REALSYSTEM™ G2 PRODUCTION GUIDE
`RealSystem G2, Release 7
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`NEULION 1002
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`Information in this document is subject to change without notice. Companies, names, and data used in
`examples herein are fictitious unless otherwise noted. No part of this document may be reproduced or
`transmitted in any form or by any means, electronic or mechanical, for any purpose, without the express written
`permission of RealNetworks, Inc.
`©1998-2000 RealNetworks, Inc.
`The Real logo, RealNetworks, RealAudio, RealVideo, RealText, RealBroadcast Network, RBN, RealServer,
`RealPlayer, RealJukebox, RealPresenter, RealStore.com, RealProducer, RealPublisher and RealSystem, Real.com,
`and Real.com Take5 are registered trademarks of RealNetworks, Inc.
`RealG2 with Flash is a trademark of Macromedia, Inc. and RealNetworks, Inc.
`Macromedia is a registered trademark and Flash and Shockwave are trademarks of Macromedia, Inc.
`All other products and companies listed herein are trademarks or registered trademarks of their respective
`owners.
`
`RealNetworks, Inc.
`2601 Elliott Avenue
`Seattle, WA 98121 USA
`
`http://www.realnetworks.com
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`CONTENTS
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`INTRODUCTION
`How this Manual is Organized ............................................... 1
`Conventions in this Manual ................................................... 3
`Additional RealSystem Resources........................................... 4
`Technical Support................................................................. 4
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`1 WHAT’S NEW IN REALSYSTEM?
`What’s New in Release 7? ...................................................... 7
`RealPlayer 7 New Features ................................................. 7
`RealServer 7 New Features ................................................. 8
`What’s New in RealSystem G2?.............................................. 8
`New Streaming Possibilities ............................................... 9
`Advancements in RealAudio and RealVideo ........................ 9
`Easier Presentation Assembly ............................................10
`Enhanced Protocol Support..............................................11
`Compatibility with Previous Releases.....................................12
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`CREATING REALSYSTEM PRESENTATIONS
`Streaming Multimedia Clips..................................................15
`Choosing Media to Stream ...............................................15
`Clip Types Played by Previous RealPlayer Releases ..............17
`Using Editing and Production Tools ......................................18
`RealNetworks Production Tools ........................................19
`Additional Tools ..............................................................19
`Working with Timelines and Bandwidths ...............................20
`Synchronizing Clips to a Timeline......................................20
`Keeping a Bandwidth Budget ............................................22
`Writing a SMIL File...............................................................22
`Hosting a Presentation on a Server ........................................25
`Using RealServer or a Web Server ......................................25
`Using RealNetworks Logos ...............................................27
`Playing Clips Back Locally .................................................28
`Viewing a Presentation with RealPlayer ..................................28
`Protecting Copyrighted Content........................................28
`Downloading RealPlayer Plug-Ins......................................28
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`31
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`TARGETING BANDWIDTH
`What is Bandwidth?.............................................................31
`What is Preroll? ...............................................................32
`Choosing a Target Bandwidth ..............................................33
`Developing a Bandwidth Strategy..........................................34
`Understanding Clip Bandwidth Characteristics ..................34
`Delivering a Single Media Clip...........................................36
`Developing Multiclip Presentations...................................37
`Supporting Multiple Bandwidth Connections ........................39
`Using SureStream Clips for Multiple Bandwidths ...............39
`Letting RealPlayer Choose between Multiple Clips .............40
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`43
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`PRODUCING AUDIO
`Steps for Streaming RealAudio..............................................43
`Capturing Audio ..................................................................45
`Optimizing Audio ................................................................47
`Creating RealAudio Clips......................................................48
`Choosing RealAudio Codecs.............................................49
`Encoding RealAudio with RealSystem Tools ......................52
`Streaming Other Audio Formats ...........................................53
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`PRODUCING VIDEO
`Steps for Streaming RealVideo ..............................................55
`Recording Video ..................................................................57
`Digitizing Video....................................................................58
`Creating RealVideo Clips ......................................................61
`Choosing RealVideo Codecs .............................................61
`Encoding RealVideo with RealSystem Tools .......................62
`Streaming Other Video Formats............................................65
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`67
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`PRODUCING ANIMATION
`Preparing a Flash Clip ..........................................................67
`Choosing a Target Bandwidth ..........................................68
`Adding RealPlayer 5.0 Compatibility.................................70
`Maximizing Flash Efficiency ..................................................71
`Keeping Shockwave Flash Files Small.................................72
`Minimizing CPU Usage.....................................................73
`Using Interactive Commands ................................................74
`Creating a Flash Clip ............................................................75
`Exporting Shockwave Flash...............................................75
`Tuning Shockwave Flash...................................................76
`Exporting Audio...............................................................76
`Delivering the Flash Presentation ......................................77
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`ASSEMBLING A PRESENTATION WITH SMIL
`Creating a SMIL File .............................................................79
`SMIL General Rules..........................................................80
`Specifying Clip Locations......................................................81
`Linking to Clips on RealServer...........................................82
`Linking to Clips on a Web Server.......................................84
`Linking to Local Clips.......................................................84
`Grouping Clips.....................................................................85
`Playing Clips in Sequence..................................................85
`Playing Clips in Parallel.....................................................85
`Repeating a Clip or Group................................................87
`Combining <seq> and <par> Tags.....................................87
`Specifying Timing .................................................................88
`Setting Begin and End Times.............................................89
`Setting Internal Clip Begin and End Times .........................90
`Setting Durations .............................................................91
`Setting a Fill.....................................................................92
`Clip Timing Example ........................................................92
`Switching Between Alternate Choices ....................................93
`Setting Language Choices .................................................94
`Setting Bandwidth Choices ...............................................94
`Adding Presentation Information ..........................................95
`Managing the Playlist .......................................................96
`Using Coded Characters...................................................98
`Laying Out Multiple Clips .....................................................99
`Defining the Layout........................................................100
`Assigning Clips to Regions..............................................107
`SMIL Layout Example .....................................................107
`Linking to Other Media ......................................................108
`Making a Source Clip a Link............................................109
`Targeting RealPlayer or a Browser ...................................109
`Defining Hot Spot Links .................................................110
`Linking to a SMIL File .....................................................113
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`117
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`EXTENDING SMIL
`Defining Image Options......................................................117
`Setting Image Bit Rates...................................................118
`Overriding GIF Transparency ..........................................119
`Linking to a Web Page or Clip .........................................119
`Controlling RealPlayer....................................................119
`Ensuring Reliable Image Transmission .............................120
`Popping Up New RealPlayer Windows.................................121
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`Creating a Link for a New Window..................................121
`Examples of Opening New RealPlayer Windows...............123
`Caching Images Files ..........................................................125
`Using the “CHTTP” Caching Protocol .............................126
`Controlling the RealPlayer 7 Cache .................................126
`Authoring SMIL Files for Caching....................................128
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`129
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`PLAYING CLIPS IN A WEB PAGE
`Choosing the Netscape Plug-in or ActiveX Control ...............129
`Using <EMBED> Tags for the Netscape Plug-In ...............130
`Using <OBJECT> Tags for the ActiveX Control.................131
`Setting Basic Parameters ....................................................131
`Adding RealPlayer Controls ...............................................133
`Basic Controls ...............................................................134
`Individual Controls and Sliders .......................................135
`Information Panels.........................................................138
`Status Panels .................................................................138
`Linking Multiple Controls...............................................139
`Controlling Image Display ..................................................142
`Setting Automatic Playback ................................................143
`Laying out SMIL Presentations ............................................145
`Defining the Layout with SMIL ........................................145
`Defining the Layout with HTML ......................................145
`Parameter Reference ..........................................................148
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`149
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`INSERTING ADS IN A PRESENTATION
`How Ad Streaming Works ..................................................149
`Displaying Banner Ads .......................................................150
`Laying Out the Banner Region ........................................150
`Setting Banner Ad Properties ..........................................152
`Interleaving Media Ads with Clips .......................................153
`Creating a SMIL File for a Media Ad................................153
`Disabling the RealPlayer Playlist......................................154
`Playing Interstitial Ads....................................................155
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`DELIVERING A PRESENTATION
`Using RTSP and HTTP in URLs ...........................................157
`Streaming Clips from RealServer .........................................158
`Linking your Web Page to RealServer...............................159
`Using Ramgen ...............................................................160
`Playing Clips from a Web Server..........................................161
`Limitations on Web Server Playback................................163
`Configuring Web Server MIME Types ..............................165
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`A
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`B
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`C
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`Creating a Ram File Manually .............................................165
`Changing a Presentation’s Starting Size ...........................167
`Adding Comments to a Ram File.....................................169
`Testing your Presentation ...................................................169
`Advertising on RealGuide....................................................170
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`171
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`BROADCASTING A PRESENTATION
`Broadcasting vs. On-demand Delivery .................................171
`Broadcasting Tools ........................................................172
`Preparing a Broadcast ........................................................174
`Using SMIL with a Broadcast ..............................................176
`SMIL Limitations for Broadcasts .....................................176
`Including On-Demand Clips with Broadcasts...................176
`Synchronizing Multiple Broadcast Streams ......................177
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`QUICK ANSWERS TO COMMON QUESTIONS
`Creating Streaming Clips ....................................................179
`Getting Production Tools ...................................................180
`Using SureStream...............................................................181
`Writing SMIL Files ..............................................................182
`Streaming Clips..................................................................183
`Advertising.........................................................................185
`Broadcasting .....................................................................185
`Getting Technical Support ..................................................187
`
`QUICK STEPS FOR STREAMING CLIPS
`Streaming a RealAudio or RealVideo Clip ............................189
`Embedding a RealVideo Clip in a Web Page.........................191
`URL Reference ...................................................................192
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`195
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`ADVANCED PRODUCTION TECHNIQUES
`Viewing SMIL Source Mark-Up............................................195
`Smoothing Transitions between Clips..................................195
`Hiding Regions with z-index ................................................197
`Writing Complex SMIL Switch Statements ...........................199
`Switching with SureStream Clips .....................................199
`Switching with Multiple Test Attributes ...........................199
`Switching Presentations for Different RealPlayer Versions .201
`Displaying Captions for the Hearing Impaired......................204
`Filling a Captions Region when Captions are Off .............205
`Resizing the Playback Area for Captions ..........................205
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`D
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`SMIL QUICK REFERENCE
`Header Tags ......................................................................207
`<meta.../> .....................................................................207
`<layout>...</layout> ......................................................208
`Clip Source Tags ................................................................209
`Image Source Tag Options .............................................211
`Group Tags .......................................................................212
`<par>...</par>...............................................................212
`<seq>...</seq>...............................................................213
`<switch>...</switch>......................................................214
`Hyperlink Tags ...................................................................215
`<a>...</a> .....................................................................215
`<anchor.../> ..................................................................215
`Pop-Up Window Commands..........................................216
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`E
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`F
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`FILE TYPE REFERENCE
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`SMIL LANGUAGE CODES
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`GLOSSARY
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`INDEX
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`INTRODUCTION
`
`Welcome to RealSystem, the most sophisticated system for
`streaming multimedia files across a network. This manual will help
`you produce your multimedia presentation, whether you simply
`want to stream a video from your home page or create a multimedia
`extravaganza with video, audio, animation, images, and text.
`
`Note
`The HTML version of this manual, available at
`http://service.real.com/help/library/encoders.html,
`contains multimedia examples you can view with
`RealPlayer.
`
`How this Manual is Organized
`This manual tells how to assemble a RealSystem presentation. Although it
`gives tips on producing great content, the more you know about producing
`audio, video, and graphics in general, the faster you’ll put together a great
`streaming presentation. If you know the basics of HTML, you’ll find it easy to
`pick up SMIL, the language used to assemble RealSystem presentations.
`
`Additional Information
`This manual does not explain how to use RealSystem
`tools like RealProducer. For specific information about
`running a tool, refer to the tool’s manual or online help.
`
`Chapter 1: What’s New in RealSystem?
`If you’re familiar with previous versions of RealSystem, this chapter will give
`you a quick update on the many changes in this version of RealSystem.
`
`Chapter 2: Creating RealSystem Presentations
`If you are new to streaming media, this chapter walks you through the steps
`you take to put together a RealSystem presentation.
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` Introduction
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`RealSystem G2 Production Guide
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`Chapter 3: Targeting Bandwidth
`This chapter explains how to target bandwidth connections, an important
`step for creating a streaming media presentation.
`
`Chapter 4: Producing Audio
`This chapter gives you pointers on capturing and digitizing high-quality
`audio. It then gives you the background you need to encode a RealAudio file.
`
`Chapter 5: Producing Video
`Read this chapter to learn how to capture high-quality video and optimize it
`for conversion to RealVideo.
`
`Chapter 6: Producing Animation
`Macromedia’s Flash animation paired with a RealAudio soundtrack produces
`dazzling animated presentations. This chapter tells you how to create Flash
`content for streaming with RealSystem.
`
`Chapter 7: Assembling a Presentation with SMIL
`After you create your multimedia clips, you write a SMIL file that pulls the
`presentation together. This chapter explains how to use SMIL to specify when
`and how each part of your presentation plays.
`
`Chapter 8: Extending SMIL
`RealNetworks has developed several extensions to SMIL that enhance its
`media streaming capabilities. This chapter explains these extensions, which
`work only with RealServer and RealPlayer.
`
`Chapter 9: Playing Clips in a Web Page
`If you want to integrate your presentation seamlessly into your Web page,
`follow the instructions in this chapter.
`
`Chapter 10: Inserting Ads in a Presentation
`This chapter explains how to use SMIL to insert ads into your streaming
`presentation.
`
`Chapter 11: Delivering a Presentation
`This chapter provides step-by-step instructions for moving your presentation
`files to RealServer and linking your Web page to them. It also explains how to
`use a Web server to deliver simple presentations.
`
`Chapter 12: Broadcasting a Presentation
`Refer to this chapter if you plan to broadcast an audio or video event.
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`RealSystem G2 Production Guide
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` Introduction
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`Appendix A: Quick Answers to Common Questions
`If you are new to RealSystem, this appendix answers basic production
`questions and points you to additional resources on the Internet.
`
`Appendix B: Quick Steps for Streaming Clips
`This appendix lists the basic steps you take to get a clip to stream from
`RealServer or a Web server.
`
`Appendix C: Advanced Production Techniques
`For advanced users, this appendix conveys useful production techniques that
`help you get the most out of RealSystem.
`
`Appendix D: SMIL Quick Reference
`Once you understand SMIL as described in Chapter 7, use Appendix D as a
`reference when writing SMIL files.
`
`Appendix E: File Type Reference
`This appendix provides a quick reference for common file types used in
`RealSystem streaming.
`
`Appendix F: SMIL Language Codes
`If you create clips in different languages, you can use these codes in the SMIL
`file to indicate language choices.
`
`Conventions in this Manual
`The following table explains the conventions used in this manual.
`
`Convention
`variables
`
`Notational Conventions
`Meaning
`Italicized text represents variables. Substitute values
`appropriate for your situation.
`Bolded text is used for emphasis.
`Square brackets indicate optional values you may or may
`not need to use.
`choice 1|choice 2 Vertical lines separate values you can choose between.
`...
`Ellipses indicate nonessential information omitted from
`the example.
`
`emphasis
`[options]
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` Introduction
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`RealSystem G2 Production Guide
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`Additional RealSystem Resources
`In addition to this manual, you may need the following RealNetworks
`resources, available at http://service.real.com/help/library/index.html:
`
`• RealText Authoring Guide
`This manual explains how to create streaming text. You can use RealText,
`for example, to create a stock ticker or provide video subtitles.
`
`• RealPix Authoring Guide
`With RealPix you can create streaming slideshows of still images. RealPix
`Authoring Guide explains how to put a RealPix presentation together with
`special effects such as fades and zooms.
`
`• RealServer Administration Guide
`The basic reference for the RealServer administrator, this manual explains
`how to set up, configure, and run RealServer to stream multimedia. You
`need this manual only if you are running RealServer yourself.
`
`• Embedded RealPlayer Extended Functionality Guide
`This guide supplements RealSystem Production Guide. It explains how to use
`JavaScript or VBScript to control RealPlayer functions for a presentation
`embedded in a Web page.
`
`• RealSystem Authoring Kit
`The Authoring Kit contains production tools, utilities, and manuals in a
`single, convenient bundle. It is available through registration at
`http://www.realnetworks.com/products/authkit/index.html.
`
`• RealSystem Software Development Kit (SDK)
`The RealSystem SDK lets you integrate applications with RealSystem or
`create new plug-ins for RealServer or RealPlayer. Knowledge of
`programming is required to use the SDK. Register for and download the
`SDK from http://www.realnetworks.com/devzone/.
`
`Technical Support
`For technical support with RealSystem, please fill out the form at:
`
`• http://customerrelations.real.com/scripts/rnforms
`/contact_tech_service.asp
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` Introduction
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`The information you provide in this form will help technical support
`personnel to give you a prompt response. For general information about
`RealNetworks' technical support, visit:
`
`• http://service.real.com/help/call.html
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` Chapter 1: WHAT’S NEW IN REALSYSTEM?
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`The open, end-to-end architecture of RealSystem changes the nature
`of streaming multimedia, giving you more possibilities for creating
`Web-based multimedia than before. If you’re familiar with past
`versions of RealSystem, this chapter gives you a quick look at the
`many changes in the latest releases of RealSystem.
`
`What’s New in Release 7?
`Release 7 is based on RealSystem G2 technology. It has all the capabilities of
`RealSystem G2, and introduces new features for RealServer 7, RealPlayer 7, and
`RealProducer 7. The following sections describe the new Release 7 features
`that affect content authoring.
`
`RealPlayer 7 New Features
`
`The following features may affect how you produce streaming media for
`RealPlayer 7. See the RealPlayer 7 online help for information about changes
`to the RealPlayer 7 user interface.
`
`PNG Images Supported
`RealPlayer 7 includes support for the Portable Network Graphics (PNG) image
`format (.png file extension) in addition to JPEG and GIF formats. You can now
`use PNG images in both SMIL and RealPix presentations.
`
`Pop Up Multiple RealPlayer 7 Windows
`You can write hyperlinks that open content in new RealPlayer 7 windows. This
`lets you pop up a new RealPlayer window when a viewer clicks a link in a SMIL
`or RealText presentation.
`
`Additional Information
`See “Popping Up New RealPlayer Windows” on page
`121.
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`CHAPTER 1: What’s New in RealSystem?
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`RealSystem G2 Production Guide
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`Cache Graphics with RealPlayer 7
`You can instruct RealPlayer 7 to cache image files downloaded through HTTP.
`This is useful for SMIL presentations that RealPlayer 7 users repeatedly view.
`On reloads or revisits, RealPlayer uses cached images instead of downloading
`the images again from the server.
`
`Additional Information
`See “Caching Images Files” on page 125.
`
`View SMIL Source Mark-Up for Streamed Presentations
`RealPlayer 7 has a View>Source command that displays the mark-up for the
`presentation’s SMIL source file in your Web browser. This helps you learn how
`other content authors have assembled their presentations.
`
`Additional Information
`See “Viewing SMIL Source Mark-Up” on page 195.
`
`RealServer 7 New Features
`See RealServer Administration Guide for full information about new features in
`RealServer 7. The following RealServer 7 features may affect how you produce
`streaming media presentations.
`
`Ad Streaming
`RealServer 7 has an advertising extension that lets you display banner ads in
`RealPlayer during streaming presentations. You can also stream media ads in
`formats such as RealVideo and Flash. This feature works with all major ad
`serving systems. The RealServer administrator configures most features of ad
`streaming.
`
`Additional Information
`For information on creating SMIL presentations that
`include ads, see Chapter 10 beginning on page 149.
`
`What’s New in RealSystem G2?
`RealSystem G2, introduced in 1998, is a complete streaming media platform
`based on a new software architecture. Fundamentally different from previous
`versions of RealSystem, such as RealSystem 5, it uses an open architecture that
`allows software developers to add new features to RealPlayer and RealServer by
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`CHAPTER 1: What’s New in RealSystem?
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`developing plug-ins. It is also the first streaming media system built to use a
`standards-based streaming protocol (RTSP) and timing language (SMIL).
`
`New Streaming Possibilities
`
`Text and Still Images Now Stream
`RealText and RealPix let you stream text and create streaming slideshows that
`use special effects such as fades and zooms. In RealSystem G2, they join
`RealAudio, RealVideo, and Flash as standard RealSystem clip types. In
`addition, RealPlayer G2 and RealPlayer Plus G2 can display JPEG and GIF
`images.
`
`Additional Information
`See “Choosing Media to Stream” on page 15.
`
`Popular File Formats Stream Natively
`With RealSystem, you can now stream many popular audio and video formats.
`Stream WAV files without conversion to RealAudio, for example, AVI without
`conversion to RealVideo. Note, however, that these file formats typically do
`not stream over networks as easily and robustly as RealAudio and RealVideo.
`
`Additional Information
`See “Choosing Media to Stream” on page 15.
`
`Open Plug-In Architecture Streams New File Types
`RealSystem’s open architecture lets RealNetworks’ development partners
`create plug-ins to stream virtually any file type. Automatic download of plug-
`ins ensures that RealPlayer users can play new RealSystem streaming file types
`as soon as they are introduced.
`
`Additional Information
`For more on the RealNetworks developer program, visit
`http://www.realnetworks.com/devzone/realdevelopers/.
`
`Advancements in RealAudio and RealVideo
`
`SureStream™ Technology Encodes Single Clips for Multiple Bandwidths
`The new SureStream technology available exclusively in RealSystem G2 lets
`you encode a single RealAudio or RealVideo clip for up to six separate
`bandwidths. All Web page visitors click the same link to play the clip, but their
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`CHAPTER 1: What’s New in RealSystem?
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`RealSystem G2 Production Guide
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`RealPlayers receive different encodings appropriate for their various
`connection speeds.
`
`Additional Information
`See “Using SureStream Clips for Multiple Bandwidths”
`on page 39 for an overview of SureStream.
`
`New RealAudio Codecs Provide Superior Sound Quality
`RealSystem G2 introduces a new family of RealAudio codecs that provides fast
`encoding, superior sound, and the ability to encode a single clip for delivery at
`different bit rates using SureStream technology.
`
`Additional Information
`“Choosing RealAudio Codecs” on page 49 lists the new
`codecs.
`
`New RealVideo Codec Provides Fast Encoding for Multiple Bandwidth Clips
`RealSystem G2 introduces a new RealVideo codec that provides faster
`encoding and lets you use SureStream technology to encode a single
`RealVideo clip for up to six different bandwidths.
`
`Additional Information
`See “Choosing RealVideo Codecs” on page 61 for more
`information.
`
`Easier Presentation Assembly
`
`SMIL Files Coordinate Presentations
`For presentations that include more than one clip, you create a SMIL file to
`specify how and when each clip plays. SMIL, which stands for Synchronized
`Multimedia Integration Language, is a standardized language that uses a
`simple mark-up similar to HTML to coordinate a streaming presentation.
`
`Additional Information
`For a look at SMIL features, see “Writing a SMIL File”
`on page 22. Refer to Chapter 7 beginning on page 79 for
`instructions on using SMIL.
`
`Bandwidth Negotiation through Multiply-Encoded Clips or SMIL
`RealSystem G2 introduces simpler methods for supporting multiple
`bandwidth connections. As described previously, the new SureStream
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`CHAPTER 1: What’s New in RealSystem?
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`technology allows you to encode a single RealAudio or RealVideo clip for
`multiple connection speeds. Or you can let RealPlayer choose between
`different versions of a presentation based on bandwidth parameters in the
`SMIL file. Either way, you need just one link on your Web page, and your
`encoded clips do not need to conform to any naming conventions.
`
`Additional Information
`See “Supporting Multiple Bandwidth Connections” on
`page 39 for an overview.
`
`RealPlayer Launched Automatically
`The Ramgen feature of RealServer™ can launch RealPlayer automatically. This
`means you do not need to create a Ram file (extension .ram or .rpm) manually.
`In your Web page, you link to a SMIL file or media clip, including in the URL
`a Ramgen parameter that causes the Web browser to launch RealPlayer and
`give it the SMIL file or clip.
`
`Additional Information
`See “Linking your Web Page to RealServer” on page 159.
`
`Enhanced Protocol Support
`
`RTSP Protocol Now Used
`Because it still supports the PNA protocol, RealServer for RealSystemG2 is
`backwards compatible with RealSystem 3.0 through 5.0. But it introduces as
`its primary protocol the RealTime Streaming Protocol (RTSP), an open,
`standards-based protocol for multimedia streaming. Because of this, URLs
`that point to media clips on RealServer now begin with rtsp://.
`
`RealSystem Interoperates with RTP-Based Servers and Clients
`When communicating with RealPlayer, RealServer uses RealTime Streaming
`Protocol (RTSP) as its control protocol and RealNetworks’ proprietary RDT as
`its packet protocol. But because RealSystem G2 also supports international
`standards for streaming media, RealServer and RealPlayer interoperate with
`
`11
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`BTN0004142
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`19
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`

`CHAPTER 1: What’s New in RealSystem?
`
`RealSystem G2 Production Guide
`
`RTP-based media servers and clients. The following table lists the protocols
`used with different mixes of servers and clients.
`
`RealSystem Protocols
`
`Control
`Protocol
`Client
`Server
`RealServer G2 and higher RealPlayer G2 and higher RTSP
`RealServer G2 and higher RTP-based client
`RTSP
`RTP-based server
`RealPlayer G2 and higher RTSP
`RealServer G2 and higher RealPlayer 3.0 to 5.0
`PNA
`RealServer 3.0 to 5.0
`RealPlayer G2 and higher PNA
`
`Packet
`Protocol
`RDT
`RTP
`RTP
`PNA
`PNA
`
`Compatibility with Previous Releases
`RealSystem 7 and Re