
Netshow video server
A Technical Note
Authored by Terry Cornall
Date : 15/1/98
Report Number: CTIE-N-1998-002
- Microsoft Netshow V2.1
- Netshow is a Microsoft product for the production and delivery of audio/video multimedia across IP networks using TCP, UDP and HTTP. Both the server and the client software are available for free from Microsoft from http://www.microsoft.com/netshow/download.htm
- Note that there are actually two quite distinct servers: Netshow, for low bitrate delivery and Netshow Theatre, which is aimed at networks capable of better thatn 1.8Mbits/s.
- Information on product from http://www.microsoft.com/netshow
- Note that Netshow v3.0 is about to be released.
- Netshow server and asf tools.
- Microsoft NetShow v2.0 provides a mechanism to stream multimedia content across the Internet and intranets. It is made up of a server, administration tools, real-time encoder, content creation tools, and integration libraries (SDK's) to allow other software to access its capabilities.
- NetShow has support for the Macintosh, Windows 3.1, and UNIX operating systems.
- Netshow is capable of delivering multimedia encoded with a variety of compression methods and encapsulated in the ASF structure across low bitrate networks, down to 14 Kbits/sec, although the frame rate and resolution are very poor at this bandwidth, up to Mbit/s Lans. (See the section on Netshow Theatre below)
- ASF (Advanced Streaming Format)
- ASF by Microsoft is a container file format for multimedia that Netshow uses. It can contain audio and video, with synchronisation details, and also still images. It doesn’t specify a particular video or audio codec, that information is embedded in the content, which allows it to be used with a variety of compression methods, depending on the intended usage of the multimedia content.
- ASF editor
- The ASF editor allows the production of ASF files involving stills images, audio files and command scripts, although you can’t manipulate video files with it. (Use the real-time encoder to produce video ASF files)
- The editor gives the producer of multimedia presentations a visual representation of available and used bandwidth and time for the presentation and allows editing such as adding and synchronising media content and command scripts before building and testing the resulting ASF file.
- Included are a useful sample project and a short overview tutorial presented as an ASF file with screen shots and audio explanations. The tutorial is useful as an introduction, but the user definitely has to refer to the on-line help and outside sources of reference material.
- The ASF editor can also be used with Microsoft Powerpoint for production of presentations.
- ASF real-time encoder
- This tool allows the encoding of live audio/video or AVI files into ASF files that can be stored or transmitted to a Netshow server, or both, in real-time. This means that with a camer and microphone attached to the computer, a user can produce ASF assets as the events occur or that they can capture to an AVI file and compress and convert to ASF later.
- Various bandwidth usage profiles are provided to allow the quick selection of compression parameters and advanced customisation is also enabled to allow more detailed specification of performance to match available bandwidth and other factors such as amount of motion in the video.
- Codecs
- The following list details the audio and video codecs that ship with Netshow. Keep in mind that this list will certainly change with time, and that not all the codecs will work properly. (See the section on codec problems below)
- Audio
- Lernaut & Hausie CELP 4.8Kbit/s Encode +Decode
- Mpeg Layer-3 Encode+Decode
- Vivo G.723.1 Standard complient Decode only
- Vivo Siren Decode only
- Voxware Metasound Encode+Decode
- Voxware Metavoice Encode+Decode
- Video
- Clear Video Encode (With Osprey 1000 card) + Decode
- Duck TrueMotion RT Encode + Decode
- Intel H.263 Encode (Decode using Vivo H.263 decoder)
- Vivo H.263 Decode only
- Microsoft MPEG-4 Encode+Decode
- VDONet VDOWave Encode+Decode
- Known codec problems
- NOTE: According to Microsoft, the following audio and video codecs don’t work with the V2.0 ASF Editor. Don’t use them for compression of the output file, although they may work as input formats. Comparing this list to the list above indicates that for video, Intel H.263, VDOWave and Clear Video seem to be the only choices left. For Audio, Lernaut & Hausie, Mpeg L-3 and the Voxware codecs (But only the file codecs, not bitstream)
- Problem Encoding Audio in V2.0 ASF Editor:
- Netscape compatible RT24
- Microsoft G.723.1
- Vivo Siren
- Voxware Bitstream or Non-file codecs
- VivoActive G.723.1 (Decode only)
- Problem Encoding Video in V2.0 ASF Editor:
- MPEG-4 Video High Speed Compressor
- Microsoft H.263 Video Codec
- Vivo H.263 (Is a decoder only)
- Duck Truemotion RT 2.0
- Netshow Theatre
- Microsoft NetShow Theater Server is a high-performance streaming media video server designed for high bandwidth networks, such as ATM intranets, providing a method to deliver MPEG-quality full-motion, full-screen video.
- Capable of 30 frames per second, full-screen video if the network can support 1 Mbits per second or better.
- Scalable and fault-tolerant architecture.
- Netshow with Real audio/video
- Enables Netshow to be compatible with a lot of existing material produced using RealVideo and RealAudio software. It is claimed by Microsoft that: “By adding to Microsoft NetShow the ability to create, serve, and play live and on demand ASF and RealAudio/RealVideo content, over 95% of the streaming media content on the Web can be accessed using NetShow.”
- Includes support for RealAudio 4.0 and RealVideo 4.0 content and features the ability to create and serve both live and on-demand content.
- Is based on the RealAudio and RealVideo servers developed by Real Networks.