| Multimedia Technology |
Microsoft DirectShow
(formerly called Microsoft ActiveMovie?) is a media-streaming architecture for the
Microsoft WindowsR platform that enables the high-quality capture and playback of
multimedia streams. The streams can contain video and audio data compressed in a wide
variety of formats, including MPEG, Apple QuickTime, audio-video interleaved (AVI), and
WAV files. Capture can be based on either Video for Windows (VFW) or Windows Driver Model
(WDM).
DirectShow is integrated with Microsoft DirectXR technologies so that it automatically
takes advantage of any accelerating video and audio hardware to deliver the highest
possible performance. For developers of Internet and intranet applications and content,
the Windows Media Player control included with DirectShow enables playback of a host of
popular media types on the local computer and on the Internet. It also provides a
comprehensive set of services for playback of MPEG movies and DVD-Video. The Windows Media
Player control replaced the ActiveMovie control for media playback beginning with DirectX
Media 6.0. Streaming Media Services (Netshow Service)
Windows NT Server NetShow Services enable Internet providers and organizations to deliver
the highest-quality audio and video at every bandwidth across the Internet or enterprise
networks. One of the streaming media components of the WindowsR Media Technologies,
NetShow Services consist of server and tools components for delivering audio, video,
illustrated audio, animations, and other multimedia types over networks.
NetShow Services include a comprehensive suite of authoring tools and streaming services
to provide everything developers need to deliver audio, video, illustrated audio,
animations, and other multimedia over a network or the Internet. A software developer's
kit (SDK) is available allowing any developer to write new tools or extend existing
applications to work with NetShow Services or ASF content. Many third-party tools are
available that extend the functionality of the tools that ship with NetShow Services.
Deploying NetShow Services is made easy with wizards and templates for server setup and
configuration.
AAF, or Advanced Authoring Format, is an
industry-driven, cross-platform, multimedia file format that will allow interchange of
media and compositional information between AAF-compliant applications. These applications
are primarily content creation tools such as Adobe Premiere, Photoshop and AfterEffects,
Avid Media Composer and Cinema, Sonic Foundryˇ¦s Sound Forge, and SOFTIMAGE|DS, to name a
few.
The Advanced Authoring Format (AAF) is an industry initiative by the Promoters, for the
purpose of specifying an extensible, platform-independent multimedia file format to meet
authoring application interchange needs.
The Advanced Streaming Format (ASF) is a
powerful, extensible, synchronized multimedia file format. It expands upon existing
formats (for example, WAV and AVI) and incorporates new media types, scalable codecs,
improved editibility, media stream prioritization, and enhanced indexing. It is designed
to support the streaming of multimedia over a network from a media server or from an HTTP
server as well as for local playback, all over a wide range of bandwidth and usage
scenarios. Content compatibility is a design point for ASF: The explicit goal of ASF is to
supercede legacy formats (for example, AVI and WAV) in order to provide a basis for
industry-wide multimedia interoperability, with ASF being adopted by all major streaming
solution providers and multimedia content generation (tools) companies.
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| Component Software |
How to call interface member functions in both C
and C++,illuminating the role of a client and the differences between the
languages, using the context of COM's memory management facilities. As a prelude to this
discussion, we'll also look into basic requirements such as COM initialization for all
COM/OLE applications or components that make up a task. The next major section,
"Implementing an Object in C and C++," describes an object's perspective on
creating interfaces in both languages and introduces the idea of enumerator objects. If
you are reading this book to gain an architectural understanding of OLE, you'll want to
read the first parts of that section to understand these types of objects and skip the
code discussion. The section "Implementing Multiple Interfaces" will examine
three different ways in C++ to implement an object with multiple interfaces, giving you
some options for your own work. "Implementing Reusability" will illustrate
containment and aggregation in the form of sample code. "Interfaces and OLE API
Functions" describes the differences among and functionality of the various OLE
interfaces and API functions. The Component Object Model
(COM) is a software architecture that allows applications to be built from
binary software components. COM is the underlying architecture that forms the foundation
for higher-level software services, like those provided by OLE. OLE services span various
aspects of commonly needed system functionality, including compound documents,custom
controls, interapplication scripting, data transfer, and other software interactions.
ActiveX brings innovation and
interactivity to the Web. Because it is supported by many different languages and tools,
it enables developers with varied backgrounds and expertise to bring their creativity to
the Web. Based on a refinement of the existing COM standard already known by thousands of
developers, it can leverage the knowledge and work of the development community without a
steep learning curve. And because it is a third-generation technology with extensive
third-party support, it provides the richest development platform for both Internet and
intranet Client/Server applications available today. ActiveX takes the most creative and
innovative software development efforts and enables them to work together seamlessly in a
Web site. With thousands of these software components already existing, an exciting
collection of interactive objects is available for immediate use by Web producers. |
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| Database |
The ActiveX Data Objects (ADO)
programming model represents the best of the existing Microsoft data access programming
models. If you are familiar with Data Access Objects (DAO) or Remote Data Objects (RDO),
you will recognize the interfaces and will be able to work with them very quickly. You
will also notice considerable improvements in the model, and tasks that were awkward in
previous models have either been fixed or eliminated from the ADO model.
The ADO objects provide you with the fastest, easiest and most productive means for
accessing all kinds of data sources. The ADO model strives to expose everything that the
underlying data provider can do, while still adding value by giving you shortcuts for
common operations.
ADO is Microsoft's strategic, high-level interface to all kinds of data. ADO provides
consistent, high-performance access to data, whether you're creating a front-end database
client or middle-tier business object using an application, tool, language, or even an
Internet browser. ADO is the single data interface you need to know for 1- to n-tier
client/server and Web-based data-driven solution development.
ADO is designed as an easy-to-use application level interface to Microsoft's newest and
most powerful data access paradigm, OLE DB. OLE DB provides high-performance access to any
data source, including relational and non-relational databases, email and file systems,
text and graphics, custom business objects, and more. ADO is implemented with a small
footprint, minimal network traffic in key Internet scenarios, and a minimal number of
layers between the front-end and data source-all to provide a lightweight,
high-performance interface. ADO is easy to use because it is called using a familiar
metaphor - the OLE Automation interface, available from just about any tool and language
on the market today. And since ADO was designed to combine the best features of, and
eventually replace RDO and DAO, it uses similar conventions with simplified semantics to
make it easy to learn for today's developers. JDBC
is a Java API for executing SQL statements. (As a point of interest, JDBC is a trademarked
name and is not an acronym; nevertheless, JDBC is often thought of as standing for
"Java Database Connectivity".) It consists of a set of classes and interfaces
written in the Java programming language. JDBC provides a standard API for tool/database
developers and makes it possible to write database applications using a pure Java API.
Using JDBC, it is easy to send SQL statements to virtually any relational database. In
other words, with the JDBC API, it isn't necessary to write one program to access a Sybase
database, another program to access an Oracle database, another program to access an
Informix database, and so on. One can write a single program using the JDBC API, and the
program will be able to send SQL statements to the appropriate database. And, with an
application written in the Java programming language, one also doesn't have to worry about
writing different applications to run on different platforms. The combination of Java and
JDBC lets a programmer write it once and run it anywhere.
Java, being robust, secure, easy to use, easy to understand, and automatically
downloadable on a network, is an excellent language basis for database applications. What
is needed is a way for Java applications to talk to a variety of different databases. JDBC
is the mechanism for doing this.
JDBC extends what can be done in Java. For example, with Java and the JDBC API, it is
possible to publish a web page containing an applet that uses information obtained from a
remote database. Or an enterprise can use JDBC to connect all its employees (even if they
are using a conglomeration of Windows, Macintosh, and UNIX machines) to one or more
internal databases via an intranet. With more and more programmers using the Java
programming language, the need for easy database access from Java is continuing to grow.
MIS managers like the combination of Java and JDBC because it makes disseminating
information easy and economical. Businesses can continue to use their installed databases
and access information easily even if it is stored on different database management
systems. Development time for new applications is short. Installation and version control
are greatly simplified. A programmer can write an application or an update once, put it on
the server, and everybody has access to the latest version. And for businesses selling
information services, Java and JDBC offer a better way of getting out information updates
to external customers.
Only with the DAO (abbreviate of Data Access Objects ), if you want to get all the
VB's database functions with simple few words.DAO had been found in Microsoft's Access
database,then it had used by VB 3.0 version. At least,it becomes the standard of access
database.And it's to be the relational Microsoft's products(included of VC++ˇBOffice
series.) |
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