PROJECT (EXAMPLE)

PRACTICAL XIV – RESEARCH PROJECT

Duration of Examination: 3 hrs

Maximum Marks: 100

Credits: 3

Students Must do research on any chosen topic in Visual Communication after getting formal approval from the HOD. The research is qualitative research purely based on the data available in the Books, Journals and New Media with a department staff as guide. The research Report to be submitted in duplicate and the student has to appear for a VIVA VOCE  to be conducted by one internal and one external examiner on the day of practical examination.

INTERNSHIP(EXAMPLE)

ADVERTISEMENT PRODUCTION-PRACTICAL

THIRD YEAR - VI SEMESTER

ADVERTISEMENT PRODUCTION-PRACTICAL 

Duration of Examination: 3 hrs

Maximum Marks: 100

Credits: 3

q  Students should handle non-linear editing with AVID software.

q  Students should handle digital camera with MD9000 and trained in multi-camera setup.

q  Shoot an AD FILM- duration 1 minute.

q  Shoot a Corporate film 10 Minutes. (10sec, 20sec &30sec)

VIDEO BASIC AND TERMINOLOGY
(VIDEO BASIC: Video Standards, Video as Digital Data, 24FPS (Frame per Second), Color and Video,
Computer Graphics Vs Video Graphics, Audio)

(TERMINOLOGY: Screen Formats, Video Fundamentals, Audio Fundamentals, Analog Video Formats, Digital Video Fundamentals, Digital Video Formats, Digital Audio Formats, Digital Data Rates, Video Editing - Clips and Tracks,
Video Compositing, Audio Editing and Effects)

 VIDEO BASIC

What is video?

The Series of Framed images put to together one after another, to simulate creation and interaction.

What is video editing?

The process of manipulating the video footage in correct form.

VIDEO STANDARDS: 

NTSC, NTSC-J, PAL, PAL-M, SECAM

NTSC - National TV Standards Committee, PAL - Phase Alternating Line

(NTSC  -  525 Horizontal Scanlines, 30fps, used in North and Central America, Philippines, South Korea and Taiwan)

(NTSC J – 525 Scanlines, 30fps, used in Japan, same as NTSC but Darker Black than NTSC)

(PAL - Has higher resolution, 625 Scanlines, 25fps, used in Europe, Parts of Asia, Pacific and South Africa)

(PAL M - 525 Scanlines, 30fps, with PAL Color Palette, used in Brazil)-like NTSC video with PAL Colors

(SECAM - 625 Scanlines, 25fps, with PAL Color, used in Russia, France, Middle East and North Africa)

PAL - Sharper Image, More Flickers (sharper image because of scanlines, flicker because of frame rate)

NTSC - Poorer Resolution, Less Flicker (poorer resolution because of scanlines, less flicker because of frame rate)

PROGRESSIVE Vs INTERLACED:

Videos are made up of series of Horizontal Lines is called Scanlines.

Progressive Scan displays all scanline from top to bottom sequentially like 1,2,3,4 to bottom line of the entire image. (E.g. Computer Monitor - CRT not LCD).

Interlaced Scan contains two separate fields, one is odd numbers fields (1, 3, 5…) others are even number fields (2, 4, 6…).First its display odd numbers fields then even number field. By viewing both fields together they create single frame.

Progressive        - Advantage       : Higher image quality
                                  Disadvantage : Not Broadcast compatibility (expect HD)

Interlaced           - Every other line, Broadcast compatibility

Fields means scanline. Even and Odd fields means Upper and Lower fields

FRAME RATES:

FILM – 24fps (In Theater – 24fps, Digitized – 23.98fps) (Digitized – 23.98fps)

PAL – 25fps (actually run at 25 frames)

NTSC – 30fps (Theoretically 30fps, Actually – 29.97fps)

A ‘Frame’ is a complete image composed of two fields

A ‘Field’ is all the even or odd numbered lines in a frame

VIDEO FORMATS:

DV – Digital Video / SD – Standard Definition / HD – High Definition

DV cameras are Mini DV, DVCPro-25, and DVCAM.

SD cameras are DVCPro-50, Betacam SX, Betacam SP, DigiBetacam.(everyday used in broadcast,cable casting and high end co-operate market)

HD cameras are HDV, DVCPro-HD (100), and HD.

IMAGE SIZE:

DV – NTSC 720x480, PAL 720x576

SD – NTSC 720x486, PAL 720x576

Video compression require 4x4 pixel squares, that why 6 pixel is important in NTSC

HD – There is 18 different scan rates are available provide by FCC
            HD 480i & p = 720x480 (Broadcast Image size)
            HD 720i & p = 1280x720
            HD 1080i & p= 1920x1080
           
(1080i, 720p are two most popular flavors of HD video. All HD formats are 16:9)

HDV –   Actually shoots 1440x1080
                JVC – 1280x720p
                Sony – 1920x1080i

Aspect ratio – It’s a number that describe the relationship of width of the picture/height of the picture

Pre-1950’s movies 4:3 (1.33:1)
Disney Cartoons 1.66:1
Movies today 16:9 (1.78:1)
Epic Movies 2.35:1

SD – 4:3
HD – 16:9 vs. 4:3 

Letterboxing – Adding black bars at the top and bottom of the screen to fit 16:9 image onto a 4:3 Screen.

Pillarboxing – Adding black bars to the sides of the screen to fit 4:3 image to a 16:9 screen           

VIDEO OUTPUT:

There is two way to connect video deck to computer
                1.Analogue (composite, s-video, component
                2.Digital (firewire, SDI)

VIDEO AS DIGITAL DATA:

Higher Data Rates = Greater Quality

CD audio = 176KB/s (44.1 Hz 16-bit sampling rate)

Data CD = 153KB/s

DV = 3.75 MB/s

SD Uncompressed 8-bit = 20.2 MB/s

SD Uncompressed 10-bit = 26.7 MB/s

HDV 720p = 2.4 MB/s (low end)

HDV 1080i = 3.2 MB/s (low end)

HD 1080i Uncompressed = 160 MB/s

DATA STROAGE:

1 hour DV = 13 GB

1 hour HDV 720p = 8.7 GB

1 hour HDV 1080i =11.5 GB

1 hour 8-bit uncompressed SD = 72.7 GB

1 hour 10-bit uncompressed SD = 96 GB

1 hour HD 1080i = 560 GB

Old Internal Hard Disk data rate = 20-25 MB/s

New Internal Hard Disk data rate = 40-50 MB/s

RAID – Redundant Array of Inexpensive Disks
(Record and playback vast amounts of information very quickly)
(Use for both data storage and data throughput)

COLOR SAMPLING:

Is used to reducing the color information to reduce the video file size

DV = 4:1:1 (very difficult to chroma-key)

DVD/PAL = 4:2:0

Digibeta = 4:2:2

Uncompressed = 4:4:4

HD = varies between 4:2:2 (broadcast) 4:4:4 (digital cinema)

HDV = 4:2:0

Note: Chroma-keying needs lots of color information to work well, decreasing color sampling impacts chroma-keying and other color work

Chroma-key Software

Ultimatte – define and isolate color in a 3-d space

Primatte – looks for a specific frequency of color

IMAGE COMPRESSION:

1. Frame-Based
2. GOP-Based (Group of Pictures)

GOP: I-frame – a complete image; starts the GOP B and P-frames describe the changes to the previous frame in the current frame

DVD – 15 image GOP 200 KB/sec (probably 12 images)

Digibeta – Frame based 27 MB/sec

HDV – users GOP compression (To edit HDV, the GOP must be decoded and turned back into individual frames

TIME CODE:

A label that uniquely identifies each frame of video, expressed as hh:mm:ss:ff

Two types of time code:

a.       Non-Drop frame

b.      Drop frame

Note: No quality difference between non-drop and drop frames
           (we are dropping timecode labels, not actual video frames)

Non-Drop Frame: Uniquely identifies each frame used in commercial, film and animation.

Drop Frame: Used to exactly match the running time against real time anything broadcast longer that one minute. (Role: Every frame has a label every minute (expect the tenth), two frames are dropped.

Non-drop frame               = 00:00:59:29 -> 00:01:00:00
Drop frame                         = 00:00:59:29 -> 00:01:00:02

CODEC (short for: COmpressor/DECompressor):

There are four principal goals to consider when choosing a codec:

1. The size of the compressed file
2. The speed of compression
3. The speed of decompression
4. The quality of the final image

There are also a lot of codecs specifically for the web. Web codecs are designed to reduce file size and decompress quickly, however, they take longer than real-time to compress:

• H.261
• MPEG-4
• VC H.263
• H.263
• H.264
• Sorenson Video 3
• Sorenson Video

Choosing a Video Codec

As you are starting to see, the list of codecs we can use for video (fast compression and fast decompression) is starting to dwindle.

• The first, and best, rule to keep in mind when choosing a video codec is to select the codec that matches the format of the video you are editing. Thus, if you are shooting NTSC DV, the DV/DVCPRO - NTSC codec is the best one to choose. (Outside the US, use the DV - PAL codec with your PAL DV video.)
• The second rule is if you are selecting a codec to integrate multiple video formats choose the codec that provides the highest quality.
• The third rule is to select your codec based upon your final output format.

These rules are made to be broken. However, before you start breaking rules willy-nilly, you should probably get a better understanding of what the impact is of selecting a specific codec.
In general, image quality increases with file size. As file size increases, you need bigger and faster hard disks; at some point, the files are so big they can't be played from an external FireWire drive.
Here's a table that ranks codecs from higher quality to lower for SD video. The rules are the same for HD, but the files are bigger. Data rates and storage for NTSC and PAL are essentially equivalent.

Codec	Quality	Approx. data rate	Space to store 1 hour of video
Animation*	Excellent	41 MB / second	147 GB
Uncompressed 10-bit	Very Good	26.7 MB / second	96 GB
Uncompressed 8-bit	Good	20.2 MB / second	72 GB
DVCPro-50	Good	7 MB / second	25 GB
DV	OK	3.75 MB / second	13 GB

* The Animation codec supports video, but is not generally used for real-time playback.

Then there are specialized codec’s that significantly compress video for off-line, low-resolution work that would not be used in the final version of the program:

• Offline RT
• Motion JPEG A
• Motion JPEG B
• Photo-JPEG
• JPEG 2000

24FPS (FRAME PER SECOND):

Advantages:

·         Progressive look

·         No interlace artifacts

·         Cleaner still frames

·         More believable motion blur

·         Simplifies layback to film

·         Smaller file size when outputting to DVD

Disadvantages:

·         No benefit shooting 24 fps when it is not the speed of final output

·         24 fps progressive video is always displayed as interlaced video for PAL and NTSC

·         24 fps DVDs can’t be played on older DVD players

Best to Shoot:

·         30 fps for NTSC

·         25 fps for PAL

·         24 fps for Film

24fps Capturing:

Telecine is process of converting physical film to either video or data

Pulldown frame means repeating a frame periodically to convert from 24 to 30 fps
( A – A – B – B – B – C – C – D – D – D )
                    2 : 3 : 2 : 3

Converting FROM 24 fps

25 fps = speed up 4%
30 fps = pulldown frames

Three popular cadences

·         2:3:2:3 is best for telecine, difficult to digitize

·         2:3:3:2 is best for digitize, easy to remove pulldown frmes

·         2:2:2:4 is best for computer, very quickly digitized pulldown frames

Note: Never removes frames from NTSC or PAL

COLOR AND VIDEO:

White Balancing: Adjusting colors inside the camera to compensate for lighting conditions so that white objects are recorded as white.

Color Space: A way of defining colors; for example, RGB, YUV and CMYK.

Basic Color Spaces:

·         RGB                       - Red, Green and Blue (used in monitors)

·         CMYK                    - Cyan, Magenta, Yellow and Black (used in printing)

·         HSV                        - Hue, Saturation and Value (used lot in computer graphics)

·         YUV                       - Traditional analog description of video color which includes black, white                  
                              and some color information in a same signal.

·         Y’CrCb                   - Same as YUV but its more accurate in color information

COMPUTER GRAPHICS Vs VIDEO GRAPHICS:

Video was invented about forty years before computers; which means that computers were able to improve on the lessons we learned during the development of video. Because of this, there are six major differences between graphics on video and graphics on the computer. Keeping these in mind will help you improve the look of your text.

These seven differences are:

• Video is fixed resolution, computer resolution varies
• Video displays interlaced images, computers display progressive images
• Video gamma is different from computer gamma
• Video white is grayer than computer white
• Video uses YCrCb colors, which are more restrictive than the computer's RGB colors
• Video colors are not as precise as computer colors
• Video pixels are rectangular, the computer's are square

Let's take a look at each of these and see what problems they cause.

Video pixels are rectangles

Of all the problems between computers and video, this one causes the most confusion. While most High-Def video uses square pixels, NTSC and PAL do not. Both are rectangles, an NTSC pixel is tall and thin, while a PAL rectangle is short and fat.
This means that when we create graphics on our computer, we sometimes need to take this into account. I say sometimes because Final Cut is inconsistent in how it deals with imported graphics. Here's the scoop: if you are creating single layer graphics, such as scans or text supers, to import into FCP, you must adjust your image size for the difference between square and rectangular pixels. If you are creating multi-layer PhotoShop graphics, you don't.
Here's a table that will help you better plan your images. This assumes you want all images imported full-screen with no moves on the image.

Video pixel dimensions
Video format	Single layer	Multi-layer	Video image
DV (4:3)	720 x 540	720 x 480	720 x 480
DV (16:9)	853 x 480	720 x 480	720 x 480
SD (4:3)	720 x 547	720 x 486	720 x 486
SD (16:9)	853 x 486	720 x 486	720 x 486
PAL (4:3)	768 x 576	720 x 576	720 x 576
PAL (16:9)	1024 x 576	720 x 576	720 x 576
DVD (4:3)	720 x 534	720 x 534	720 x 480
DVD (16:9)	853 x 480	853 x 480	720 x 480
HD 720	1280 x 720	1280 x 720	1280 x 720
HD 1080	1920 x 1080	1920 x 1080	1920 x 1080

If you want to create a still image big enough for camera moves, multiply each of the single layer dimensions by 2.5. For example, an SD DV 4:3 image size that I recommend would be 1800 x 1350 x 72. This works great for moves on scanned images. Same for HD. Final Cut can handle images up to 4,000 x 4,000 x 72. However, in generally, keep your images as small as possible to prevent Final Cut from choking.

Tips to Improve your Text

So, given all these constraints, it's a wonder we can create anything on our computers that displays properly on video. But, we can. And here are some tips that can help.

1. Avoid lines thinner than 4 pixels, they will flicker
2. Avoid lines that are almost horizontal or almost vertical, they will stair-step
3. Avoid fancy, curvy fonts like Harrington, Chancery, or Savoye
4. Avoid fonts with very thin bars or serifs, such as Engravers, Baskerville, or Modern
5. Avoid point sizes smaller than 24 points
6. Avoid saturated colors, use the Vectorscope if you are unsure
7. Avoid whites brighter than 92% (235 in PhotoShop)
8. Always use drop shadows on any text you want your viewers to read
9. Always keep any text you want viewers to read inside Title Safe
10. Keep text on screen long enough for you to read it three times.

Action Safe: Contains all essential action 5% in from all edges

Title Safe: Contains all text and essential logos 10% in from all edges

Computers are progressive

Video is interlaced

White Vs Superwhite

DV records

·         Black = 0

·         White = 109%

Broadcast-safe white = 100% or Lower

Above 100% are called Superwhite (not Broadcast-safe)

If you are outputting to analog or broadcast, whites cannot be above 100%

Computer graphic white levels are 109% by default

Pixel Aspect Ratio:

·         Computer: 1:1

·         NTSC: 1:0.906

·         PAL: 1:1.06

·         HD: 1:1

PAL

·         4:3(image): 720 x 576

·         4:3(TIFF): 768 x 576

·         16:9(anamorphic): 1024 x 576

NTSC

·         4:3(image): 720 x 480

·         4:3(TIFF): 720 x 540

·         16:9(anamorphic): 853 x 480

NTSC - SD

·         4:3(image): 720 x 486

·         4:3(TIFF): 720 x 547

·         16:9(anamorphic): 853 x 486

AUDIO:

Sampling: Measures the audio at a specific time and assigns an average value.
                    The more samples you have, the better the frequency response of the audio

Bit-Depth: Bit depth determines the dynamic range of audio – the distance
                     between the softest and loudest passages.

8-bit used for Internet and Broadcast

16-bit used for CD-audio, Video Production and Post-production

24-bit used for Theatrical and DVD-Audio

Sampling rates determine frequency response.

Bit depth determines dynamic range.

Audio mixing:

Never let your audio clip lights activate

Dialogue              :               -6db to -12db

Sound Effects    :               -12db to -18db

Music                    :               -18db

VIDEO BIT DEPTH:

Why Video Bit Depth Matters

All shades of gray, and shades of a color, are represented by a numeric value. In 8-bit video, these values range from 0 - 255. In 10-bit video, these values range from 0 - 1023. In both cases, 0 represents the absence of something, either white or a color, while either 255 or 1023 represents the maximum amount of white, or a color.

To solve these problems, ProRes allows you to store both SD and HD video using 10-bit values, but at file sizes up to 33% smaller than uncompressed SD files and 90% smaller than uncompressed HD files. This allows us to take advantage of the improved image quality 10-bit video offers, without totally overloading our hard drives with massive files.

Here are some general rules you can use:

• 8-bit video files are smaller than 10-bit, however, color fidelity can suffer
• 8-bit files are perfectly OK for off-line and/or rough-cut uses
• 8-bit images are generally OK for images that don't have lots of color saturation or effects
• 10-bit files are better for mastering
• Using ProRes for mastering SD video will, probably, look better than native DV. Your file sizes, however, will increase to 65 GB per hour of video at a data rate of 18.125 MB/second.
• Using ProRes for mastering HD video will, probably, look better than native HDV, DVCPROHD, XDCAM, and the same as HDCAM or HDCAM SR. Your file sizes will be up to 99 GB per hour, at a data rate of 27.5 MB/second. These files will be much bigger than similar HDV or XDCAM, bigger than DVCPROHD and much, much smaller than HDCAM and HDCAM SR.

Note: Frame rate and image size will impact file size, these estimates assume worst case. Apple indicates under "normal conditions" we should expect file sizes about 30% smaller than my numbers.

 

VIDEO TERMINOLOGY

SCREEN FORMATS:

Aspect ratio -- The shape of an image or frame, expressed as the width-to-height ratio. Widescreen film uses a 16:9 aspect ratio (1.78:1), whereas standard television uses 4:3 aspect ratio (1.33:1). A DVD disc can store video in either standard or widescreen format. DVD players can automatically format widescreen video for display on standard televisions letterboxing or pan and scan.

Widescreen -- A wide picture format for film at 16:9 aspect ratio.

4:3 -- Standard aspect ratio used for television; one third wider than it is high (1.33:1).

16:9 -- Widescreen aspect ratio used for film; almost twice as wide as it is high (1.78:1).

Letterbox -- A technique used to display a widescreen video image (with a 16:9 aspect ratio) on a standard television display (with a 4:3 aspect ratio). The widescreen image fills the width of the screen, with black bars above and below it.

Anamorphic -- A method of storing widescreen video on DVDs. The original 16:9 widescreen image is squeezed horizontally and stored on disc in the standard 4:3 video resolution or typically letterboxed on a standard television monitor, or cropped to 4:3 aspect ratio. The DVD player then stretches it back out to the original aspect ratio for display, either to a widescreen monitor or typically letterboxed on a standard television monitor.

Pan and Scan -- A technique used to crop a widescreen film (with a 16:9 aspect ratio) to store and display it at standard 4:3 aspect ratio. Instead of just cutting off the two sides of the widescreen image, an operator pans a 4:3 window within the full widescreen frame in order to show the most important speaker or action.

Split-screen -- A divided display that shows two clips, or portions of clips, side by side.

Over scan -- The outer edges of a video image that are typically cut off by consumer television sets in order to ensure that the image fills the entire display.

Safe area -- Also known as the safe zone. Margins left around the edge of the image. Used when working with material intended for display on television. Safe margins keep titles from bleeding off the screen.

VIDEO FUNDAMENTALS:

Analog media -- Audio sources, such as audio cassettes and microphones, and video sources, such as VHS and 8mm VCRs and camcorders, that must be digitized and converted into digital format for processing by a computer. Newer digital formats such as DV and DVD have higher resolution and quality than older consumer formats like VHS, and also do not degrade in quality when they are copied from one generation to the next.

Digital media -- Audio and video sources such as audio CD, DV, miniDV, Digital8 camcorders, and DVD that store the audio and video in digital format. As a result, the data can be imported and processed directly by a computer, and copied without any loss from one generation to the next.

VTR -- Video Tape Recorder. Also called VCR (Video Cassette Recorder).

Composite video -- A video signal that combines the brightness (luminance or luma) and the color (chrominance or chroma) video information into one signal. Because the signal is not modulated, composite video provides higher quality than RF video. Requires a separate audio signal and connector. Also called Baseband video.

Component video -- A video signal that separates the video signal into three separate signals (and three separate wires) to avoid any quality loss from mixing signals. The components can be RGB (red, green, and blue); luma (Y) and two chroma signals, such as Y, Y-R, Y-B; or other formats including YUV, YCbCr, or Y Pr Pb. Requires a separate audio signal and connector.

Luminance -- The intensity or brightness of a video signal, usually represented by the letter Y. Video signals are split into separate luma and chroma (color) components for higher-quality and more efficient transmission and encoding. In YUV color format, for example, the color information stored in U and V (the color difference signals).

Chrominance -- The color of a video signal. Video signals are split into separate luma and chroma (color) components for higher-quality and more efficient transmission and encoding. The chroma signal is typically split into two components or color difference signals, such as YUV format.

RGB -- Acronym for Red, Green, Blue. Full-color video signal format, consisting of three elements.

YUV -- Full-color video signal format, consisting of three elements: Y (luminance), and U and V (chrominance).  

Field -- For interlaced video sources, a full frame is constructed from alternating odd and even lines from two video fields captured at slightly different times..

Frames -- The individual video images that make up a moving sequence. Video formats and individual clips are typically described in terms of the resolution of the individual frames, and the frame rate at which they are played.

Frame rate -- Playback speed as determined in frames per second (fps).

Progressive video -- Video consisting of complete frames, not interlaced fields. Each individual frame is a coherent image captured by the camera at a single moment in time.

Progressive scan -- Video display in which the entire screen in refreshed (redrawn) at once. Typically used for computer monitors and high-end video systems.

Interlaced video -- A technique used for television video formats, such as NTSC and PAL, in which each full frame of video actually consists of alternating lines taken from two separate fields captured at slightly different times. The two fields are then interlaced or interleaved into the alternating odd and even lines of the full video frame. When displayed on television equipment, the alternating fields are displayed in sequence, depending on the field dominance of the source material.

De-interlace -- To process interlaced television video, in which each frame contains alternating pairs of lines from two separate fields captured at slightly different times. The motion between fields can cause visible tearing when displayed on a computer monitor. Deinterlacing uses every other line from one field and interpolates new in-between lines without tearing.

2-3 / 3-2 pull down -- Process used to convert material from film to interlaced NTSC display rates, from 24 to 30 frames per second. This is done by duplicating fields, 2 from one frame and then 3 from the next frame (or 3 and then 2). Both terms are often used interchangeably to describe the effect.

Inverse telecine -- The process used to reverse the effect of 3-2 pulldown, removing the extra fields inserted to stretch 24 frame per second film to 60 field per second interlaced video.

Master -- For video, the original video or audio source, or final video production with analog media, the first tape you create from your PC video file, also known as the first-generation tape. The master tape is a high-quality source to which you should return whenever you want to make more copies. Although you could use the file on your hard drive as a master, you won't want to keep that file forever because it takes up so much storage space. If you're using analog video, however, the PC file is your master source and first generation; the first physical tape you record is considered to be a second-generation tape.

Talking head -- A clip that shows just the head and shoulders of a person who is talking. This tight focus is often used in interview situations where the background is not as important as the talking subject. It is also convenient in a movie destined for the Web because the small amount of movement in a talking-head shot compresses well for the Internet.

Freeze frame -- A technique in which a particular frame of video is held onscreen. Sometimes the audio portion of the scene continues playing.

Still frame -- A single image or single frame of a video clip.

Leader -- The beginning of the physical tape on a videocassette or extra material before the beginning of a clip. A tape leader is a strip of nonrecording material that connects the actual recording tape to the spindle on the cassette. Most cassette tapes have about five seconds of leader before the actual recording media portion of the tape begins.

Pre-roll -- To start a tape spinning up to speed before beginning playback or capture to ensure that the operation is synchronized properly.

Stripe -- To prepare a new videotape for a recording by prerecording a consistent timecode over the full length of the tape.

Dub -- To duplicate or make a copy of a production, traditionally from one tape (usually a master tape) to another tape.

Timecode -- An exact time used to identify a specific frame in a clip or production. Measured in hours, minutes, seconds, and frames.

Synchronize -- To keep two sequences playing at the same rate (in sync). A slide show or a series of video clips can be synced to the beat on an audio track. A talking-head video needs to maintain lip-sync, so that the audio matches the mouth movements of the speaker.

AUDIO FUNDAMENTALS:

Mono -- Monophonic audio - a single channel of audio.

Stereo -- Two-channel audio, with left and right channels.

Narration -- A voice that explains what is happening on a video. Voiceover narration can add tremendous value to a video by explaining the situation being shown to viewers.

Sample rate -- The rate at which samples of a continuous signal, such as music or a sound, are captured into a digital representation of the original signal. A higher audio sampling rate, with more samples per second, creates a more accurate representation of the original sound.

Hz -- Hertz. A measurement used for audio sampling rate, as in the number of audio samples per second.

Mic. -- Microphone audio input.

Line level -- An analog audio connection intended for connecting interconnecting audio equipment, and without the amplification required to connect to speakers.

ANALOG VIDEO FORMATS:

NTSC -- A television video format used in the United States and elsewhere. Displayed 525 lines of resolution at 60 fields per second, 30 frames per second (actually a fractional value near 29.97). Named for the National Television Standards Committee.

PAL --Phase Alternation Line. A television video format used in Europe and elsewhere. Displayed with 625 lines of resolution at 50 fields per second, 25 frames per second.

NTSC safe colors -- Colors that are inside the safe region for NTSC television video. Title colors that are outside this range can display badly and bleed on NTSC televisions.

RF video -- Acronym for Radio Frequency. A composite video signal that has been modulated with audio onto a high-frequency radio wave that could be transmitted from an antenna. Typically connected to the antenna input of a TV receiver, and received on channel 3 or 4. The simplest and lowest-quality video signal connection.

S-Video -- A video signal that transmits the brightness (luminance or luma) and the color (chrominance or chroma) information separately. Actually uses a single cable, but with two wires in the cable. Because the luma and chroma are separate, S-Video provides higher quality than composite video. Requires a separate audio signal and connector. Also called Y/C, or sometimes (incorrectly) called S-VHS.

F connector -- A video connector with a thin center wire typically used for antenna connections and RF signals.

RCA connector --  A connector with a single central plug, commonly used for audio signals and composite and component video. Also called a phono connector

S-Video connector -- A specialized connector used for S-Video signals. Contains multiple pins for the separate video components.

BNC connector -- A twist-on connector commonly used for higher-end video systems. Used for both analog and digital signals.

DIGITAL VIDEO FUNDAMENTALS:

Pixel -- The individual picture elements, or "dots" of color, that are arranged in a two-dimensional array to define a digital image or video frame. The dimensions or resolution of an image are described in terms of the horizontal and vertical pixel count.

Resolution -- The dimensions of an image, in pixels, typically expressed as the number of horizontal pixels across and the number of vertical pixels down.

Transcode -- To convert from one compression format to another (that is, from DV video from a camcorder to MPEG-2 for DVD). Preferably done intelligently to minimize loss of quality from repeated compression, and not requiring fully decompressing the input and then recompressing to the output.

Compress -- To reduce the size of audio or video data through the use of a compression scheme. Also called encode.

Decompress -- To process a compressed bitstream and recover the original data (if lossless compression), or an approximation of the original (if lossy compression). Also called decode.

Lossless -- Any compression scheme, especially for audio and video data, that uses a nondestructive method that retains all the original information, and therefore does not degrade sound or video quality.

Lossy -- Any compression scheme, especially for audio and video data, that removes some of the original information in order to significantly reduce the size of the compressed data. Lossy image and audio compression schemes such as JPEG and MP3 try to eliminate information in subtle ways so that the change is barely perceptible, and sound or video quality is not seriously degraded.

Perceptual compression -- A compression technique that takes advantage of knowledge of how humans perceive; that is, by eliminating visual detail that the eye cannot easily see or audio frequencies that the ear cannot easily hear.

Compressor -- Program by which files are compressed. A compressor that also decompresses files (returns them to their original state) is called a codec.

Codec -- A video or audio compression component that can both compress and decompress (encode and decode) files. Media formats and players, such as Windows Media, RealMedia, and QuickTime have a selection of codecs built in, and can add additional codecs to support new file formats.

DIGITAL VIDEO FORMATS:

DV -- A Digital Video tape and compression format for consumer and professional video equipment. The DV compression format is used for DV and Digital-8 camcorders. DV format video and audio can be captured using a FireWire / IEEE 1394 interface and then saved and edited in a video editor. The consumer tape format is more accurately called mini-DV.

FireWire -- A digital data interface standard that provides a high-speed Plug-and-Play interface for personal computers. Used for connecting DV camcorders to computers, as well as to hard disk drives and DVD drives. Supports up to 480 Mbps data rate. Also known as IEEE 1394 and Sony iLink.

FireWire connector -- A roughly rectangular, hot-pluggable connector used for FireWire/IEEE 1394 digital connections, especially digital video signals such as from DV camcorders. The connectors can vary in size: full-size (6-pin) for connecting to a computer or hub, and smaller (4-pin) for connecting to equipment such as DV camcorders.

USB (Universal Serial Bus) -- A digital data interface standard providing a Plug-and-Play interface for personal computers. Typically used for lower-speed peripherals such as mice, keyboards, printers, and scanners. Also used for interfacing to digital cameras. The existing USB 1 standard provides up to 12Mbps (million bits per second) data rate. The new USB 2 standard supports up to 480Mbps data rate.

AVI -- Acronym for Audio Video Interleave. The old multimedia file format used under Windows for interleaved video and audio streams.

Video for Windows -- The media file format used with Microsoft Windows (.AVI). Supports many different video and audio compression formats (codecs).

Windows Media -- The multimedia platform built into Microsoft Windows, and a series of formats for storing and transmitting video and audio. Uses ASF, WMA, and WMF file types.

Windows Media Video (WMV) -- The Microsoft Windows Media format for compressed video and audio files on CD and DVD discs.

QuickTime -- Multiplatform, multimedia Movie file format from Apple Computers (.MOV).

RealMedia -- Multiplatform, multimedia Web streaming file format from Real Networks (.RM, .RAM).

Streaming media -- Internet video and/or audio clips that can play directly over the Internet, without needing to be downloaded first onto a computer. Used to view and hear broadcasts, and to interactively play and seek in stored clips.

Progressive download -- A technique for downloading Internet video and/or audio clips so that they can be viewed at the same time that they are being transferred to your computer. This provides some of the benefits of streaming media without requiring a special streaming server.

MPEG -- A family of popular multimedia file formats and associated compression schemes defined by the Moving Pictures Expert Group. MPEG-1 video was designed for use on CD-ROMs and provides picture quality somewhat comparable to VHS. MPEG-2 video was designed for consumer video and is used on DVD, and can provide high-quality full-screen full-rate video with smaller file sizes. MPEG-4 video is designed for a broad range of multimedia applications, and is used for web and wireless streaming video. MP3 is a commonly-used audio compression format, especially for web downloads and portable music players.

MPEG-1 -- An older digital video compression format developed in the early 1990s by the Moving Picture Experts Group. MPEG-1 video was designed for lower-resolution video played from CD-ROM and provides picture quality somewhat comparable to VHS (typically 352x240 resolution). Used for Video CD discs.

MPEG-2 -- A TV-quality digital video compression format developed in the mid-1990s by the Moving Picture Experts Group. MPEG-2 video provides high-quality full-screen full-rate video (720x480 resolution for NTSC) with smaller file sizes than MPEG-1. Used for DVD discs, and also scales to high-definition resolution and bitrates.

MPEG-4 -- A digital multimedia compression format developed in the late 1990s by the Moving Picture Experts Group, that includes video, audio, and interactivity. MPEG-4 video is designed for interactive multimedia across networks, and works well for web and wireless streaming video.

CBR -- Acronym for Constant Bit Rate. A compression scheme in which each unit of input material is always compressed to the same output size. For MPEG-2 video, for example, this means that the compressed data always has the same data rate (that is, bytes per second), even when the input material is very easy to encode.

VBR -- Acronym for Variable Bit Rate. A compression scheme in which each unit of input material can be compressed to different sizes. For MPEG-2 video, for example, this means that "easier" sequences (that is, with no motion) can compress to very small sizes, whereas "hard" sequences (with lots of motion and scene cuts) can compress to much larger sizes. VBR compression can take better advantage of the overall available bandwidth of a video transmission or DVD player by allocating the available bits intelligently to the difficult parts of a sequence.

HDV -- HD on DV - MPEG-2 video in HD resolution
AVCHD -- MPEG-4 AVC in HD

DIGITAL AUDIO FORMATS:

AIFF -- Acronym for Audio Interchange File Format; Macintosh audio file format. Can be used for uncompressed and compressed data.

MP3 -- An audio file format, especially popular for downloading songs from the web and for storing music in and portable music players. Named for Moving Picture Experts Group (MPEG) 1, Layer 3. Uses lossy compression to significantly reduce file size, but often with little perceptible loss in sound quality. Used to store large song collections on hard disc, download audio to portable audio players, and save multiple hours of music to CD. Some consumer audio players and set-top DVD players can play MP3 audio files stored on CD-R/RW discs.

WAV -- The uncompressed Wave audio file format used with Microsoft Windows.

Windows Media Audio (WMA) -- The Microsoft Windows Media native audio file format. Used for compressing, storing, and organizing CDs and downloaded audio in albums on disk. Also used to download audio to portable audio players. Some consumer audio players and set-top DVD players can play WMA audio files stored on CD-R/RW discs.

DIGITAL DATA RATES:

Bandwidth -- The amount and rate of data that can be processed or transmitted by a given device. An analog modem has very little bandwidth compared to a high-speed cable modem, for instance, so the former cannot download video from the Internet nearly as quickly as the latter.

Data rate -- The speed at which data is transferred, as in bytes per second. Also called bit rate. For example, the speed to download or stream a video file over the Internet, or the speed at which the file must play from a hard disk. When you create a video or audio file, you can specify the target bit rate at which the file will be played. Also called bit rate.

Bitstream -- A collection of data, as in video or audio data compressed to a file or transmitted between devices.

Bit -- A binary digit. The fundamental element of computer logic and numbers. Represents one of two values: zero or one, off or on, false or true.

Byte -- A data element containing eight bits, or 256 distinct values. Commonly used to store a single text character. Computer data transfer rates are traditionally measured in bits, as in Mb for Megabits (millions of bits, with a lower-case "b"); whereas computer data storage is traditionally measured in bytes, as in MB, for megabytes (millions of bytes, with an upper-case "B").

MB -- Megabytes (millions of bytes). In computer use, a megabyte actually represents the closest binary power of 2 to a million, or 1024 squared.

GB -- Gigabytes (billions of bytes). In computer use, a gigabyte actually represents the closest binary power of 2 to a billion, or 1024 cubed. In general use in advertising DVD disc capacity, however, the number of "GB" is actually used to specify a different value, a billion decimal.

VIDEO EDITING - Clips and Tracks:

Single-track editing -- A style of editing in which the Timeline is condensed to a single row per track.

A/B editing -- A style of video editing in which you edit together clips in pairs - A and B - typically with a transition from one to the next. This style is useful for assembling a program with simple drag-and-drop convenience.

Duration -- A length of time. For a clip, the length of time that it will play, determined by its overall length. Or if the clip has been trimmed, the difference in time between its In point and Out point.

Crop -- To make an image physically smaller by trimming away one or more edges. This reduces the dimensions of the image, and reduces the size of the computer file.

Trim -- To cut out a segment of a clip by removing frames from the beginning and/or end. To adjust the In or Out points of a clip to identify the portion to be used in the final production.

Marker -- A placeholder used to mark a specific timecode in a sequence. Use to keep track of changes, events, or synchronization points in a longer sequence. You can use the In and Out point markers to mark a clip to be captured from a source tape, to mark part of a clip to be trimmed, or to mark a portion of the Timeline to be played.

In point -- A placeholder used to mark a specific timecode as the starting point of a segment in a longer sequence. You can use In and Out points to mark a clip to be captured from a source tape, to mark part of a clip to be trimmed, or to mark a portion of the Timeline to be played.

Out point -- A placeholder used to mark a specific timecode as the end point of a segment in a longer sequence. You can use In and Out points to mark a clip to be captured from a source tape, to mark part of a clip to be trimmed, or to mark a portion of the Timeline to be played.

Split edit -- To adjust the video and audio portions of a clip separately so that they start or end at different times. Used for audio cross-fading so that the audio can lead in or fade out independently from the cut in the video.

J-cut -- A split edit in which the Pin point of a clip is adjusted to overlap the preceding clip so that the audio portion of the later clip starts playing before its video as a lead-in to the visual cut. Also called an audio lead.

L-cut -- A split edit in which the audio Out point of a clip is extended beyond the video Out point, so that the audio cuts after the video and continues playing over the beginning of the next clip.

Four-point edit -- A method of setting In and Out points to precisely control where and how frames are inserted into a Timeline. In a four-point edit, you set all four In and Out markers, and the editor displays a warning dialog if the durations do not match.

Three-point edit -- A method of setting In and Out points to precisely control where and how frames are inserted into a Timeline. In a three-point edit, you set any three such markers, and the software determines the fourth to match the specified duration.

Ripple edit -- A method of editing in the Timeline so that when new material is inserted, or existing material is deleted, other material is adjusted to fit. In a ripple edit, the change ripples through the rest of the material, as the existing clips slide apart to make room for the new material, or slide together to fill a gap.

Rolling edit -- A method of editing in the Timeline by adjusting and trimming two adjacent clips. When you roll the cut point between the adjacent clips, the durations of the two clips are adjusted to keep the overall program duration unchanged. The Out point of the first clip is changed in tandem with the In point of the second clip so that, as one increases in duration, the other decreases to match it.

Slide edit -- A method of editing in the Timeline by moving a clip and trimming neighboring clips to adjust to the change. When you slide a clip earlier or later in the program, the neighboring clips are trimmed accordingly by changing their In and Out points so that the duration of the overall program remains unchanged.

Slip edit --  A method of editing in the Timeline by changing the trim points in a clip. When you slip the trim points earlier or later in a clip, the In and Out points are adjusted correspondingly so that the duration of the clip is unchanged. A slip edit also does not affect the rest of the program on the Timeline.

VIDEO COMPOSITING:

Composite - superimpose -- To layer multiple tracks onto the Timeline. To composite portions of multiple clips into the final production by overlaying clips with transparent regions to allow the underlying tracks to show through.

Superimpose track -- In video editing, the Video 2 track and above, which can include titles, logos, and other material to be overlaid on the bottom Video 1 track.

Opaque -- Regions of a superimposed image that are solid (not transparent), and therefore cover over the underlying image.

Transparent -- Regions of a superimposed image that are invisible, and therefore show through to the underlying image, as used for logo overlays and blue-screen effects. May be defined using a key color or alpha mask. Technically, overlays also can be translucent, and blend portions of the two images.

Key -- To specify a region of an image or video clip to be used as a mask for transparency. Used to make part of the scene transparent or semitransparent, and then composite it with other superimposed images or video tracks. The region can be specified using features such as color (a color key) or intensity, or with a separate alpha mask or image matte.

Mask - An image which defines areas in a frame to be used as a transparency key or matte. Each pixel in the mask image indicates the degree of transparency to be used for the corresponding pixel position in each frame.

Matte -- An image mask used to define the transparent areas of each frame to be used in superimposing multiple clips.

Alpha channel -- Extra information stored with an image to define  transparent areas used for keying and superimpositions. Also called an alpha mask. Sometimes present in files prepared using a tool such as Adobe Photoshop or Illustrator.

Blue screen -- A specially colored backdrop (typically blue or green) that can be matched with a color key and made transparent so that it can be replaced with another video layer. For example, you can cut out a subject from the blue screen background and composite it into another scene.

Garbage matte -- A mask used in a keying operation to remove a region of a frame that contains unwanted objects.

Watermark -- A small, semitransparent graphic that identifies a scene or speaker. Many TV broadcasts use a watermark to let you know what channel you're watching.

AUDIO EDITING AND EFFECTS:

Rip -- To extract data from a removable disc. Typically, to copy songs from a prerecorded CD-Audio disc to hard disc in order to organize a collection, and play and burn personalized playlists.

Playlist -- Typically, a list of songs to be played in a specified order. Used to organize collections to download to a portable audio player or burn to a CD.

Sweeten -- To use audio effects to enhance and manipulate the audio sound.

Audio waveform -- A graphical representation of an audio clip, helping to visualize the sound in the clip by showing the signal levels. Editors can show a waveform in audio tracks in the Timeline and in a separate Clip window when you open an audio clip.

Gang -- To adjust multiple tracks at the same time, as in the Audio Mixer window.

VU meter -- An audio mixer's display of audio levels for each track.

Gain -- Overall audio output volume. Increase gain to amplify a clip, or decrease gain to attenuate a clip, making it quieter.

Amplify -- Increase the audio volume.

Attenuate -- To reduce audio strength or volume.

Dynamic range -- The difference between the softest and loudest sounds. Decrease to compress the range and reduce noise, or expand to emphasize volume differences.

Balance -- To distribute two channels of a stereo clip between the left and right channels.

Pan -- To move the apparent location of a mono audio track to position it between the left and right stereo channels. With stereo clips, you adjust the balance between the two channels.

Delay -- An audio effect that provides an echo of a sound after a specified time period.

Equalize -- To adjust the tonal quality of an audio clip. As with graphic equalizers found in home or auto audio equipment, an equalize effect can to boost or cut the original signal at different frequency bands.

Reverb -- An audio effect that simulates the ambience of a room of a specific size and with different sound-absorbent properties.

Band pass effects -- Audio effects designed to remove specific frequencies from an audio clip (manifested as hisses, whines, and hums).