QuickTime Streaming Server Darwin Streaming Server Administrator's Guide K Apple Computer, Inc. © 2002 Apple Computer, Inc. All rights reserved. The owner or authorized user of a valid copy of QuickTime Streaming Server and Darwin Streaming Server software may reproduce this publication for the purpose of learning to use such software. No part of this publication may be reproduced or transmitted for commercial purposes, such as selling copies of this publication or for providing paidfor support services. The Apple logo is a trademark of Apple Computer, Inc., registered in the U.S. and other countries. Use of the "keyboard" Apple logo (Option-Shift-K) for commercial purposes without the prior written consent of Apple may constitute trademark infringement and unfair competition in violation of federal and state laws. 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UNIX is a registered trademark in the United States and other countries, licensed exclusively through X/Open Company, Ltd. 022-0329/11-20-02 Contents Preface QuickTime Streaming 7 What Is Streaming? 7 About Streaming Servers 7 Live Versus On-Demand Delivery Simple Setup for Live Video 8 How Does Streaming Work? 9 Multicast Versus Unicast 10 Relaying Streamed Media 11 The Total Streaming Solution 11 The QuickTime Suite 12 More About QTSS and DSS 12 For More Information 13 1 Getting Started 15 8 Setup Overview 15 Hardware and Software 16 Client Computer Requirements 16 Server Requirements 17 Live Broadcasting Requirements 17 Setting Up Your Streaming Server 18 Testing Your Setup 19 2 Managing Your Streaming Server 21 User Interface 21 Working With Streaming Server Admin 21 3 Viewing Streaming Status 22 Starting or Stopping Streaming Service 22 Working With Connected Users 22 Changing Server Settings 23 Controlling QuickTime Broadcaster Remotely 23 Working With General Settings 24 Working With Port Settings 25 Working With Log Settings 25 Viewing Error Logs and Access History 26 Media 27 About Instant-On Streaming 27 Preparing Prerecorded Media 27 Preparing Audio 28 Streaming Media Files With Multiple Sources 28 Streaming File Formats Like .avi, .text, and .wav 28 Exporting a QuickTime Movie as a Hinted Movie 29 Improving the Performance of Hinted Movies 30 Session Description Protocol (SDP) Files 30 Streaming Live Media 31 Viewing Streamed Media From a Client Computer 31 Setting Up a Web Page With Streamed Media 32 Creating Links to MP3 Playlists 33 Bandwidth Considerations 33 Playlists 34 Using Playlists to Broadcast Prerecorded Media 34 Working With Playlist Settings 34 Starting and Stopping Playlists 35 Creating a Playlist 35 Changing a Playlist 36 Deleting a Playlist 36 Relays 37 Working With Relay Settings 37 Setting Up Relays 38 Turning a Relay On or Off 39 4 Contents Security 39 Resetting the Streaming Server Admin User Name and Password 39 Controlling Access to Streamed Media 40 Creating an Access File 40 What Clients Need to Access Protected Media 42 Adding User Accounts and Passwords 42 Adding or Deleting Groups 42 Making Changes to the User or Group File 42 Installing SSL 43 Using Automatic Unicast (Announce) With QTSS or DSS on a Separate Computer 43 Executing a Command With sudo 44 Streaming on Port 80 45 Firewalls and Networks With Address Translation 45 Problems 45 Streaming Server Admin Is Not Responding 46 The Server Doesn't Start Up or Quits Unexpectedly 46 The Streaming Server Computer Crashes or Is Restarted 46 Media Files Do Not Stream Properly 46 Streaming Performance Seems Slow 47 Users Can't Connect to Your Broadcast 47 Users See Error Messages While Streaming Media 47 Users Can't See Live Streamed Media 48 You're Having Problems With Playlists 48 Advanced 49 How do I bind the Streaming Server Admin computer to a single IP address if my machine is multihomed? 49 How do I bind QTSS or DSS to a single IP address if my machine is multihomed? 50 How do I kill and restart the QuickTime Streaming Server processes in Mac OS X Server? 51 How do I kill and restart Streaming Server Admin processes in Mac OS X Server? 51 How do I get QTSS to re-read its preferences without killing or restarting the server? 52 How do I configure QTSS to host streams from multiple user media directories? 52 3 Setup Example 55 Streaming Presentations--Live and On Demand 55 Contents 5 Setting It Up 57 Creating a Web Page for Easy Access 65 Shooting the Live Presentation 66 Archiving the Live Presentation 66 Glossary Index 77 69 6 Contents PREFACE QuickTime Streaming The focus of this guide is QuickTime Streaming Server (QTSS) and Darwin Streaming Server (DSS). But before getting into the details of QTSS and DSS, it may be helpful to learn what streaming is all about and to get an overview of the total streaming solution provided by the QuickTime suite of products. What Is Streaming? Streaming delivers media from a server over a network to a client in real time, from modem rates to broadband. No file is ever downloaded to a viewer's hard drive. Media is played by the client software as it is delivered. With QuickTime streaming you can deliver m broadcasts of live events in real time m video on demand m playlist broadcasts of prerecorded content About Streaming Servers If you want to send streams to people over the Internet or a local network, you need a streaming server. Just as you need a web server for web pages, and a mail server for email messages, you need a streaming server to send real-time streams. The streaming server transmits video and audio streams to individuals in response to requests from those individuals using client software such as QuickTime Player. The requests are handled using Real-Time Streaming Protocol (RTSP), a protocol for controlling a stream of real-time multimedia content. The streams are sent using Real-Time Transport Protocol (RTP), a transport protocol used for transmitting real-time multimedia content over networks. A streaming server can create streams from QuickTime movies stored on a disk. It can also send copies of any live streams to which it has access. 7 For small audiences, the same computer can run web server software, mail server software, and streaming server software. For larger audiences, one or more computers typically are dedicated to acting purely as streaming servers. Live Versus On-Demand Delivery Delivery options for real-time streaming media are divided into two categories: live and on demand. You can serve both from QuickTime Streaming Server and from Darwin Streaming Server. Live events, such as concerts, speeches, and lectures, are commonly streamed over the Internet as they happen with the assistance of broadcasting software, such as QuickTime Broadcaster. The broadcasting software encodes a live source, such as video from a camera, in real time and delivers the resulting stream to the server. The server then serves, or "reflects," the live stream to clients. Regardless of when different customers connect to the stream, each sees the same point in the stream at the same time. This live experience can be simulated with recorded content by broadcasting from an archive source such as a tape deck or creating playlists of media on the server. For an on-demand delivery experience, such as a movie or an archived lecture, each customer initiates the stream from the beginning, so no customer ever comes in "late" to the stream. No broadcasting software is required in this case. Simple Setup for Live Video The illustration below shows a setup for streaming live video and audio. (Most video cameras have a built-in microphone.) You can stream audio only using a microphone, mixer, and other appropriate audio equipment. Broadcaster Streaming server 8 Preface A PowerBook G4 with QuickTime Broadcaster software captures and encodes video and audio. The encoded signal is sent over an Internet Protocol (IP) network to a server computer running QTSS or DSS software. QTSS or DSS on the server computer sends the signal over the Internet or a local network to client computers that tune in using QuickTime Player. You can also run QuickTime Broadcaster and QTSS or DSS on the same computer. If you are broadcasting to a large audience (more than, say, 100), however, Apple recommends that you run QuickTime Broadcaster and QTSS or DSS on separate computers. How Does Streaming Work? When you watch and listen to cable or over-the-air media transmissions on television or radio, the cable or electromagnetic wavelengths used are dedicated to that transmission. Those transmissions are mostly uncompressed and so consume large amounts of transmission bandwidth. But that's not a problem, because they don't have to compete with other transmissions within the frequency over which they're broadcast. When you send that same media over the Internet, the bandwidth used is no longer dedicated to only that transmission stream. The media now has to share extremely limited bandwidth with thousands, potentially millions, of other transmissions traveling back and forth over the Internet. Multimedia sent over the Internet is therefore encoded and compressed for transmission. The resulting files are saved in a specific location, and streaming server software such as QuickTime Streaming Server or Darwin Streaming Server is used to send the media over the Internet to client computers. Streamed media can be viewed by both Macintosh and Windows users using QuickTime Player (available free on the Apple web site) or any other application that supports QuickTime or standard MPEG-4 files. Streams can also be set up so that users can view them from within a web browser when the QuickTime plug-in is installed. When a user starts to play streamed media through a web page, the QuickTime plug-in sends a request to the streaming server. The server responds by sending the multimedia content to the client computer. The type of multimedia that is sent to the client computer depends on what content you specified on the web page. If you linked to a playlist created on the streaming server, that's sent. If you linked to a QuickTime movie in the specified media directory, that movie is sent. If you linked to a live broadcast, that's sent. QuickTime Streaming 9 Multicast Versus Unicast QTSS and DSS support both multicast and unicast network transport to deliver streaming media. In a multicast, a single stream is shared among the clients (see illustration). Each client "tunes in" to the stream much as a radio tunes in to an FM broadcast. Although this technique reduces network congestion, it does require a network that either has access to the multicast backbone, otherwise called the Mbone, for content generally distributed over the Internet, or is multicast enabled for content distributed within a contained private network. Multicast In a unicast, each client initiates its own stream, resulting in the generation of many one-toone connections between client and server (see illustration). Many clients connected via unicast to a stream in a local network can result in heavy network traffic. But this technique is the most reliable for delivery over the Internet since no special transport support is required. Unicast 10 Preface Relaying Streamed Media QuickTime Streaming Server or Darwin Streaming Server can be configured as a relay. A relay listens to an incoming stream and then forwards that stream to one or more destinations. A relay can reduce Internet bandwidth consumption. Relays can be useful in special broadcast situations, especially if numerous viewers in different locations want to tune in. Large organizations can often make good use of relays. For example, if a company regularly broadcasts a quarterly presentation from the CEO, that broadcast can be relayed from headquarters to branch offices. Broadcaster Destination Clients Internet Relay Destination Company headquarters Branch offices Clients The CEO's presentation is captured live with a video camera. The audio and video from the camera are encoded using QuickTime Broadcaster on a Mac OS X computer. A Mac OS X Server computer with QuickTime Streaming Server software acts as the relay computer and relays the broadcast of the CEO's presentation over the Internet to destination computers serving the company's branch offices. Employees of the ...