RealVideo
RealVideo is the proprietary video format of Real Media and how RealAudio from RealNetworks developed and patented. It is mainly used in streaming applications.
Files compressed with RealVideo are lossy . The quality of RealVideo files is generally comparatively good with high compression, older versions are poor with low compression compared to MPEG, for example . In terms of quality, however, newer versions are comparable to MPEG-4 video codecs such as Xvid or DivX , as well as Windows Media Video 9.
Open source implementations exist in the FFmpeg project for all published RealVideo versions . For RealVideo 5 ( RV10 ) and RealVideo G2 ( RV20 ) decoders and encoders, for the newer versions only decoders.
Since the introduction of RealVideo 9 and the start of the Helix community at the end of 2002 to 2008, the then main developer of the RealVideo format, Karl Olav Lillevold, maintained direct contact with end users through the Doom9 forum, where he gave precise help on using the RealVideo codecs. During this time, the encoder was updated at shorter intervals. The development of RealVideo 11 was discontinued and associated patents were sold to Intel at the beginning of 2012 . Since then (as of July 2015) RealNetworks has stopped developing video codecs.
There are currently four mutually incompatible versions of RealVideo, which are identified by a four-letter code , as also occurs in AVI format :
- RV10 : RealVideo 5, the first version of RealVideo, the format is identical to H.263
- RV20 : RealVideo G2; RealVideo G2 + SVT
- RV30 : RealVideo 8
- RV40 : RealVideo 9; RealVideo 9 EHQ; RealVideo 10
Various developers accuse RealNetworks of not having developed the formats independently, but merely copying slightly modified - and thus incompatible - industry standards (or their preliminary versions) such as H.263 and H.264 .
RealVideo usually appears in the RealMedia container and then has its file extension .rv, .ram, .rm, or .rmvb; the MIME type is audio / x-pn-realvideo . However, it can also be used in Matroska (file extension .mkv).
RealVideo can be created by the Helix-Producer, which is available free of charge for various operating systems . For the program, which can only be controlled by configuration files and the command line , there are various front ends that even beginners can use.