take video or still images and transmit them over the Internet. Unlike digital cameras,
webcams have no storage capacity. Most plug into a USB port, but some also use
IEEE 1394 or parallel ports. Webcams are typically used in live chat situations, or
face-to-face video calling, and offer resolutions ranging from sub-VGA to up to 2
million pixels. Some offer autofocus and zoom features to improve image quality,
and have built-in microphones.
Digital cameras have largely replaced conventional film cameras for both amateur
and professional photography. These cameras use CMOS or CCD sensors to record
images onto internal or card-based flash memory form factors such as
compact flash
,
SD, memory sticks, xD-picture cards, and smart media. These images can be
transferred to computers for emailing, printing, or storage via flash memory card
readers or direct USB port connections.
Musical instrument digital interface, or MIDI music is created from digitized samples
of musical instruments that are stored in the ROM or
RAM
of a MIDI device such as
a sound card, and played under the command of a MIDI sequencer. MIDI sequences
are then stored as files for future playback, and can be transferred between sound
cards and MIDI-enabled devices such as keyboards via the MIDI port.
Sound cards
are typically used to record and play back analog audio, but are also
used to play back digital audio sources as well. When recording analog sources such
as CDs, sound cards digitize the audio at varying sample rates and store files in
uncompressed forms like WAV, or compressed forms like WMA and MP3. Most
cards support 5.1 or 7.1 surround sound audio.
Video capture cards are used to capture live video from sources like analog
camcorders, TV, and more. Most recent capture cards with video capture capabilities
are multi-purpose cards that include other functions like TV tuner and video capture
functions, graphics cards with video-in/video-out S-video or composite video ports,
and
USB devices
. Videos are stored in a variety of formats, such as MPEG, AVI, and
more.
Task 2. Speak about multimedia devices answering the questions.
1.
What electronic device have bought recently and can you describe it?
2.
What are the most popular multimedia devices in the world?
3.
Should children be taught multimedia devices at school as a subject?