Audio and Video devices are devices that capture audio(sound) and/or images or video inputs, generating a signal that can be accessed by other devices. The input device may not necessarily produce a signal but just record the input onto a storage medium, an example of this would a camera. In other cases the input device, such as a microphone, may produce a signal.
Audio Input Devices
Audio input is the process of entering or recording music, voice, or sound effect into the computer. A computer must have a sound card installed before it can input sound. Audio input devices include microphones, headsets, tape or audio cassette recorder/players, MIDI (electronic keyboard or piano)
Microphone and Headset
A microphone, sometimes called mic, is an acoustic-to-electric transducer or sensor that converts sound into electrical signals. A headset is a set of headphone and an in-built microphone. With a microphone or headset plugged into the sound port, one can record voice or sound using the Windows Sound Recorder programme into the computer for editing.
Microphones and headsets are used in many applications including telephones, tape recorders, hearing aids, motion picture production, radio and television broadcasting, and many more. Another use of microphone and headset is in the speech or voice recognition system which is the computer’s capability of distinguishing spoken words.
Tape or Audio Cassette Recorder/Player
Tape or Audio Cassette Recorder/Players are used to record music and speeches into the computer. Once they are plugged into the sound port, music and speeches recorded on magnetic tapes and compact discs can be played and the sound transferred into the computer.
MIDI (Musical Instrument Digital Interface) devices are electronic musical keyboards or pianos for playing music. These are electronic organs which produce synthesized audio tunes for music production that can also be stored in the computer through the sound card.
Video Input Devices
Video input devices capture and enter full motion or static recording of events into the computer. They include the digital cameras and video digitizer.
Digital cameras work much like the conventional film cameras but instead of recording images on films they record them on a digital storage medium, such as flash memory card, digital tape cartridge, built-in hard disk drive, or DVD. Two types of digital cameras are digital still cameras and digital video cameras.
Digital still cameras are designed for everyday consumer use with some more expensive ones having removable lenses designed for professional use. Digital video cameras are commonly used by individuals and businesses to capture or transmit video images. Two types of digital video cameras are digital camcorders and computer video cameras.
Webcams are designed to transmit video images over the internet. They are used in video conferences and video phone calls where both the sender and receiver of the message or those engaged in the communication are made visible to each other on the internet. Webcams are often built into computers particularly notebook computers and are also available as stand-alone devices.
A video digitizer is used to capture individual frames from a video and then save them as still pictures in a file. With this device attached to the computer one can stop a video as one watches a film and capture any single frame as still picture and save it into the computer.