hands-on guide to webcasting: internet event and av production (hands-on guide series)

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Library of Congress Cataloging-in-Publication Data

Mack, Steve.

Hands-on guide to webcasting : Internet event and AV production / Steve

Mack.

p. cm. -- (The Focal hands-on guide series)

Includes index.

ISBN 0-240-80754-5 (pbk. : alk. paper) 1. Webcasting. 2. Video

recordings--Production and direction. I. Title: Guide to webcasting. II.

Title. III. Series.

TK5105.887.M328 2006

006.7’876--dc22

2005028126

British Library Cataloguing-in-Publication DataA catalogue record for this book is available from the British Library.

ISBN-13: 978-0-240-80754-6ISBN-10: 0-240-80754-5

For information on all Focal Press publications visit our website at www.books.elsevier.com.

06 07 08 09 10 10 9 8 7 6 5 4 3 2 1

Printed in the United States of America

This Page Intentionally Left Blank

Raw Audio/Video Encoders Servers Network Players

Make sure “BeginBroadcasting …” ischecked

Click on one of thesebuttons to copy the URLfor your webcast.

When players connect to yourwebcast, they are listed in the DirectConnections section.

The URLS are alsodisplayed here.

1

3

2

4

Internet

Disc Drive

a. Downloaded files are reassembled, then displayed.

2341

3

2

4

b. Streaming files are played back as they arrive and then discarded.

PlayerRaw Audio/Video Encoders Servers

StorageCamera/Microphone

Encoders

Master Servers

Public Server

Public Server

Public Server

Public Server

Test Player

Original electrical signal

Each box represents one digital “sample”

+

0

–

44,100 samples * 16 bits/sample * 2 channels = 1,411,200 bits per second = 1,378 Kbps

300Kbps * 100 = 30000Kbps

30000kbps / 1024 = 29.3Mbps

35Mbps * 60 seconds/minute * 60 minutes/hour = 126000Megabits

126000Megabits = 15750 Megabytes / 1024 = 15.38 Gigabytes

Stage

Camera 2riser

Camera 1riser

EncodingA/V ProductionCamera 3

riser

Audio Technica AT803b(omnidirectional lavaliere mic)

Shure SM58®(directional handheld mic)

Key frames are encoded at the beginning of new scenes, orwhen there has been a signifi-cant amount of change in the frame

Difference frames are used to encodeincremental changes between frames

Audio Feed Video Feed

Mixing Desk

Compressor

WM broadband

WM Dialup

Spare

Real broadband

Real Dialup

Spare Switch/Router

VideoSwitcher

Encoding Machines

AmbientMics

VideoProc Amp

Audio/Video DistributionAmplifier

BroadcastOperations

Center

30 fps

20 fps

15 fps

10 fps

...

...

...

...X X X X X XX X X X

X X XX

Interlaced video divides a frame into two fields, sampling (anddisplaying) the odd lines first, and the even lines second.

Progressive video does not have fields. A frame of video is sampled and displayed by starting in the top leftcorner and rendering all the linesprogressively.

Be sure to cropthe rest of yourscreen tomaintain youraspect ratio!

If you want to crop out somenoise, for instance along the bottom ofyour screen…

You can preview different streams by choosing themfrom the Preview drop-down menu.

You can monitor server connection(s) and see what the local link to the stream is on the Connections tab..

You can monitor the encodingmachine statisticsin the systemarea.

… you may need tode-select the“Maintain aspect ratio” setting.

If you’regoing toresize yourvideo…

4

Web Server

StreamingServer

1

2

3

5

1. User clicks on link, issuing a request to a web server.2. Web server returns a metafile.3. Browser identifies metafile as belonging to a streaming media player, and hands it

off to a streaming media application.4. The player opens the metafile, extracts the URL, and issues a request to a streaming server.5. The streaming server sends the stream to the player.

<?xml version=”1.0”>

<?quicktime type=”application/x-quicktime-media-link”?>

<embed src=“rtsp://your.qtserver.com/YourStream.mov” />

<?xml version=”1.0”>

<?quicktime type=”application/x-quicktime-media-link”?>

<embed src=“rtsp://your.qtserver.com/keynote” />

<embed src=“rtsp://your.qtserver.com/keynote” autoplay=“true” fullscreen=“true”

/>

.qtl = application/x-quicktimeplayer

<!– code for Image Window -->

<object classid=”clsid:CFCDAA03-8BE4-11cf-B84B-0020AFBBCCFA”

width=”240” height=”180”>

<param NAME=”controls” VALUE=”ImageWindow” />

<param NAME=”console” VALUE=”one” />

<embed src=”2005Conference.rpm” width=”240”

height=”180” controls=”ImageWindow” console=”one” />

</object>



<object classid=”clsid:CFCDAA03-8BE4-11cf-B84B-0020AFBBCCFA”

width=”375” height=”100”>

<param NAME=”controls” VALUE=”All”/>

<param NAME=”console” VALUE=”one”/>

<param NAME=”src” VALUE=”2005Conference.rpm”/>

<embed src=”2005Conference.rpm” width=”375”

height=”100” controls=”All” console=”one” />

</object>

Audio/Video Encoders Intake Servers Public Servers Load Balancer

Unicast Multicast

Unicast delivery deliversa unique copy of the stream to each player.

Multicast delivery broad-casts a single stream ona controlled network.Each player grabs a local copy.

Click the greenarrow to addstreaming mediaservices.

Click the greenarrow to create apublishing point

100%

80%

60%

40%

20%

0%

41.2%

10.7%

24.0%

7.8%

9.1%

7.1%

Under $50M $50M–$250M $250M–$1B $1B–$5B Over $5B

36.2%

13.8%

22.3%

9.6%

7.4%

10.6%

40.8%

11.3%

16.9%

14.1%

5.6%

11.3%

29.5%

16.4%

31.1%

9.8%

9.8%

32.9%

8.2%

24.7%

11.0%

15.1%

8.2%

Once a month

Once a day More than once a day2-to-3 times a week

2-to-3 times a month Once a week

Source: Aberdeen Group, January 2004

3.3%

Once a month7.9%

2-to-3 times amonth8.8%

Once a week9.2%


More thanonce a day

38.2%

2-to-3 timesa week23.8%

Once a day12.1%

Suppliers Business Users Personal Users Consultants &Analysts

Other

Less than 5 min 5-to-15 min 5-to-30 min 30 min to 1 hour 1-to-2 hours More than 2 hours


100%

80%

60%

40%

20%

0%

9.6% 5.5% 8.9% 10.6% 10.3%

7.7%

16.2%

12.8%

35.0%

17.9%

11.7%

14.9%

18.1%

30.9%

13.8%

11.9%

14.8%

17.8%

25.2%

21.5%

9.3%

20.8%

20.8%

27.3%

16.4%

11.4%

14.0%

14.0%

32.0%

19.1%

1-to-2 hours10.6%

More than2 hours8.8%


5-to-15 min30.3%

15-to-30 min16.2%

30 min to1 hour15.8%

Less than5 min18.2%

100%

80%

60%

40%

20%

0%Suppliers

Less than 5 min 5-to-15 min 15-to-30 min 30 min to 1 hour 1-to-2 hours More than 2 hours

Business Users Personal Users Consultants &Analysts

Other


9.6%

11.4%

14.0%

14.0%

32.0%

19.1% 16.4%

27.3%

20.8%

20.8%

9.3%5.5% 8.9% 10.6% 10.3%

7.7%

16.2%

12.8%

35.0%

17.9%

11.7%

14.9%

18.1%

30.9%

13.8%

11.9%

14.8%

17.8%

25.2%

21.5%

100%

80%

60%

40%

20%

0%Under $50M $50M–$250M $250M–$1B $1B–$5B Over $5B

Less than 5 min 5-to-15 min 15-to-30 min


30 min to 1 hour 1-to-2 hours More than 2 hours

9.3% 8.5% 4.2% 8.2% 8.2%4.1%

24.7%

15.1%

31.5%

16.4%

19.7%

16.4%

11.5%

29.5%

14.8%

9.9%

11.3%

23.9%

28.2%

22.5%

9.6%

16.0%

13.8%

35.1%

17.0%

11.3%

14.9%

16.0%

29.6%

19.1%

95.4%94.9%

86.1%87.0%

82.4%

44.4%38.8%

13.5%12.7%

6.3%14.1%

83.3%

Windows Media

RealPlayer

QuickTime

MPEG

Customized

Other

0% 20% 40% 60% 80% 100%

Aberdeen SMI

Source: Aberdeen Group and streamingmedia.com, January 2004

MPEGPlayer12%

QuickTime21%

RealPlayer22%

WindowsMedia40%

No answer2%

Other3%


hands-on guide to webcasting: internet event and av production (hands-on guide series)

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