Audio File Features Audio file is a record of captured sound that can be played back –The WAV File is an example Audio files are compressed for storage and faster transmission Requires high bandwidth to transfer across the network and the Internet
The Wav File Format The wav file format is also known as the basic file format –Somewhat similar to the.bmp format for images Requires the highest storage compared to other compressed and streamed file formats –Example: rm, wma etc.
Audio Streaming Concept.WAV.ASF,.WMA Real Producer. RM Windows Media Encoder or Real Producer PC Audio Format PC Windows Media Streaming Software
Audio Streaming Step1: Digitize audio –PCM Step 2: Compress the digitized audio –Lowering the audio’s sampling rate –Filtering high frequencies –Performing other waveform transformation Ensure the continuous streaming of audio packets
Pulse Code Modulation Values Sampling Frequency –11,000 Hz for example Sampling depth –8 bits for example Channels –Mono or stereo
Audio Streaming Products Window Media Technologies (Microsoft) Real System (Real Networks) Shockwave Streaming Audio (Macromedia) Linux based streaming products
Windows Media Technologies Windows Media Audio 9 Series Windows Media Video 9 Series Windows Media Encoder 9 Series Windows Media Services 9 Series Windows Media Player 9 Series Windows Media Rights Manager 9 Series Windows Media 9 Series SDK
Windows Media Link http://www.microsoft.com/windows/w indowsmedia/http://www.microsoft.com/windows/w indowsmedia/
Windows Media Technologies (WMT) Windows Media Audio CODEC provides excellent quality at low bit rates Integration with other Microsoft products (Windows NT Server, Microsoft Site Server, Microsoft BackOffice) Digital rights management Advanced Compression Technology Broadcasting
WMT Advantages Multiple Bit Rate and Multiple Language Support Variable speed playback Highly compressed audio and video Audio CODEC is optimized for dial-up rates Digital 5.1 surround sound CODEC Lossless audio compression Good scalability to larger audience Live digital rights management Support for Plug-in (C++ etc.) (For further info: )
Multiple Bit Rate and Multiple Language Support With a single click of one file, the Windows Media Player 9 Series can automatically pick the best video size and audio quality to stream, based on the current connection speed – and it dynamically adapts during streaming. The player can automatically choose the preferred audio language, or the user can select or change languages on-the-fly during playback. (source: Microsoft)
Real Networks High quality streaming audio at all bandwidths on both the Internet and corporate Intranets. Support realtime and on-demand, all sounds (stereo and mono) Take advantage of key features of Window 2000 (load balancing, clustering, stability) Operating systems such as Window NT, Linux, Sun Solaris etc. are all supported
Real System G2 Products & Advantages RealPlayer 8 –Over 150 live radio stations built-in, superb audio RealProducer 7 –Streaming Software; Efficient encoding; Reach the widest possible audience; choice of operating systems RealPresenter G2 –Live/recorded capability; Presentation Manager
RealSystem G2 Products & Advantages RealSlideshow 2 –Combine pictures with music or speech, customize the layout of presentation RealServer 7 –60 simultaneous sessions of live or on-demand streaming; Near CD quality Internet audio Free download at: –http://www.realnetworks.com/products/
Video Streaming Video Streaming Objective Streaming Advantages Video Streaming Architecture Compression and Decompression-codec MPEG 1-4 Introduction Major Products and Features Comparison
Video Streaming Objective The object is to overcome the negative effects of physical distance and network technology limitation.
Streaming Advantages Reduce setup time Reduction in client storage requirement Video can be viewed in real time Transmission signals over low bandwidth facilities
Video Streaming Architecture Content Creation/Capture Content Management Content Formatting (Compression) Delivery Distribution Presentation (Viewing) View Control
Video Capture Converting analog to video signals –A special video capture card to convert the analog signals to digital form and compresses the data. –Also digital video devices that can capture images and transfer to a computer
Content Management Critical in video server The purpose including create, collect, catalog, organize, store, and access to massive multimedia information database
Video Input Formats AVI ActiveMovie Cinepak Indeo motion-JPEG MPEG QuickTime RealVideo Video for Windows XGA
Video Formats AVI & ASF Developed by Microsoft AVI (Audio Video Interleaved) - limited to 320x240 resolution - 30 frames per second ASF (Advanced Streaming Format) - Has been submitted to ISO for standardization - Expected to replace AVI format
Frame Rates 4-6 fps –Absolute minimum for video conferencing 11-14 fps –The norm for video conferencing 30 fps –Full motion video
Codec (Compressor/Decompressor) Coding techniques to compress video data The newest codec change their sampling rate as they run Choice of codec is the biggest factor to determine the bandwidth needed to connect the server and receive content Many of the codecs follow international standards
Content Compression MPEG (A working group of ISO) - The most common standard for video compression and file formats - Generally produce better quality video than other formats - High compression rate - MPEG1, MPEG2, MPEG3 and MPEG4
MPEG-1 MPEG-1 was designed for coding progressive video at a transmission rate of about 1.5 million bits per second. It was designed specifically for Video-CD and CD-i media. MPEG-1 audio layer-3 (MP3) has also evolved from early MPEG work.
MPEG-2 MPEG-2 was designed for coding interlaced images at transmission rates above 4 million bits per second. MPEG-2 is used for digital TV broadcast and DVD. An MPEG-2 player can handle MPEG-1 data as well.
MPEG-3 A proposed MPEG-3 standard, intended for High Definition TV (HDTV), was merged with the MPEG-2 standard when it became apparent that the MPEG-2 standard met the HDTV requirements.
MPEG-4 An MPEG-4 standard is in the final stages of development and release. It is a much more ambitious standard and addresses speech and video synthesis, fractal geometry, computer visualization, and an artificial intelligence (AI) approach to reconstructing images.
Major Products Microsoft Windows Media Technologies http://www.microsoft.com/windows/window smedia/ RealSystem G2 http://www.realnetwork.com
Comparison WMT –vs- RealSystem G2 Head to head comparison Feature Comparison More Information http://www.microsoft.com/windows/windo wsmedia/ http://www.microsoft.com/windows/windo wsmedia/
Comparison WMT –vs- RealSystem G2 Cost Analysis - Prepared by Approach, Inc., Key findings - Both streaming products results in positive returns on investment - Microsoft solution is more economical than the RealNetwork solution Download in Word formatDownload
Audio Streaming Architecture Creating Audio File Demonstration of Streaming Software Demo of Streaming Process –Windows Media Encoder –RealProducer 7 Basic Play the Audio File
Creating Audio File Record From File –Audio files located in your hard drive Record Form Media Device –Media device such as Microphone, CD Player, PC Camera, etc. Live Broadcast –Broadcast live media stream from your computer
Installation of Streaming Software Windows Media Tools –Windows Media Encoder RealSystems G2 –RealProducer 7 Basic
Windows Media Technologies http://www.microsoft.com/windows/windowsmedia Download Windows Media Tools
Video Streaming Live feed Video Capture. - C:\Program Files\Logitech\Logitech QuickCam\QuickCam.exe C:\Program Files\Logitech\Logitech QuickCam\QuickCam.exe Stream from live feed. - C:\Program Files\REAL\RealProducer\realprod.exe C:\Program Files\REAL\RealProducer\realprod.exe - C:\Program Files\Windows Media Components\Tools\NsRex.exeC:\Program Files\Windows Media Components\Tools\NsRex.exe
Audio/Video Streaming Summary Capture Audio/Video –Create your file Install the streaming software –Windows Media Tools http://www.microsoft.com/windows/windows media/ http://www.microsoft.com/windows/windows media/ –RealProducer 7 Basic http://www.realnetworks.com/products/ http://www.realnetworks.com/products/
Audio/Video Streaming Summary Play the Audio Stream File –Windows Media Player 7 http://www.microsoft.com/windows/window smedia/ http://www.microsoft.com/windows/window smedia/ –RealPlayer 7 Basic http://www.real.com/player/index