Difference between Frame Buffer and Display Buffer

What is a Frame Buffer?

Difference between Frame Buffer and Display Buffer

A frame buffer is a significant amount of computer memory that is continuous. Each pixel in the raster has at least one memory bit; this quantity of memory is referred to as a bit plane. The images are constructed in the frame buffer one bit at a time.

Because a memory bit has only two states, a single bit plane produces a black and white display. You are aware that a frame buffer is a digital device, whereas a CRT is an analog one. As a result, when information is received from the frame buffer and shown on the raster CRT graphics device, a conversion from a digital representation to an analog signal must occur. A digital to analogy converter (DAC) can be used for this. Before a pixel in the frame buffer can be shown on the raster CRT, it must be accessed and transformed.

Additional bit planes are used to include colour or gray scales into a frame buffer raster graphics device. Each pixel's intensity on the CRT is controlled by a pixel position in each of the N bit planes. Each of the N bit planes' binary value is stored into the relevant places in a register. The resultant binary integer is interpreted as a degree of intensity ranging from 0 (dark) to 2n -1 (full intensity).

There are three fundamental colours, a simple colour frame buffer with three-bit planes, one for each primary colour, is constructed. Each bit plane is responsible for driving a separate colour gun for each of the three major colours used in colour video. The CRT combines these three primaries (red, green, and blue) to produce eight colours.

What is a Display Buffer?

Difference between Frame Buffer and Display Buffer

The phrase "display buffer" refers to any memory space that contains visual data that is meant to be shown on a screen. This might contain the frame buffer, but it could also include additional memory locations such as video RAM (VRAM) or graphics processing unit (GPU) video memory.

  • Display buffers can be implemented in several methods, such as frame buffers, VRAM, or GPU memory.
  • Textures, cursors, and typefaces can all be stored in display buffers.
  • Display buffers can also be used to save intermediate picture data that the GPU is processing, such as rendered frames and depth buffers.
  • In certain circumstances, the terms "display buffer" and "frame buffer" are used interchangeably. It should be noted, however, that the display buffer can also refer to other memory locations that contain picture data.

Let’s see the key differences between Frame Buffer and Display Buffer:

CharacteristicsFrame BufferDisplay Buffer
PositionFrame Buffer located at the video cardDisplay buffer located at Video card, GPU, VRAM
ObjectiveThe picture data that is now displayed on the screen is saved.Image data that is meant to be shown on a screen is saved.
ImplementThe video card uses this to create the video signal that is transmitted to the display device.The video card, GPU, or VRAM can use this to create the video signal that is transmitted to the display device.

More Differences

  • Frame buffers are always visible, whereas display buffers are not always visible. The image that is now displayed on the screen is stored in the frame buffer. Texture buffers and depth buffers, for example, may or may not be visible at any one time.
  • Frame buffers are usually read-only, although display buffers can be read/write. Only the frame buffer can be written to by the GPU, although it can read from other display buffers. This enables the GPU to have access to intermediate picture data while it is being processed.
  • Frame buffers are normally implemented as a single continuous block of memory, although display buffers might be implemented as a series of smaller memory blocks. Because the frame buffer must be read and written to very rapidly, it is critical to reduce the time it takes to access individual pixels. Other display buffers may not require as speedy read and write operations; hence they can be implemented as smaller blocks of memory.
  • The image that is now displayed on the screen is stored in the frame buffer. The memory that contains the picture data that is displayed on the screen is known as the display buffer. The projector is used to read picture data from the display buffer and display it on the screen of a movie theatre.

Examples of Frame Buffer and Display Buffer

Frame Buffer Examples

  • The current image is shown on the screen.
  • Creating 3D graphics.
  • Creating animation.

Display Buffer Examples

  • Keeping textures used to render 3D visuals.
  • Keeping track of cursors and typefaces.
  • Keeping intermediate visual data that the GPU is processing.

Conclusion

In conclusion, the frame buffer is the most significant display buffer in general since it is directly responsible for showing the image on the screen. Other display buffers, on the other hand, can be used to hold picture data that is meant to be displayed on the screen.