subject: The Difference Between Drivers And Codecs [print this page] Computer programs or devices which encode or decode digital data signals are known as codecs. "Codec" is a word derived from combining the words coder and decoder, making for an easy way to distinguish and remember the function of a codec.
Originally, codecs were hardware devices, often confused with modems. Codecs convert audio analog into a digital signal called Pulse-Code Modulation (PCM), then converts it back into analog so there is no compression of the signal. Modems convert digit data from a computer to an analog signal which can be transmitted over a telephone line. On the receiving end of the line, another modem then converts the signal back to digital for use by another computer.
Codecs today are considered software programs, whose function is encoding a data stream to be transmitted, encrypted, or stored. A codec likewise decodes the signal when it is time to be edited or played back. To add to the confusion, "codec" has come to be used as a generic reference for a video conferencing device.
In video conferencing and in streaming media, codecs are used in the video camera's analog-to-digital converter, or ADC. The ADC converts the analog signals to digital, which are then compressed to be re-transmitted or stored. A receiving device must then decompress the video, running it through a digital-to-analog converter (DAC) to allow end-user analog display.
Codecs are not the same thing as drivers. While drivers are also computer programs, they are used to allow a computer's system programs to interact with hardware that has been installed on a computer.
When a new hardware device is plugged into a computer through a USB or "bus" connector, for example, the device requires the installation of a software package which allows the device to be used. This driver program is normally included in the hardware package, so the device can be used immediately upon installation of the device and the software.
A driver works when the computer interacts with a specific routine in the driver program, asking the driver to tell the device what to do. The driver is the "middle-man" between computer and hardware, making it essential to enjoying peripherals such as video devices, digital cameras, sound cards for audio, microphone headsets, printers and scanners.
Drivers do not work unless the devices they command are present and connected to the computer. When a device is plugged into the computer, the computer will send a message to the user that "new hardware" has been detected. Without the driver software, the computer cannot interact with the device, rendering the device useless.
Drivers are specific to the make and type of hardware they drive, and are also specific to the system that is using them. When purchasing a headset, for example, the computer systems which the driver can be used with are notated on the product package. Therefore, it's important to know the type of computer operating system the device will be installed on, so the proper driver for that system can be installed.
