Hardware is a general term for the physical artefacts of a technology. It may also mean the physical components or items of a computer system that you can see or touch. The major forms of multimedia Hardware are discussed below:
3.1.1 CD STORAGE
A compact disc, or CD, is a thin wafer of clear polycarbonate plastic and metal measuring 4.75 inches (120mm) in diameter, with a small hole, or hub, in its centre. The metal layer is usually pure aluminium, sputtered onto the polycarbonate surface in a thickness measureable in molecules. As the disc spins in the CD player, the metal reflects light from a tiny infrared laser into a light-sensitive receiver diode. These reflections are transformed onto an electrical signal and then further converted to meaningful bits and bytes for use in digital equipment.
CDs (compact discs) are used to store data for use in a variety of devices, including computers and CD players. The main or standard type of CD is called a CD-ROM; ROM means read-only memory. It can be played back or read by just any CD player as well as most computers that have CD drives. One is the CD-R, which is the typical choice for an individual who only wants to add data files or music to a CD once. An individual uses a CD burner, which is a component of many modern computer systems, to record to these discs.
Some recordable CDs are classified as CD+R. This type of disc allows consumers to record music or data to it, but provides nearly twice the amount of space that is available with a CD-R. A CD-RW also has a place among the recordable CDs. This one is a bit different, because it allows consumers to erase it and record over it again. Otherwise, it can be used in the same manner as CD-Rs and CD+Rs.
Diagram of different types of Compact Disc.
DVD, which stands for Digital Video Disc, Digital Versatile Disc, is the next generation of optical disc storage technology. This disc has become a major new medium for a whole host of multimedia system: It’s essentially a bigger, faster CD that can hold video as well as audio and computer data. DVD aims to encompass home entertainment, computers, and business information with a single digital format, eventually replacing audio CD, videotape, laserdisc, CD-ROM, and perhaps even video game cartridges. DVD has widespread support from all major electronics companies and all major computer hardware companies.
It’s important to understand the difference between DVD-Video and DVD-ROM. DVD-Video (often simply called DVD) holds video programs and is played in a DVD player hooked up to a TV. DVD/ROM holds computer data and is read by a DVD-ROM drive hooked up to a computer. The difference is similar to that between Audio CD and CD-ROM. DVD-ROM also includes future variations that are recordable one time (DVD-R) or many times (DVD-RAM). Most new computers with DVD-ROM drives will also be able to play DVD-Videos.
3.1.3 UNIVERSAL SERIAL BUS (USB) USB has effectively replaced a variety of interfaces such as serial and parallel ports. It can connect computer peripherals such as mice, keyboards, digital cameras, printers, personal media players, flash drives, Network Adapters, and external hard drives. For many of those devices, USB has become the standard connection method. USB was designed for personal computers, but it has become commonplace on other devices such as smart phones, PDAs and video game consoles, and as a power cord.
USB devices are linked in series through hubs. There always exists one hub known as the root hub, which is built into the host controller. So-called sharing hubs, which allow multiple computers to access the same peripheral device(s), also exist and work by switching access between PCs, either automatically or manually. Sharing hubs are popular in small-office environments.
A physical USB device may consist of several logical sub-devices that are referred to as device functions. A single device may provide several functions, for example, a webcam (video device function) with a built-in microphone (audio device function). Such a device is called a compound device in which each logical device is assigned a distinctive address by the host and all logical devices are connected to a built-in hub to which the physical USB wire is connected.
Diagram of Universal Serial Bus
3.1.4 MICROSOFT DIRECTX
Microsoft DirectX is a collection of application programming interfaces (APIs) for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. Originally, the names of these APIs all began with Direct, such as Direct3D, DirectDraw, DirectMusic, DirectPlay, DirectSound, and so forth. The name DirectX was coined as shorthand term for all of these APIs (the X standing in for the particular API names) and soon became the name of the collection.
Direct3D (the 3D graphics API within DirectX) is widely used in the development of video games for Microsoft Windows, Microsoft Xbox, and Microsoft Xbox 360. Direct3D is also used by other software applications for visualization and graphics tasks such as CAD/CAM engineering. As Direct3D is the most widely publicized component of DirectX, it is common to see the names “DirectX” and “Direct3D” used interchangeably.
The components of DirectX are
- DirectDraw: for drawing 2D Graphics (raster graphics).
- Direct3D (D3D): for drawing 3D graphics.
- DXGI: for enumerating adapters and monitors and managing swap chains for Direct3D 10 and up.
- Direct2D for 2D Graphics
- Direct Write for Fonts
- Direct Compute for GPU Computing
- DirectInput: for interfacing with input devices including keyboards, mice, joysticks, or other game controllers.
- DirectPlay: for communication over a local-area or wide-area network.
- DirectSound: for the playback and recording of waveform sounds.
- DirectSound3D (DS3D): for the playback of 3D sounds.
- DirectMusic: for playback of soundtracks authored in DirectMusic Producer.
- DirectX Media: comprising DirectAnimation for 2D/3D web animation, DirectShow for multimedia playback and streaming media, DirectX Transform for web interactivity, and Direct3D Retained Mode for higher level 3D graphics. DirectShow contains DirectX plugins for audio signal processing and DirectX Video Acceleration for accelerated video playback.
- DirectX Diagnostics (DxDiag): a tool for diagnosing and generating reports on components related to DirectX, such as audio, video, and input drivers.
- DirectX Media Objects: support for streaming objects such as encoders, decoders, and effects.
3.1.5 ACTIVE MOVIE
Active Movie is a streaming media technology now known as DirectShow, developed by Microsoft to replace Video for Windows. ActiveMovie allows users to view media streams, whether distributed via the Internet, an Intranet or CD-ROMs.
When ActiveMovie was installed, an option was added to the Start Menu to launch the
ActiveMovie Control. This allowed users to play multimedia files and thus was a rudimentary media player. In March 1997, Microsoft announced that ActiveMovie was going to become part of the DirectX set of technologies, and by July it was being referred to as DirectShow.
SELF ASSESSMENT EXERCISE
Identify four types of multimedia hardware systems
From our studies in this unit, we have seen that there are different types of multimedia hardware systems. It is equally pertinent to note that the hardware system cannot function effectively without the software component of multimedia systems.
A multimedia system is not different from any other type of computer system except for its ability to process multimedia data. Thus, it should have features that can process audio, video, graphics and animation. In this unit, we looked at the fundamental types of multimedia hardware systems such as CDs, DVD, USBs, Microsoft DirectX and the Active Movie. We hope you found the unit enlightening. To assess your comprehension, attempt the questions below.
6.0 TUTOR MARKED ASSIGNMENT
1). List the types of multimedia systems?
2). Explain the difference between the types of multimedia hardware systems you have