VBrick Systems MPEG-4 User manual

VBrick Systems MPEG-4 User manual
HOW TO SERIES
MPEG-4 In A Web Page
It’s easier than you may think
Embedding video in a web page has many advantages over standalone desktop players. Beyond the ability to customize the look-and-feel
of the viewer’s experience, embedded players can be automatically
installed, can provide viewing statistics via conventional web logs, and
allow a certain degree of security.
Player Basics
Virtually all modern streaming video players for the Windows
environment are built as “ActiveX Controls” (a Microsoft name for
“Comm Objects”) that fit into the DirectShow environment. As a result,
when you install a stand-alone player you have usually installed the
components necessary for embedding the video in a web page. But
when you install an embedded player, you do not have the stand-alone
player. A stand-alone player is typically a set of user interfaces (“skins”)
that use various additional components, including the player ActiveX.
There is little functional difference between an “embedded player” and a
“stand alone player”. Rather, there is a “player object” that is useful by
itself, and an application that bundles this object with other features and
functions. Player vendors, including Real, Apple, and Microsoft, all
create a stand-alone player that implement additional features beyond
what is reasonable for just the video player object. For example, the
QuickTime player ActiveX and the Real player ActiveX can play video
but they do not report statistics. The stand-alone player can report
statistics because they include functions beyond the player object itself.
This keeps the player object smaller, more “lightweight”, and good
appropriate for automatic download and installation.
You probably realize that for embedding video in a web page, we are
interested in just the player object, conveniently packaged as an ActiveX
control. But with many possible players, how does your computer
identify which one to use?
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
GUID
Every ActiveX object has a Globally Unique Identification number, or
GUID. For example, the GUID for QuickTime is “02BF25D5-8C17-4B23BC80-D3488ABDDC6B”. When your browser sees this identifier, it
knows which software (the player itself) to use.
Each player object has various parameters, properties and methods
available that are unique to each player.
Plug-Ins
The VBrick StreamPlayer is unique. It is not a “player” at all! Rather, it
is a group of special components that enable Windows Media Player to
display live MPEG-1, MPEG-2 and MPEG-4. The group includes the
VBrick Program Guide, Source Filters, and both MPEG-2 and MPEG-4
audio/video decoders.
Just like Windows Media has its very own GUID (6BF52A52-394A11D3-B153-00C04F79FAA6), so do the VBrick components.
As long as the components are available on your computer, they can be
called from a web page. Importantly, it does not matter the source of the
web page…it could be a page you encounter on any public web site, or
an html page saved on your local computer. Basically, the html code
tells the browser to find a software component already on the computer,
and then tells that component what to do. In this way, the browser
doesn’t really display video – it simply instructs a compatible component
to do it.
But it is inconvenient to install components manually, especially if we are
talking about serving the half-billion people connected to the Internet!
Happily, ActiveX components can be automatically installed from any
web server via a “CAB” file. You can think of a CAB file as a specialized
“zip” file that includes installation instructions. When your browser
encounters an object (a GUID) that includes a CODEBASE statement,
your browser will do several things. First, it will check to see if that
GUID is already present on your computer. Next, it will check the
revision. If you don’t already have the component, or if the component
specified in the web page is a later version that what you have, your
browser will automatically download and install it. Now, if there is a new
version of the component, you need only change the revision date on
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
one web page, and all viewers will get the update the next time they visit
your page!
The Code
Let’s start with Windows Media Player. Here is the code for Media
Player version 9:
<object classid="clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6" id="wmplayer"
width="352" height="240">
<param name="URL" value>
</object>
You can learn about each parameter from the Microsoft player SDK, but
note that the first parameter is called “URL”. If you want to display a live
MPEG-2 video stream, you cannot simply enter the IP address of the
stream because the player does not know how to play standard streams.
In order to play live MPEG-1, MPEG-2, or MPEG-4, you need the VBrick
components. The components will “intercept” the URL, configure the
necessary MPEG decoders, and tells the Media Player window to
display the video.
The easiest thing to do is to include the VBrick components on the same
page as Media Player. To install these components, the following code
is included on the page:
<object classid="clsid:0249ED44-B640-45BD-8066-17F81BFDC050"
CODEBASE="http://www.vbrick.com/CAB/STREAMPLAYER1.cab#Version=1,0,0,2"
</object>
<object classid="clsid:85887165-031A-4297-BC4E-6B246C120B9C"
CODEBASE="http://www.vbrick.com/CAB/STREAMPLAYER4.cab#Version=1,0,0,2"
</object>
Note that the object includes a CODEBASE statement that will load the
component directly from the VBrick web site.
It is not necessary to include this code on every page. In fact, it is
perfectly acceptable to include the above objects only on one page,
such as an entry portal, as long as the page is viewed at least once. Its
only purpose is to install the components. Once the components are
installed they are ready to work. However, it is good practice to include
the code on every viewing page to ensure the viewer has the latest
code, regardless of how they entered your site (remember, the
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
components are automatically downloaded and installed only if needed,
and if they are already present and up to date, nothing happens).
As discussed earlier, if a desktop installation of VBrick StreamPlayer
Plus is conducted, the components are already present, but including
the above code will do no harm.
MPEG URL’s
To display a live MPEG-1 or MPEG-2 video stream in Media Player,
simply use the following for the URL:
vbricksys://ip=ipaddress&port=portnumber&license
If you have a multicast stream at 239.1.1.1 on port 4444, your code will
look like this:
<html>
<head>
<Title> VBrick Sample </title>
<body>
<object classid="clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6" id="wmplayer"
width="245" height="240">
<param name="URL" value=”vbricksys://ip=239.1.1.1&port=4444&License=your license
string”>
</object>
<object classid="clsid:0249ED44-B640-45BD-8066-17F81BFDC050"
CODEBASE="http://www.vbrick.com/CAB/STREAMPLAYER1.cab#Version=1,0,0,2"
</object>
</body>
</html>
When you view the page, live MPEG video is instantly displayed! An
alert is issued if you do not use a valid VBrick license.
Displaying of MPEG-4 via RTSP unicast, is equally easy. For example,
if your VBXcast has an IP address of 192.168.1.1, and your stream
name is “vbrickvideo1” your html code would be:
<html>
<head>
<Title> VBrick Sample </title>
<body>
<object classid="clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6" id="wmplayer"
width="245" height="240">
<param name="URL" value=”vbrtsp://192.168.1.1/vbrickvideo1”>
</object>
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
<object classid="clsid:85887165-031A-4297-BC4E-6B246C120B9C"
CODEBASE="http://www.vbrick.com/CAB/STREAMPLAYER4.cab#Version=1,0,0,2"
</object>
</body>
</html>
Note that for MPEG-4, you simply use “vbrtsp://” (Microsoft does not
appear to properly support the standard protocol). The special VBrick
component will intercept the “vbrtsp://” and use the RTSP standard for
communications with the video source.
Support for the reception of MPEG-4 multicast is more complex. You
have three choices:
1. Configure your VBXcast to multicast your MPEG-4 video, then
press the “Create SDP File” in your VBXcast and save the SDP
file. Locate the SDP file on a web server. Use the full path name
to this SDP file in the player’s URL parameter (e.g. in place of
“vbrtsp://192.168.1.1/vbrickvideo1” above).
2. Use Javascript or VBscript to program the VBrick components to
identify the multicast stream and launch the player. Details on
scripting VBrick’s StreamPlayer are in the “VBrick Video Toolkit”.
3. Use StreamPlayer or StreamPlayer Plus that automatically
displays a Program Guide of multicast video streams.
Internet Viewing
VBrick StreamPlayer components are ideal for use in any network where
UDP streaming is allowed. However, because StreamPlayer does not
support HTTP tunneling, it may not be the best choice for a universal
“consumer” MPEG-4 video viewing. QuickTime may be used in to
support both UDP and HTTP, although the viewer will need to manually
set the “Streaming Transport” preference.
That HTTP streaming is of interest may seem odd when you realize that
the VBXcast itself only delivers the more-efficient UDP1. But when a
VBXcast feeds a reflector server, both UDP and HTTP streaming is
supported.
1
Due to overhead, HTTP streaming uses 30% more bandwidth per stream than does UDP.
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
Embedded QuickTime
QuickTime version 6 supports MPEG-4 directly, and like many players
may be automatically installed.
To embed QuickTime in a web page, use this code:
<OBJECT CLASSID="clsid:02BF25D5-8C17-4B23-BC80-D3488ABDDC6B"
WIDTH="276" HEIGHT="189"
CODEBASE="http://www.apple.com/qtactivex/qtplugin.cab">
<PARAM name="SRC" VALUE="myvideo.mov">
<PARAM name="AUTOPLAY" VALUE="true">
<PARAM name="CONTROLLER" VALUE="false">
<EMBED SRC="myvideo.mov" WIDTH="360" HEIGHT="250" AUTOPLAY="true"
CONTROLLER="false"
PLUGINSPAGE="http://www.apple.com/quicktime/download/">
</EMBED>
</OBJECT>
Information about each QuickTime parameter can be found on the Apple
web site.
Note that embedded QuickTime wants to see the SRC parameter set to
a “.mov” file, and not a “rtsp://” stream. In this example, the “.mov” file is
simply a QuickTime “reference movie” that need contain nothing more
than the “rtsp://” address of your live stream. You simply create this
reference movie and place it on your web server and point the player to
it as shown.
For multicast, simply create a SDP file from your VBXcast, place it on
your web server, and point QuickTime to this file in place of the .mov file.
Audience Participation
Having live MPEG-4 video that you can broadcast to virtually everyone,
anywhere is powerful. You can give a live presentation, tutorial, product
launch, religious service, and much more.
But as you give a live talk, how can your audience ask questions?
There are at least four answers:
1. Use a telephone – have your audience call you, ask their question,
then hang up. Like a “Radio Talk Show”, it is very necessary that
the caller turn off their sound to avoid echo. The delay through the
Internet streaming system can vary from a few, to many seconds.
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
Avoid using a speakerphone. Use of a telephone tends to defeat
the purpose and the spirit of live webcasting, and should be used
only when there is a very small audience or when there are no
alternatives.
2. Use email – have your audience send questions to you via email.
This is a good solution because it is universally supported.
3. Use Instant Messaging – form a “IM Community” using popular
Instant Messaging services, free or otherwise. The disadvantage
is this does not scale well to very large audiences, and not
everyone may have access to the IM service (AOL, MS, Netscape,
etc.).
4. Create Chat Page – There are many free chat room services that
can be easily integrated along with your live MPEG video.
Typically, this is implemented in a frame set where your video is
one frame page and your chat page is another. You can easily
host your own chat page using applications such as
ASPChatWorks, available for free download from
http://www.freevbcode.com/ShowCode.Asp?ID=858. VBrick does
not endorse or support this application, but it is implemented on
the VBrick web site and successfully used for live webcasting
sessions. For a modest fee, superior Java Applets exist on the
open market that provide moderated chat and other advanced
features. A modestly competent webmaster can create a
video/chat frame set in only a few hours.
Synchronized Graphics
As we’ve seen, with VBrick it is very easy to send great video with great
sound to everyone in an enterprise, or via the Internet, everyone in the
world. But many presentations benefit from the use of charts and
graphics, such as PowerPoint slides. How can these be included in a
live electronic presentation?
One way to do this is with VBrick’s free SCAT (Screen Capture And
Transfer) tool and your web server. SCAT will automatically capture
your desktop image (for example, a full screen PowerPoint show slide)
and send the image to your web server when you press a key. The
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
name of the image is the same each time you do a capture, so the
JPEG image on your server is always the one you last sent.
All you need to do is simply construct a web page that includes that
image from your web server, and use a Java Applet that refreshes the
image on a periodic basis. Along side that image, simply include your
embedded video and you instantly have live video along with images
that display in near real time under control of the presenter.
For networks using multicast, the same approach can be used, but
inexpensive 3rd party software (such as www.videoalive.com) can deliver
graphics via multicasting, saving web server cost and providing virtually
infinite scale.
Many other 3rd party tools exist that can be used to deliver images along
with your video.
Novice Instruction
You do not need webmaster skills, or even web authoring software, to
embed video in a web page. Just follow these simple instructions:
1. Open your “My Documents” folder.
2. Select File -> New -> Text Document, or just open Notepad if you
know how.
3. Copy the following into your new Notepad document:
<html>
<head>
<Title> VBrick Sample </title>
<body>
<object classid="clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6" id="wmplayer"
width="245" height="240">
<param name="URL" value=”vbrtsp://192.168.1.1/vbrickvideo1”>
</object>
<object classid="clsid:85887165-031A-4297-BC4E-6B246C120B9C"
CODEBASE="http://www.vbrick.com/CAB/STREAMPLAYER4.cab#Version=1,0,0,2"
</object>
<object classid="clsid:0249ED44-B640-45BD-8066-17F81BFDC050"
CODEBASE="http://www.vbrick.com/CAB/STREAMPLAYER1.cab#Version=1,0,0,2"
</object>
</body>
</html>
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
4. If you want to view MPEG-4 from your VBXcast, edit the line that
says value=”vbrtsp://192.168.1.1/vbrickvideo1” and change it to
your VBXcast IP address and stream name. If you want to view
live MPEG-1 or MPEG-2 video sent via multicast, edit the line to
read “vbricksys://ip=ipaddress&port=port”.
5. Select “Save As” and save the document with any name you like.
6. Rename the document with a “.htm” extension.
7. Double-click on the document. Your IE browser will launch and
you will see your live video.
Security
While not foolproof, your web page with embedded video can easily be
made more secure by simply password-protecting it. By locating your
web page in a password-protected directory on your web server, or
through the use of ASP, CGI or similar, your page may only be
accessible to those with the password. Of course, anyone who knows
the address of the stream itself can still gain access, but it would be very
difficult to guess this address. For example, if your RTSP stream name
was “/xyz123” instead of “/sales”, it would be very difficult to guess.
Thus, the name of the stream becomes another “password”, and it you
have reasonable assurance that only those whom you have given
access can view your video.
Making multicast stream secure is more problematic, but once again a
reasonable degree of security is available my simply not broadcasting
the Program Guide, using obscure addresses and port numbers,
protecting the MPEG-4 SDP file, and/or using the VBrick Category
feature.
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
Quick Reference
Item
StreamPlayer Package 1
GUID
0249ED44-B640-45BD8066-17F81BFDC050
StreamPlayer Package 4
85887165-031A-4297BC4E-6B246C120B9C
BB370BA2-725A-47e39459-0EF542B2FFC4
0005C928-1B6D-43fbBAE0-3783E03FA9CF
VBexchange component
VBrick Program Guide
Windows Media Player 9
QuickTime 6
RealOne
6BF52A52-394A-11D3B153-00C04F79FAA6
02BF25D5-8C17-4B23BC80-D3488ABDDC6B
CFCDAA03-8BE4-11CFB84B-0020AFBBCCFA
Comments
Package of multiple components needed
to decode MPEG-1 and MPEG-2, and to
provide multicast Program Guide.
Package of multiple components needed
to decode MPEG-4.
Component to detect and format MPEG4 multicast with script.
Component to detect and display live
MPEG-1, MPEG-2 and MPEG-4
Program Guide
Video player from Microsoft
MPEG-4 player from Apple
Requires 3rd party plug-in to display
MPEG-4
HOW TO SERIES – Embed MPEG Video
Copyright 2003 VBrick Systems, Inc.
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