding. Editable MPEG-2 was introduced by Hewlett-Packard in 1997 for its HP MediaStream broadcast server.