Video making

Digital Camera Works

You can use a digital camera to take photos that the camera stores internally on a memory card. You can then connect the camera to your computer and transfer some or all of the photos to your hard drive.

Megapixels
One of the most important features of a digital camera is the number of megapixels, which measures the detail in each photo. A megapixel
represents a million pixels. (See the section “Discover Digital Images” to learn more about pixels.) The number of megapixels affects the quality of the image; the more megapixels, the better the picture. A lowend camera may take photos that are 2 or 3 megapixels, while better cameras take photos that are 8 or 9 megapixels or more.

Memory
All digital cameras have some form of internal memory — usually in the form of a memory card, such as a CompactFlash card — that they use to store the photos that you take. If you take a photo that you do not like, you can delete it from memory and try again. The amount of memory affects the number of photos that the camera can store internally, and so the more memory the camera has, the more photos it can store.

Features
Today’s digital cameras come with many of the features that are found in film cameras, including built-in flashes and zoom lenses. Most digital cameras also come with LCD screens, and many are also able to capture short video sequences.

Transfer Photos
When you are ready to work with your photos, connect your digital camera to your computer. Most digital cameras connect through a USB cable. Then use the software that came with the camera to transfer the images to your computer. When the transfer is complete, delete the images from the camera so that you can store new
photos.

How a Digital Video Camera Works

You can use a digital video camera to record videos that the camera stores internally. You can then connect the video camera to your computer and transfer the video to your computer for editing.

Megapixels
Similar to a digital still camera, the quality of the digital video camera image is also rated by the number of megapixels it supports. Digital video cameras use an internal chip called a Charged Coupling Device
(CCD) to capture video, and different CCDs support different levels of detail. Most current digital video cameras come with CCDs
that support between 2 and 5 megapixels. Some older or low-end digital video cameras use CCDs that support only about 700,000 pixels.

Storage
Digital video cameras store your video footage internally until you are ready to transfer the footage to your computer. Digital video cameras use a wide variety of storage devices, from MiniDV cassette tapes, to memory cards such as MultiMedia and Secure Digital, to recordable DVD discs. If you capture footage that you do not like, you can erase it and try again. Most MiniDV tapes hold between 60 and 120 minutes of video, and recordable DVDs hold between 30 and 120 minutes. For cameras that use memory cards, the more memory the camera has, the more video it can store.

Features
Most digital video cameras come with an LCD monitor and zoom controls, and some have the ability to take still pictures. Most digital video cameras can capture footage at 30 frames per second (fps), which produces smooth motion. However, some cameras can only record 320-x- 240-pixel videos at 30 fps; at the regular size, 640-x-480- pixel video, they can only capture 15 fps.

Transfer Videos
When you are ready to work with your videos, you can connect your digital video camera to your computer. Most digital video cameras connect to the computer using a USB cable, although some cameras use a FireWire cable (also called IEEE 1394 or iLink). You can then use the software that came with the camera to transfer the video footage to your computer. When the transfer is complete, either insert a new tape, card, or disc, or delete the footage from the camera, so that you can store new videos.

How a Webcam Works

You can use a Webcam, also called a PC cam, to capture live
photos directly to your computer or to an Internet site.

You can also use a Webcam to record live video for use in video
conversations or video e-mail.

Live Photos
Most Webcams come with special software that enables you to capture live photos at regular intervals. You can then send each new photo to your Web site to create a constantly updated view of a scene or object. Most Webcam software also enables you to send a photo through e-mail.

Live Video
Many Webcams can also capture live video directly to your computer, which is useful for Internet-based video conversations or videoconferencing. For most Webcams, you face a trade-off between the size of the video and number of frames captured per second. For example, a Webcam may capture a 352-x-288-pixel video at 30 frames per second, or a 640-x-480-pixel video at 15 frames per second.

Video Conversation
A video conversation, or video chat, is an Internetbased form of communication in which two people can both see and hear each other. To have a video conversation, both parties need a Webcam, a sound
card, speakers, and a microphone. Many Webcams have built-in microphones, and software such as Windows Messenger or OS X iChat. For more information,

Video E-mail
A video e-mail is an e-mail message that includes a video captured by a Webcam as an attachment. Most Webcam software programs enable you to capture the live video stream, compress it, and then attach it to an e-mail. Video e-mail is a convenient way to pass along
short home movies to friends or family who do not have a Webcam of their own.

Site Monitoring
A Webcam is a useful tool for monitoring a site. For example, you could enhance the security of your home or office by using a Webcam to monitor a live feed of your front door or a secure area. Similarly, many parents use Webcams to monitor toddlers and children. Some
Webcams have built-in motion sensors, so that they transmit video only when they detect movement.

How a Digital Audio Player Works

You can use a digital audio player, also called an MP3 player, to store and play digital music files. Digital audio players are small, lightweight, and sturdy, so you can listen to music while walking, jogging, or performing errands.
Some popular digital audio players include the Apple iPod, the Microsoft Zune, the SanDisk Sansa, the Creative Labs Zen Vision,
and the Toshiba GigaBeat.

Storage
Most digital audio players store music files internally using flash memory, memory chips that allow for quick recording and erasing of files. The flash memory is built either into the player or on removable memory cards, such as CompactFlash cards. 512MB of flash memory is enough to store about eight hours of music. Some players, such as the Apple iPod and the Microsoft Zune, have internal hard drives that can store anywhere from 1GB to 80GB of music, or between 16 and 1,280 hours of music. Most players support at least two music file formats: MP3 and WMA. For more about these file types, see “Understanding Digital Audio.”

Features
Digital audio players range from simple devices that only play music
to more complex machines that offer a number of extra features. For
example, many players have FM tuners that enable you to listen to FM
radio. Other players have built-in microphones for voice recording. For walking or jogging with your player, you might need either an arm strap or a belt clip.

Access Music

Most digital audio players connect to the computer through a USB cable. The players also use software that enables you to organize your music files and send them to the player. Your operating system also has builtin software that allows you to organize and play music files:
Windows Vista has Windows Media Player, and OS X has iTunes.
The simplest way to get music onto your digital audio player is to first
transfer one or more tracks from an audio CD to your computer. You can then upload those tracks to your player. Alternatively, go to an Internet site that offers digital music files, such as MP3.com or Apples iTunes Music Store.

Discover Digital Images

Pixels
A pixel, short for picture element, is a tiny square of light on your screen. Everything you see on your computer is displayed by changing the colors of individual pixels. A typical screen can have anywhere
from 480,000 to nearly 2 million pixels, arranged in a row-and-column grid.

Resolution
The image resolution is given by the density of the pixels in the image. The higher the resolution — that is, the higher the pixel density — the sharper the image. Image resolution is measured in pixels per inch, or PPI. Typical values are 75, 150, and 300 PPI.

Color Quality
The color quality, also called the bit depth, is the number of possible colors used in an image. The higher the color quality, the sharper your images appear. Common color quality values are 256 colors (also called 8-bit color), 65,536 colors (16-bit), and 16 million colors (24-bit).

Work with Images
You can use image-editing software to view and edit your digital images. For example, you can change the image size, crop out elements that you do not want, or add special effects. You can print the photos on a color or photo printer, or you can have a photo store
print them for you.

Image Compression
To make large digital files easier to manipulate, most images are compressed to a certain extent to make them smaller. Some formats use lossy compression, which removes portions of the image that are
redundant or unneeded. Other formats use lossless compression, which maintains the integrity of the original image. In general, lossy compression generates files that are smaller but of poorer quality
than files generated by lossless compression.

File Formats
You can save digital image files in a variety of formats, each of which has its own features and advantages. For example, BMP (bitmap) images use lossless compression and are good for color drawings. JPEG images use lossy compression, and the resulting small files are good for uploading to a Web site or sending through e-mail. TIFF images use lossless compression and are good for rendering photos and scanned images.

Learn About Digital Video

A digital video is a series of consecutive pictures that produce
a moving image that exists in an electronic format. Examples of
digital video include files transferred from a digital video
camera, live feeds from a Webcam, DVD movies, and animations. Once you have digital videos on your computer, you can incorporate them into presentations, e-mail messages, and Web pages.
Understanding digital videos requires that you learn about a few
fundamental concepts, such as frame rates, video size, video compression, and video file formats.

Frame Rate
The frame rate measures the number of still images, or frames, that a digital video file displays every second. The frame rate is measured in frames per second (fps). The higher the frame rate, the smoother the motion appears in the digital video; however, this results in a larger file and the need for more processing power. The two most common
frame rates for digital video are 30 fps (full-motion video), which produces smooth motion, and 15 fps, which produces jerky motion.

Video Size
The video size measures the dimensions — the width and height — of the video frames, expressed in pixels. For example, a 320-x-240-pixel video has frames that are 320 pixels in width and 240 pixels in height. The greater the video size, the larger the file size, and the more processing power that is required to play the file. The most common digital video sizes are 320 x 240, 640 x 480, and 720 x 480, also called full-screen video.

Work with Videos
After you transfer the video to your computer, you can use video-editing software to view and edit the video. Windows Vista offers Windows Movie Maker, and OS X offers iMovie. There are also third-party products such as Adobe Premier and Roxio VideoWave. You can rearrange clips, add sound effects, and insert transitions
between scenes.

Video Compression
Digital video files can be huge, and so some compression is required to make the files easier to work with. All video compression formats use lossy compression, which removes portions of the video that
are redundant or unneeded. For example, the compression may record only the data that changes from one frame to another, rather than entire frames.

File Formats
You can save digital video files in a variety of formats, each of which has its own features and advantages. The most common format is MPEG (Motion Picture Experts Group), which uses lossy ompression and has three main standards: MPEG-1, which produces near-VHS-quality video; MPEG-2, which produces DVD-quality video; and MPEG-4, which is an enhanced version of MPEG-2 that produces even smaller files.
WMV (Windows Media Video) is similar to MPEG-4, but produces even smaller files. AVI files are limited to 320 x 240 pixels at 30 fps, but are supported by all versions of Windows. You can play uickTime files on both Mac and Windows computers.

Understanding Digital Audio

Digital audio is any sequence of sounds that exists in electronic
format, including music, audio CDs, sound effects, recorded
sounds, and the narration or soundtrack that accompanies a
digital video. Once you have digital audio on your computer, you can
listen to it as well as incorporate it into presentations, digital video
projects, and Web pages. Understanding digital audio requires
that you learn about a few fundamental concepts, such as digital
sampling, bit rates, MP3s and other audio file formats, and music licensing.

Digital Sampling
Digital sampling is the process by which an analog sound wave is converted into a digital format. A sample is a snapshot of the sound wave at a given moment. The sample is a measurement of the
wave’s height (its loudness or amplitude), and these measurements are taken at discrete intervals to form a digital approximation of the original wave.

Bit Rate
The bit rate, also spelled bitrate, measures the digital sampling rate that s used to create a digital audio file. Bit rate is measured in thousands ofbits per second (Kbps). Although a higher bit rate results in a better sound quality, it also results in a larger file. For example, a digital audio file sampled at 128 Kbps (called near-CD quality) sounds better than one that is sampled at 64 Kbps (called FM radio quality), but the resulting file is twice as large.

MP3s
The Motion Picture Experts Groups Audio Level 3, or MP3, is one of the most popular audio file formats. It compresses digital audio by removing extraneous sounds that are not normally detected by the human ear. This process results in high-quality audio files that
are one-tenth the size of uncompressed audio, thus making MP3s ideal for downloading and storing on digital audio players (which are frequently called MP3 players, even when they support other audio
formats).

Other File Formats
Besides MP3, digital audio comes in a number of other file formats. The most popular of these is Windows Media Audio (WMA), which produces audio files with the same quality as MP3, but that are
compressed to about half the size. WMA is often used for digital audio player storage because it can fit twice the number of songs as MP3. The WAV format is supported by all Windows versions, but it is
uncompressed and so is suitable for only short sound effects or snippets. Less popular audio formats are MIDI, AIFF, and AU.

Work with Digital Audio
You can use audio-editing software to play and edit your digital audio. For example, you can delete portions of the file, change the volume or speed, and add special effects. You can also use some audioediting
programs to record sounds through a microphone or from an external audio source such as a turntable, cassette player, or digital audio tape
player.

Digital Audio Licenses
Some digital audio content is in the public domain, which means that you can use it without paying for it. However, most digital audio content — particularly commercial music — is protected by copyright. This means that legally you should not play the audio unless you get permission or pay a fee. In either case, you are given a digital license that allows you to play the audio file, and that may also place restrictions on whether you can copy the file to devices other than
your computer.

Copy Music CD Tracks to Your Computer

You can add tracks from a music CD to the Library in Windows
Media Player. This enables you to listen to an album without
having to put the CD into your CD or DVD drive each time.
The process of adding tracks from a CD is called copying, or
ripping, in Windows Vista. The Library helps you to organize and
manage audio files on your computer After you add a music track, you can play it from the Library tab.

1 Insert a CD into your computer’s CD or DVD drive. Note: If the AutoPlay window appears, click .
2 Click the Rip tab.
3 If you have multiple disc drives, click
the drive containing the music CD.
Copy Music CD Tracks to Your Computer
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Windows Media Player displays a list of
the CD’s tracks.
4 Click the CD tracks that you do not
want to copy ( changes to ).
5 Click Start Rip.

Windows Media Player begins copying the
track or tracks.
l The Rip Status column displays the copy
progress.
l If you want to cancel the operation before
it is complete, you can click Stop Rip.
l After each file is copied, the Rip Status
column displays a Ripped to library
message.
l The copy is complete when all the tracks
you selected display the Ripped to library
status.

Capture Video on Your Computer

You can capture video footage from a VCR or camcorder by
digitizing the footage and transferring it to your computer’s hard drive.
You can use special software to edit the captured footage and add special effects. If the finished video is not too large, you can e-mail it or place it on a Web site. You can also transfer it to a DVD.

Analog to Digital
Videotape is an analog medium, and so you will need special equipment to view videotape on your computer. To work with the footage on your computer, you must first convert the analog tape to
a digital video file. For more information, see the section “Watch TV on Your Computer.”

Video Capture Device
You can use a video capture device to digitize videotape and transfer it to your computer’s hard drive. Although some video capture devices are internal circuit boards, most are external devices, which are easier to install. Make sure that the device is also capable of capturing audio, either directly or indirectly through your computer’s sound card.

Attach Cables
Attach a VCR or camcorder to the video capture device using RCA cables — yellow for the video, and red and white for the right and left audio streams — or an S-Video cable. Then attach the video capture
device to your computer. Most video capture devices connect to the computer using a USB cable. However, some devices connect using RCA cables or a FireWire cable (also called IEEE 1394 or iLink).

Capture Video
Insert a tape in the VCR or camcorder, and then fast forward or rewind the tape to the position where you want to start capturing your video. Open the videocapture device software, start its capture feature, and then begin playing the videotape. The program
captures the video stream and saves it to your hard drive. When you have digitized the footage that you need, stop the capture operation and then stop the tape.

Edit Video
Most video capture devices have software that enables you to trim the digital video (remove scenes from the beginning or the end), and delete scenes. You can also add background music, sound effects
narration, overlay titles, and add between-scene transitions and other effects.

Create a DVD
Some video-capture device software also enables you to create DVD discs from the captured video. In some cases, the software captures the video and then sends it directly to a recordable DVD disc. In most
cases, you use a software program to choose the digital video that you want to work with, create DVD menus and chapters, and then copy the result to a recordable DVD.

Watch TV on Your Computer

With the appropriate hardware, you can attach a television cable
to your computer and then watch television on your computer monitor. Local News This is useful if you are busy working and do not want to miss a TV program, or if you enjoy performing other activities, such as surfing the Internet, while watching TV.

TV Tuner
You can use a TV tuner to capture an incoming TV signal and display it on your computer’s monitor. Although some TV tuners are internal circuit boards, most are external devices, which are easier to install.

Attach Cables
You can attach a TV cable to the TV tuner’s cable jack. Alternatively, you can run RCA cables or an S-Video cable from your TV’s output jacks (if it has them) to the corresponding ports on the TV tuner. You can then attach the TV tuner to your computer. Most TV tuners connect to the computer using a USB cable. However, some TV tuners connect using RCA cables or a FireWire cable (also called IEEE 1394 or iLink).

Watch TV
All TV tuners have software that enables you to view and control the TV signal. You can open the TV tuner software, tune to the channel that you want, and then start watching. Some TV tuners are equipped with a remote control that enables you to change channels and adjust the volume from a distance.

Digitize TV
Some TV tuners also double as video capture devices, thus enabling you to digitize the TV signal and save it to your hard drive. In most cases, you can either grab still images from the signal or save entire programs. Note, however, that recording at DVD quality means that a
typical one-hour TV show uses up about 2GB of hard drive space.

Personal Video Recorder
Some TV tuners turn your computer into a personal video recorder, which enables you to record TV programs to your hard drive as you watch them, or at scheduled times. You can also pause, rewind, and fast forward live TV, as well as watch instant replays.