About QuickTime Streaming

Streaming is a technology that lets you view multimedia as it arrives at your computer. With streaming, your users can tune in to broadcasts of live or prerecorded media, or they can view prerecorded media on demand. Users see streamed media as soon as it reaches the computer; they don't have to wait to download files.

Media streams are sent from a server to a client computer in one of several ways: unicast, multicast, reflected unicast, or reflected multicast. Unicast is a one-to-one transmission. Each client computer that tunes in to a stream receives its own stream. A multicast stream is sent to a group address. This means several client computers can tune in to the same stream.

QuickTime movie can be streamed only if it has been hinted. Hinting involves using software that analyzes the media data within a movie and creates hint tracks which tell the streaming server software how to package the data to send over the network. You can hint movies using the Pro version of QuickTime Player. When you hint a movie, QuickTime Player creates one hint track for each media track in the movie. The hint tracks are stored within the movie, and the movie becomes a hinted QuickTime movie.

(Note: all these examples of live video can be archived and stored on a streaming server to be accessed at any time by your audience.)

• Meetings
  (Do you have meetings where you present information to an audience that has to travel to your location? How about broadcasting your presentation or meeting so some of your audience can attend by viewing it over the Web?)
• Satellite Broadcasts
  (instead of inviting people to a county of district office to observe a satellite broadcast , you can stream it live over the Internet.)
• Daily, Weekly or Monthly Addresses
  by Superintendent, Principal, Student Body President, etc
• Keynotes/Conference Presentations
• School Sporting Events (You will more then likely need a wireless set up for this)
• Student Reports/Presentations from the Classroom
  (Parents can view over the Internet)
• Graduations and other Ceremonies
• Musical Events or School Plays
• Technical Tips of the Week

Environmental Science Projects: "Through the eyes and ears of Sorenson Broadcaster, for 24 hours every day, we bring an ecologically sensitive marine ecosystem to the Internet," said Garry Fletcher, Educational Director of the RaceRocks.com Project. Three cameras broadcast from the Race Rocks Ecological Reserve 24 hours a day. http://www.racerocks.com/

Archived:
Rancho Bernardo High School's Digital Media Production class in SanDiego has begun to produce a weekly Webcast of school events and highlights. Visit http://powayusd.sdcoe.k12.ca.us/pusdrbhs/ and click on the current or previous issues of the Bronco Magazine. ( you will need a current copy of Quicktime Player 5 on your computer to view the video...you can download quicktime for windows or macintosh at www.apple.com/quicktime

Archived Educational Video (science, Social Studies, Health, etc)
An example of a (subscription) company that is using MS Media Player streaming video to deliver educational videos is: http://www.unitedstreaming.com/

A company that will store and stream your content for you. Sorenson VCAST.
Visit them at http://vcast.sorenson.com/

Equipment Needed:

Video Source (Digital/Analog)--Digital Camera, VCR, TV, etc Power Macintosh G3 (or better) Workstation or Powerbook (loaded with sorenson broadcaster) Computer will need USB, Firewire or digital video card,...one option for bringing video in via USB is: Interview 2.0 (USB) It allows any PowerMac user (users without native USB ports will need the USB/PCI version) to plug into full media capture in minutes. http://www.xlr8.com/ProductInfo/interview/ Power Macintosh G3 or G4 (used as replication or relay server if needed) (loaded with OSX & QT Streaming Server)

Software Needed:

Sorenson Broadcaster - http://www.sorenson.com FTP client - http://www.shareware.com Quicktime Player Pro - http://www.apple.com/quicktime/download/ Optional:OSX Server - http://www.apple.com/macosx/

Step by Step Directions to Stream a Live Broadcast with Broadcaster (No Relay or Replication Server):

Workstation or Powerbook:

Plug Video source into Computer (with A/V, Firewire or USB Capabilities)
Turn Video Source On
Launch Sorenson Broadcaster(With Virtual Memory Off)

Click on Quality TAB

• Choose Target Audience DATA Rate by clicking on Target Audience button (example: if your target audience is all on modems choose 28.8 if they are on a WAN that is connected with T1's connect a much higher rate)
• Audio checked with emphasize voice checked
• Video Checked and then check the appropriate motion speed for your broadcast

Click on sources TAB:

• Click on Video Source Button to select video source that sincs up with your input source (once you select the correct source you should see your video appear on screen)
• Click on Audio Source Button to select audio source that sincs up with your input source

Click on Publishing TAB:

• The information here is optional but gives your audience information including copyright warning.

Click on Network TAB:

• Click on Broadcast Type pull down menu and select "Multicast" for our example.

Click on Recording TAB:

• We will not be demonstrating this tab as its purpose is to save your live broadcast as a file to be played back later or archived.
• Now you are ready to export your announcement (to let people now how to get to your broadcast)

Click on ANNOUNCE BUTTON at top right of sorenson window.

• Export Announcement dialogue box appears.
• From the format drop down menu select announcement movie and name the movie with the .mov suffix (.sdp text announcement is used if you will be using a relay or replication server (OSX)). You will have to FTP this file so perhaps save to your desktop.....then click save. This .mov file is just a pointer and not the actual broadcast.
• Now you can email this .mov file to users on your network or embed it in a web page so people just click on a link to get the broadcast stream. We will use an FTP client to ftp this .mov file to a web server where we will embed it into a web page.

• (We are using FETCH 3.03 for Mac OS). Fill in host field with the domain name or IP address of your web server.
• Fill in the User ID field with your user ID
• Fill in the Password field with your FTP password
• ftp the .mov file to your web folder and create a web page that has a link that references this .mov file

1. Switch back to Sorenson Broadcaster window which is still open and press the BROADCAST button upper left hand corner.
2. If you emailed your users copies of the .mov file they can just double click it and quicktime player will launch and connect to your broadcasting machine to view the broadcast through the quicktime player. (make sure you users have the most recent versionof QT on their computer).
3. If you embeded the .mov in a web page, just give your users the web address of the page and have them click on the link.

You can set up network broadcasts several different ways using Sorenson Broadcaster. The most common scenarios are:

No server required:

• Multicasting--sends the stream from Sorenson Broadcaster to unlimited recipients on your network.

  Why would you Multicast? To send a stream to multiple users on a local network. 

• Unicasting to a single recipient--sends the broadcast directly from Sorenson Broadcaster to a single recipient.

  Why would you Unicast? To send a stream over the Internet to a single recipient.

Server required:

• Using a replication server--sends the broadcast from Sorenson Broadcaster to replication server(s), such as Mac OS X and then replicates the stream as multiple unicast streams (one stream per recipient) sent to numerous recipients.

  Why would you use a replication server? To send a stream over the Internet to multiple recipients.

• Using a relay server--unicasts the broadcast across the Internet to a relay server on a local network and then relays the stream as a multicast to other recipients on the same network.

  Why would you use a relay server? To send a stream across the Internet to a group of people that reside on a local network.

Sorenson Broadcaster Scenario 1: Multicasting

Multicasting is a method of streaming that sends one stream to which an unlimited number of recipients may "tune in." Multicasting = "stream to many."

The advantage of multicasting is that data is only sent to portions of the network where recipients reside and request the data. Consequently, multicasting optimizes network bandwidth consumption and is more efficient when sending data to multiple users.

The disadvantage of multicasting is that the network you broadcast over must be multicast enabled. LANs and most Intranets are multicast enabled, but because many firewalls and routers do not transmit multicast data, you cannot multicast across much of the Internet.

The following diagram illustrates a Multicast broadcast:

To multicast your stream:

1. Start Sorenson Broadcaster and test your audio and video source devices.
2. In the Quality tab, select the configuration settings for your broadcast.
3. In the Network tab, select Multicast (the default) from the Broadcast Type list.
4. Create an announcement file and distribute it to all the recipients on your network.
5. Click the Broadcast button to start your live stream.
6. View the broadcast by double-clicking the announcement movie.

Sorenson Broadcaster Scenario 2: Unicasting to a single recipient

Multicasting works great for local networks, but what if you want to send data over the Internet? The most reliable method is to use a unicast stream. Unicasting is a method of streaming that sends a new copy of the data for each individual recipient. Unicasting = "stream to one."

The advantage of unicasting is that Internet routers and firewalls transmit unicast streams consistently.

The disadvantage of unicasting is that a unique copy of the data is sent to every recipient, even when multiple users want the same data at the same time. Consequently, unicasting uses more bandwidth than a multicast sending the same data. Also, If you want to unicast to multiple recipients, you must add a server to your system (see scenarios 3 and 4).

The following diagram illustrates Unicasting to a single recipient:

To unicast your broadcast to a single recipient:

1. Start Sorenson Broadcaster and test your audio and video source devices.
2. In the Quality tab, select the configuration settings for your broadcast.
3. In the Network tab, select Unicast from the Broadcast Type list.
4. In the Network Address box, enter the network address of the computer to which you are broadcasting.

   You can enter a standard IP address, or you can use a network name (mycomputer.mycompany.com) if the broadcast recipient is recognized by your name server. If you have questions, consult your network administrator.

5. Create an announcement file and send it to the computer whose network address you specified.
6. Click the Broadcast button to start your live stream.
7. View the broadcast by double-clicking the announcement movie.

Sorenson Broadcaster Scenario 3: Using a replication server

Unicasting (as described previously) works great for sending data across the Internet to a single recipient, but what if you want to send data to multiple recipients? A software application called a "replication server" is the most reliable method for sending data across the Internet to multiple recipients. With a replication server, you multicast or unicast a stream to the server, the server then "replicates" the incoming stream as multiple unicast streams that are distributed to numerous recipients.

Using Broadcaster in conjunction with a replication server, such as Mac OS X Server, is the only reliable method for getting your live stream to multiple viewers over the Internet. (This will change as Internet router software is upgraded to allow multicast streams).

Replication servers are one of the most exciting features of QuickTime 4. Some technologies, such as Real Networks, charge on a per stream basis for their replication servers. Software prices range from $8400 for a 100 stream server, to $30,000 for a 400 stream server (source: Real Networks 5/24/98). These costs are only for the server software, encoding software and hardware are sold separately.

Apple has broken this mold by including their replication server as a standard part of Mac OS X Server and, most importantly, "open-sourcing" the replication server software. This means that anyone can download the source code for the QuickTime 4 replication server, or QuickTime streaming server (QTSS), and use it as a starting point for creating their own server.

QuickTime streaming servers are available from Apple, IBM, SGI, Sun, and Cisco. Expect more to be available soon.

The following diagram illustrates a general configuration for a broadcast using a replication server:

To broadcast using a replication server:

1. Start Sorenson Broadcaster and test your audio and video source devices.
2. In the Quality tab, select the configuration settings for your broadcast.
3. In the Network tab, select Multicast or Unicast from the Broadcast Type list.
   • If the server does not reside on the same local network as the Broadcaster machine, unicasting is the most reliable method for sending the stream to the server.

     If the server and the Broadcaster machine reside on the same network, multicasting is preferred because it allows for scalability (you can scale the number of servers independently of the number of broadcasting stations). For example, if you have too many clients for one server to handle, you can put another server within multicast range.

   • If you select Unicast, enter the network address of the replication server in the Network Address box.
     
   • If you select Multicast, let Broadcaster choose the IP address.
     
4. Create an announcement file with a .sdp extension and save it to a directory where the server can locate it.

   For example, with the Mac OS 10 the default is Local/Library/QTStreaming/Movies.

5. Click the Broadcast button to start your live stream.
6. Start the QuickTime 4 Player Pro.
7. Select the Open URL command from the File menu and open the .sdp file from the replication server.
8. Save the .sdp file as a .mov file. The .mov file is a reference movie that "refers" to your stream so you can distribute it to your intended recipients.

   Note: The preceding three steps are critical to ensure that the reference movie refers to the stream coming from the replication server and not the stream coming from Broadcaster.

9. View the broadcast by double-clicking the reference movie. 

Sorenson Broadcaster Scenario 4: Using a relay server

The replication server works great for sending multiple unicast streams across the Internet, even though it is an inefficient use of bandwidth (due to the "one stream per recipient" limitation). But, what if you want to broadcast across the Internet to a group of people that reside on the same local network and not pay the price for individual streams to each user? With a relay server, you can.

A relay server will accept a unicast stream, from across the Internet, for example, and "relay" it as a multicast stream onto your local network. Thus, by using a relay server, you can send a single stream across the Internet to multiple users. The only constraint is that those users must all reside on the same local network. The following diagram illustrates a broadcast using a relay server:

To broadcast using a relay server: 

1. Start Sorenson Broadcaster and test your audio and video source devices. 
2. In the Quality tab, select the configuration settings for your broadcast.
3. In the Network tab, select Relay from the Broadcast Type list.
4. Enter the IP address of your relay machine in the Network Address box. Choose port numbers that do not cause a conflict between the incoming and outgoing streams.
5. Create an announcement file for the broadcast with a .sdp extension and send it to the correct location on your relay server. 
6. Create a second announcement file with a .mov extension and distribute it to the recipients of your stream. 
7. Click the Broadcast button to start your live stream.
8. View the broadcast by double-clicking the reference movie.

As with any documentation about technology, we use our share of acronyms and jargon. We provide this glossary as a quick reference of terms and concepts that may not be familiar to you. All terms are listed in alphabetical order.

Bandwidth Broadcast Codec Composite Video Data Rate Digitizer Firewall

HTTP IP Address Multicast NTSC PAL Port Progressive Dwnld

RTSP Router S-Video Server Streaming Unicast URL

Bandwidth

The amount of data/second that can be delivered across a connection, such as a cable, interface or bus. A 28.8 modem has a bandwidth of 28.8 Kb/second.

Broadcast

A streaming option that sends a single stream that branches down all channels, regardless of whether a client is listening. In relation to Sorenson Broadcaster, broadcast is generally used to mean "streaming."

Codec

A contraction for the terms Encoder/Decoder. A codec encodes data for efficient transmission and then decodes the received data for presentation.

Composite Video

A video stream that combines all the signals required for displaying video into one signal, thus requiring only one connection. NTSC is an example of composite video.

Compression

The act of making a file or data stream smaller.

Data Rate

A measurement of bandwidth. Higher data rate equals more bandwidth. In general, the higher the data rate, the higher the quality of video and/or audio.

Digitizer

The capture card or device that converts an analog signal into a digital signal. A video digitizer will convert an analog video signal into a digital stream or file.

Firewall

A form of Internet security that stands between a private network and the Internet. A firewall can prevent unwanted traffic from passing through.

HTTP

Hyper Text Transfer Protocol. The standard protocol used to transfer information on the world wide web.

IP Address

The specific network address of a computer on a network using TCP/IP as its network protocol.

Multicast

A single stream of data only sent to the portions of the network where there are users interested in receiving it. Multicasting provides optimum bandwidth efficiency over networks.

NTSC

National Television Standards Committee. The NTSC defines the North American television standard.

PAL

Phase Alternating Line. The dominant European television standard.

Port

Used in TCP/IP to distinguish between different types of communication between TCP/IP addresses. Communication can be established at different ports to keep conversations separate.

Progressive Download

QuickTime supports progressive downloads of movies, which allow part of a movie to be displayed before all of its data has been received over a network or other slow link. QuickTime is able to instantiate the movie and start playing it before the entire file has arrived. This is known as Fast-Start movie playback.

QuickTime

Apple Computer's multimedia delivery architecture.

RTSP

RealTime Streaming Protocol. The standard used to transmit stored media to one or more clients at the same time. Provides client controls for random access to the content stream. Requires an RTSP server. RTSP uses RTP as the transport protocol.

Router

A device that bridges an internal network to another network. Also, a device used to bridge a computer to a long distance digital communications network, such as ISDN.

S-Video

Separate Video, also called Y/C video. The Y/C designation is shorthand for luma (Y) and chroma (C).

Server

A computer whose sole purpose is to supply information in its many forms, so that other computers can use it. For Broadcaster the server of interest is a QuickTime Streaming Server, which accepts streams from Broadcaster and re-transmits them to many clients.

Streaming

Playing a multimedia file as it downloads.

Unicast

Delivering a separate stream for each user. Unicasting is inefficient in bandwidth usage.

URL (Universal Resource Locator)

Used to give Web addresses for HTML, VRML, WAV and other files. It contains the Internet name of the machine containing the data and the path to the file. The address also includes what protocol should be used.

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Step by Step directions for this handout were acquired from http://www.sorenson.com 1/5/2001

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