2. Demands placed on hardware by multimedia systems

The developments in information technology have allowed people to create multimedia products that were once only developed by film professionals. 

The hardware of a multimedia system places limits on the quality and size of the multimedia product that can be produced or displayed. 

For this reason, a multimedia system makes use of the latest technology, such as a fast processor, large primary storage, high-resolution screen, quality speakers, and the latest in disk drives.

Students Learn About:

  • The demands placed on hardware by multimedia systems, including:
    • Primary and secondary storage requirements as a result of:
      • bit depth and the representation of colour data
      • sampling rates for audio data
    • Processing as a result of:
      • video data and frame rates
      • image processing, including morphing and distorting
      • animation processing, including tweening
    • display devices as a result of pixels and resolution





  • summarise current information technology requirements for multimedia systems







  • distinguish between different approaches to animation including path-based and cell-based through practical investigations
Introduction to Binary Systems - Digital from Analogue

Multi Binary examples.mp4


characteristics of multimedia systems


Image storage
Images place extra demands on the multimedia system including storage. The current image being displayed is stored in a section of memory called the frame buffer.When selecting images to include in a multimedia product, it is important to consider the format of the image and the resolution of the presentation device.
Large high-resolution images may affect the performance of the multimedia product. An image with high resolution will require more memory than an image with low resolution. The storage requirements of an image are dependent on the number, size, tone and colour of each pixel. The relationship between the image on the screen and the bits in memory is called bit mapping, or memory mapping. It is dependent on the bit depth.

Bit depth (or colour depth or pixel depth) for images is the number of bits per pixel. One or more bits must be stored for each pixel on the screen. At the simplest level, one pixel can represent one bit, where a 0 bit means the pixel is off and a 1 bit means the pixel is on. 

Example: What is the file size in kilobytes of a black-and-white image with a resolution of 640 by 400 pixels?

File size = Horizontal × Vertical × Bit depth
                8 × 1024 bits (= 1 KB)
            = 640 × 400 × 1
                8 × 1024
            = 31.25 KB (Kilobyte)

Colour graphics and graphics with tones (or grey scale) increase the number of bits per pixel and require more storage. Colour graphics are obtained from an RGB (red-green-blue) screen that uses a combination of red, green and blue colours. The minimum number of colours is eight: red only; green only; blue only; red and green (yellow); red and blue (magenta); blue and green (cyan); red, green and blue (white); and no colour (black). For example, as shown in Table 7.1, a bit depth of 8 allows a graphic to contain 256 colours, or 64 colours each with 4 tones (64 × 4 = 256), or 32 colours each with 8 tones (32 × 8 = 256). Photo realistic
images require at least 24-bit colour.

Example: What is the file size in kilobytes of a 256-colour image with a resolution of 1024 by 768 pixels?

File size = Horizontal × Vertical × Bit depth
                            8 × 1024
            = 1024 × 768 x 8
                    8 × 1024
            = 768 KB







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