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32-404: RealVideo is usually paired with RealAudio and packaged in a RealMedia (.rm) container. RealMedia is suitable for use as a streaming media format, that one is viewed while it is being sent over the network. Streaming video can be used to watch live television since it does not require downloading the entire video in advance. The first version of RealVideo was announced in 1997 and was based on

64-674: A filename extension of .ra (for Real Audio). In 1997, RealNetworks also began offering a video format called RealVideo. The combination of the audio and video formats was called RealMedia and used the file extension .rm . However, the latest version of RealProducer, Real's flagship encoder, reverted to using .ra for audio-only files, and began using .rv for video files (with or without audio), and .rmvb for VBR video files. The .ram (Real Audio Metadata) and .smil (Synchronized Multimedia Integration Language) file formats are sometimes encountered as links from web pages (see .Streaming Audio section below). The official player for RealMedia content

96-576: A higher bit rate. If the bit rate of a video stream increases significantly, it may exceed the speed at which data can be transmitted over the network, leading to an interruption in the video. RealNetworks says that the RealVideo and RealAudio codecs are not available in source code under the RPSL license. Source code is available only under RCSL license for commercial porting to non-supported processors and operating systems. While RealNetworks owns most of

128-479: A media encoding engine for creating streaming broadcasts, on-demand streaming content, and downloadable audio video files. The Helix DNA Producer runs on MS Windows, Linux and Mac OS X. The Helix DNA Producer contains output support for the following data types: Developers who want MP3 encoding can license the code from RealNetworks for a fee. There is also an add-on package for Helix DNA Producer SDK with AAC or aacPlus encoding support. Helix DNA Producer

160-499: A proprietary protocol called PNA or PNM to send streaming audio data. RealNetworks later switched to the IETF standardized Real Time Streaming Protocol (RTSP) but they use RTSP only to manage the connection. The actual audio data is sent with their own proprietary RDT protocol, which they initially kept secret. Recently, some specifications for the RDT protocol have been made public through

192-523: Is RealNetworks' RealPlayer SP , currently at version 16, and is available for various platforms in binary form. Several features of this program have proven controversial (most recently, RP11's ability to record unprotected streaming media from web sites), and many alternative players have been developed. RealNetworks initially tried to discourage development of alternative players by keeping their audio format secret. However, in recent years, RealNetworks has made efforts to be somewhat more open, and has founded

224-530: Is RealPlayer 8; but this version can be easily modified to play RealPlayer 9 and 10 files, by the manual addition of just three .dll files (codecs and plugins), from Microsoft's free distribution of RealPlayer 10, that are not included in RealPlayer 8 Basic. RealNetworks has also developed the open-source Helix player , however support for RealVideo in the Helix Project is limited because RealNetworks

256-479: Is a proprietary audio format developed by RealNetworks and first released in April 1995. It uses a variety of audio codecs , ranging from low-bitrate formats that can be used over dialup modems, to high-fidelity formats for music. It can be used as a streaming audio format, that is played at the same time as it is downloaded. In the past, many internet radio stations used RealAudio to stream their programming over

288-483: Is a software package for multi-platform, multi-format media playback. Helix Player is a media player compatible with Linux , Solaris , Symbian , and FreeBSD and uses the Helix DNA Client. The Helix DNA Producer application aids in producing media files, and Helix DNA Server can stream media files over a network. The code is released in binary and source code form under various licenses, notably

320-476: Is also a commercial version called Helix Server, which has more features and supports more media formats. It was originally called the Helix Universal Server when it was announced in or before 2002. It is based on the Helix DNA Client. It is available for Linux, Solaris, Symbian and FreeBSD. Users of Microsoft Windows and Mac OS X can use RealPlayer, which has similar capabilities. It is

352-415: Is identified by a four character code . Below is a list of the codecs and the version in which each was introduced: While the newest version of RealPlayer should be able to play any RealAudio file, other programs may not support all codecs. Helix player Helix DNA was a project to produce computer software that can play audio and video media in various formats and aid in creating such media. It

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384-472: Is identified by a four-character code . Below is a list of the video compression formats and the version in which each was introduced: The newest version of RealPlayer can play any RealVideo file, as can programs using FFmpeg . Other programs may not support all video compression formats. In addition to decoder code for up to RV50, FFmpeg also contains open-source code for RV10 and RV20 encoders. RealAudio RealAudio , also spelled Real Audio ,

416-528: Is still keeping the codecs proprietary. RealPlayer does not record RealVideo streams, and RealNetworks has advertised this feature to content owners such as broadcasters, film studios, and music labels, as a means of discouraging users from copying video. However, other software exists which can save the streams to files for later viewing. Such copying, known as time-shifting , is legal in most countries. RealVideo files are compressed using several different video compression formats . Each video compression format

448-495: Is supplied as a library which is included within Android Java applications for over the air installation. Helix DNA client contains support for the following media formats: The Helix DNA Server, first released on 22 January 2003, supports streaming of following formats: It supports streaming to any device or application that supports HTTP , RTSP / RTP , TCP, UDP unicast and UDP multicast streaming protocols. There

480-542: The H.263 format. At the time, RealNetworks issued a press release saying they had licensed Iterated Systems ' ClearVideo technology and were including it as the RealVideo Fractal Codec. However, support for ClearVideo quietly disappeared in the next version of RealVideo. RealVideo continued to use H.263 until RealVideo 8 when the company switched to a proprietary video format. RealVideo codecs are identified by four-character codes . RV10 and RV20 are

512-497: The Helix Community project. By around 2004 the open-source MPlayer project developed a means of playing the RDT streams. In many cases, web pages do not link directly to a RealAudio file. Instead, they link to a .ram (Real Audio Metadata) or SMIL file. This is a small text file containing a link to the audio stream. When a user clicks on such a link, the user's web browser downloads the .ram or .smil file and launches

544-528: The Helix Community , a collaborative open source project, to extend their media framework. When RealAudio was introduced, RealNetworks disclosed no technical details about the audio format or how it was encoded, but it was soon noticed that some of the audio codecs used in RealAudio were identical to those used in cellular telephones and digital television . As these formats had been described in detail in various technical papers and standards documents, it

576-520: The IETF . However, RealNetworks uses RTSP only to set up and manage the connection. The actual video data is sent with their own proprietary Real Data Transport (RDT) protocol. This tactic has drawn criticism because it made it difficult to use RealVideo with other player and server software. However, the open-source MPlayer project has now developed software capable of playing the RDT streams. To facilitate real-time streaming, RealVideo (and RealAudio) normally uses constant bit rate encoding, so that

608-663: The Internet Tablet OS from Nokia , which is found on the Nokia 770 , N800 and N810 Internet Tablets. Cingular Video is also based on the framework. Other projects that use the Helix framework include RealNetwork's Rhapsody online music service, the Banshee and Amarok music players, and MediaReady 4000. Helix DNA also manifests itself as the RealPlayer on Mobile Internet Devices (MID) and on Netbooks. Developers from

640-690: The Open Source Lab announced in 2007 they would use Helix technologies for content creation applications and collaboration in the One Laptop Per Child project. Helix DNA client contains support for the following media formats: Helix DNA Client for Android provides an HLS, MPEG-DASH, Verimatrix DRM and Microsoft PlayReady DRM media player for Android 2.2 to latest devices. Supporting H.264 and AAC codecs with Adaptive Bit Rate support (H.264 / AAC) including audio only. Armv7 and Armv6 supported using Stagefright media platform. Helix SDK

672-399: The dynamically linked libraries (DLLs) from the official RealPlayer to play the video, and thus require RealPlayer to be installed (or at least its DLLs, if not the actual player). However, FFmpeg 's libav* libraries (and its DirectShow counterpart ffdshow ) can play RealVideo and do not require RealPlayer or any parts thereof. The latest version of RealPlayer that can run on Windows 9x

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704-609: The proprietary RealNetworks Community Source License and the free and open source software RealNetworks Public Source License. Additionally, the Helix DNA Client and the Helix Player are licensed under the popular GNU General Public License (GPL) free and open source license. Use of the RDT , the default proprietary Real data transport, and of the RealVideo and RealAudio codecs requires binary components distributed under

736-528: The H.263-based codecs. RV30 and RV40 are RealNetworks' proprietary H.264-based codecs. These identifiers have been the source of some confusion, as people may assume that RV10 is RealVideo version 10 when it is the first version of RealVideo. RealVideo 10 uses RV40. RealVideo can be played from a RealMedia file or streamed over the network using the Real Time Streaming Protocol (RTSP), a standard protocol for streaming media developed by

768-540: The Helix DNA Technology Binary Research Use License. Helix DNA Client powers many digital media applications, including RealPlayer for MS Windows, Mac OS and Linux (since version 10), RealPlayer Mobile, and Helix Player. It is used on Nokia , Motorola , Samsung and Sony Ericsson mobile phones. 800 million mobile phones with the Helix client have been shipped since 2004. It is also being used in embedded devices like

800-529: The intellectual property for RealVideo and RealAudio, RealNetworks has licensed third-party technology for certain aspects of those codecs. RealNetworks claims that it does not have the right to license that technology under an open-source license. The official player for RealVideo is RealNetworks RealPlayer SP , currently at version 15, and is available for various platforms including Windows , Macintosh , and Linux . Several other players exist, including MPlayer and Media Player Classic . Many of these rely on

832-551: The internet in real time. In recent years, however, the format has become less common and has given way to more popular audio formats. RealAudio was heavily used by the BBC websites until 2009, though it was discontinued due to its declining use. BBC World Service , the last of the BBC websites to use RealAudio, discontinued its use in March 2011. RealAudio files were originally identified by

864-419: The publicly available information about the formats, and do not use the RealPlayer or Helix software. It is also possible to obtain codecs which allow Windows Media Player to play some versions of RealAudio. Although RealNetworks has made the Helix player available as an open source project, they have kept some of the audio codecs proprietary, and the Helix player can not play all RealAudio files. RealAudio

896-416: The same amount of data is sent over the network each second. Recently, RealNetworks has introduced a variable bit rate form called RealMedia Variable Bitrate ( RMVB ). This allows for better video quality, however, this format is less suited for streaming because it is difficult to predict how much network capacity a certain video stream will need. Video with fast motion or rapidly changing scenes will require

928-474: The user's media player. The media player reads the PNM or RTSP URL from the file and then plays the stream. With RealPlayer SP , it is now possible to save an audio stream to a file. Other programs, including MPlayer , RM Downloader , VLC media player , StreamBox VCR , HiDownload and Real7ime Converter can also save streams to a file. RealAudio files are compressed using several audio codecs . Each codec

960-523: Was developed as a streaming media format, meaning that it can be played while it is downloaded. It is possible to stream RealAudio using HTTP . In this case, the RealAudio file is retrieved similarly to a normal web page, but playback begins as soon as the first part is received and continues while the rest of the file is downloaded. Using HTTP streaming works best with pre-recorded files so some alternative protocols have been developed which work better for live broadcasts. The first version of RealAudio used

992-458: Was intended as a largely free and open-source digital media framework compatible with numerous operating systems and processors (including mobile phones) and it was started by RealNetworks , which contributed much of the code. The Helix Community was an open collaborative effort to develop and extend the Helix DNA platform. The Helix Project has been discontinued. Helix DNA Client

RealVideo - Misplaced Pages Continue

1024-563: Was possible to write software capable of playing RealAudio based on this information. A variety of unofficial players now exist, including MPlayer , and Real Alternative . However, Real Alternative does not decode the audio data by itself, but relies on the dynamically linked libraries (DLLs) from the official RealPlayer. Thus Real Alternative requires RealPlayer to be installed (or at least its DLLs) in order to function. Most other players are based on FFmpeg , which has its own audio codec library. The audio codecs in ffmpeg were written based on

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