doc video editing

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Universit of Technolo

Digital Video Editing


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Aims for today

Standards

Image Resolution

Aspect Ratios

Pixel Aspect Ratio

Interlace and Progressive Scan Modes 126

Frame Rate

Frame size

Video standards

Converting between 16:9 to 4:3, 4:3 to 16:9 (zooming,

stretch, letterbox..)


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Tutorial 3


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Standards

A standard is a set of protocols or rules that define how asystem operates.Standards provide a coherent platform from whichinformation can be created, extracted, and exchanged.Without these protocols, there would be no consistencyin the handling of information.

Do you know examples of standards

Television is the conversion of light to electrical energy.

The process by which this conversion takes place isreferred to as a television standardor system.

Standards are necessary so that video signals can becreated and interpreted by each piece of videoequipment.NTSC is one example of a video standard. Otherworld

standards include PAL and SECAM


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Video standards

3 major video standards

NTSC

PAL

SECAM


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NTSC

National Television Standard Committee

Best known in America

Since it began as an analog formatIts size is measured in horizontal scan lines

There 525 scanlines to a frame of NTSC video

It displays at 30frames per second

Used in north and central America, the

philipines, south Korea,Taiwan


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PAL:Phase Alternation by Line (PAL) format

Has higher resolution

625 scanlines

Run at 25 fpsUsed in Europe, Scandinavia part of asia the

pacific and south Africa

PAL M : A version of PALUsed in Brazil only

525 sl

30 fps

Uses PAL color Palette


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SECAM:Systeme Couleur Avec Memoire

formatUsed in France, Russia, Middle East andNorth Africa.

625 Scanlines25 fps

PAL color Palette

We can consider each of these standard

format to be IMCOMPATIBLE with eachother.


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Conclusion

ShootingNTSC VideoShooting

NTSC Video


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Which videoshoud I

choose ?

Which videoshoud Ichoose ?

Dependsupon where

your video is

going to beseen !!

More reading:

http://www.ee.surrey.ac.uk/Contrib/WorldTV/why.html


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Importing Images in Premiere Pro

5 guidelines that should be followed forimporting still images in APP.

Make sure that the file format is supported by theoperating system you plan to use.

Set the pixel dimensions to the resolution you will usein Adobe Premiere Pro. If you plan to scale the image

over time, set image dimensions that provide enoughdetail at the largest size the image has in the project.

If final output will be shown on standard television

screens, avoid using thin horizontal lines (such as 1-pixel lines) for images or text. These may flicker as a

result of interlacing.


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For best results, create files with a frame size at leastas large as the frame size of the project so that youdont have to scale up the image in Adobe PremierePro.

Crop the parts of the image that you dont want to bevisible in Adobe Premiere Pro.

If you want to designate areas as transparent, create

an alpha channel or use the transparency tools inapplications such as Photoshop or Illustrator.


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For best results, create files with a frame size at leastas large as the frame size of the project so that youdont have to scale up the image in Adobe PremierePro.

Crop the parts of the image that you dont want to bevisible in Adobe Premiere Pro.

If you want to designate areas as transparent, create

an alpha channel or use the transparency tools inapplications such as Photoshop or Illustrator.


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Premiere Pro and Illustrator Files

Adobe Premiere Pro converts path-basedIllustrator art into the pixel-based image

format used by Adobe Premiere Pro, aprocess known as rasterization.

Adobe Premiere Pro also converts all

empty areas into an alpha channel, so thatempty areas become transparent.


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Thumbnail for a video in the project panel

Select the clip in a Project panel.

Press the Play button or drag the play slider on the

thumbnail viewer in the upper left corner of the Projectpanel until the frame you want is displayed.

Click the Set Poster Frame button


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Progressive vs. Interlaced Video

Videos is made up of a series of horizontallines called scanlines

When you display all these horizontal linesequentially from top to bottom.That is : 1, 2 , 3 , 4 , .end

This is called a progressive scan.All Computers monitors use Progressivescan. They start at the top of the image

and they go to the bottom of the imagewhen working with CRT monitor.


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In the early days monitors could not display allthe scanlines from top to bottom.

Instead they created two separate fields:One field held odd number lines (1 3 5 7) Lower fields

The other one held the even number lines (2 4 6 810).Upper Fields

First odd number field is displayed then the evennumber field.

By weaving these two fields together theycreated a single frame of video.

Computer use Progressive while TV useInterlace


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Read More

http://www.avdeals.com/classroom/Proscanex

plained.htm


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Frames rates

There are generally 3 FPSFILM: 24 FPS

PAL:25 FPSNTSC:30 FPS

Of the three only PAL actually run at 25 fpsThe others can deviate a little

Film in theater 24 fpsWhen it is digitized it becomes 23.98 fps

NTSC video: Theoretically 30 fps butactually 29.97 fps


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Frames rates

A frame is a complete image composedof two fields.

A field is all the even number lines andthe odd number lines


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Video formats

Video standardsFrame rates.Progressive ..interlaced

Can it getmore

complicated

?

Can it getmore

complicated

?

Yes itcan!!!!!


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Video formats

There are actually three principle videoformats.

The low end is DVThe mid range is SD

The High range is HD

DV=Digital Video

DV=Digital Video

SD=StandardDefinition

Video

SD=StandardDefinition

Video

HD=

HighDefinition

Video

HD=

HighDefinition

Video


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Video formats

DV

Mini DV

DVCPRO-25

DVCAM

If you take same

Camera

Same Lighting

Same lense

And simultaneously record in the above three

format the image quality will be identical acrossall three.


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Video formats

SD

Older than DV and encompasses both analog

and digital formatsDVCPRO-50 (digital)

BETACAM SX (digital)

BETACAM SP(analog)

DIGIBETACAM (digital)


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Video formats

HD

Also have a wide variety of format but lets

stick to the following:HDV- new latest (It is the high definition versionof DV)

DVCPRO-HD (100)

HD


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Image size

Lets get into the differences of DV/SD/HDvideo.

All are fixed in size, i.e. they are bitmapvideo..meaning their resolution are fixed atthe moment they are created.

If I take an image whether DV or HD andproject it on a 20 inch monitor and then toan 80 foot screen there is no additionalinformation.

DV f SD


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Image size

DV NTSC = 720 x 480

DV PAL = 720 x 526

SDNTSC 720 x 486

PAL 720 x 576

Did younoticed

somethinghere ?

Did younoticed

something

here ?

Yes I

did !!!

DV came after SD .

SD NTSC =720 x 486

BUT DV NTSC =720 x 480

WHY ??!

DV came after SD .

SD NTSC =720 x 486

BUT DV NTSC =720 x 480

WHY ??!

Video Compression requires with 4 x 4 pixel squares !!!


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Image size

HD : High Definition

Is different as it gives us more pixels to play

with.It comes in two flavour

Both interlaced and progressive formats

HD 480I & p (Smallest size)Used everyday for Broadcast television

HD 720I & p (720 refers to number ofvertical lines of information)


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Image size

HD 720I & p

1280 x 720

HD 1080i & p1920 x 1080

1920 pixel across

1080 pixel high

All HD format are 16:9

16 unit wide by 9 units high


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Aspect Ratio

A number which describes the relationshipof the height of a picture to the width of a

picture.Generally the height is describe as thenumber 1 and the width describe how

much longer than 1 unit high the picture iswide.

Two principle aspect ratio are 4 by 3 and16 x 9.

A R i


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Aspect Ratio

It comes down to the competition between filmand television.To compete with TV, Film started changing

aspect ratio to provide a different viewingexperience.TV invented with a 4 :3 aspect ratio.

Pre 1950s movies (1.33:1)

Film wanted to give a look that cannot berepresented on television.Disney cartoons came with 1.66:1 (about 66 %

wider than tall)Movies today: 1.78:1 , ie 16:9

Why ?Why ?

C i B A R i


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Converting Between Aspect Ratios

The problem of converting pictures between

different formats has plagued film and televisioncompanies for years. Conversions almost

always involve compromise and often annoy theend user, the film director, or both.

For example, if we take the 29x9 image above

and convert it to a narrower format, we will haveto lose quite a large part of the picture. The bluelines show where the picture will be cropped at

16x9, and the red lines show a 4x3 version

C t 4 3 Vid t 16 9 Wid


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Convert 4x3 Video to 16x9 Widescreen

There are three ways to convert standard4x3 video into 16x9 widescreen:

Pillars,Stretch

and Zoom



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Pillars

In this method there is no alteration to the image.The 4x3 footage is simply placed in the centre of

the 16x9 frame, leaving vertical black bars(pillars) on each side of the frame.

This is the "pure" method as it does not distort or lose any partof the original image



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Stretch

To maximise screen use, the 4x3 image can bestretched horizontally to fill the available space

This method is popular with widescreen TV owners watching traditional 4x3

television programs. In some cases it can be surprisingly effective butviewers shy away from it due to the picture distortion. Stretching is especially

bad at making people look fat



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Zoom

The third method is to magnify the 4x3 imageuntil it fills the widescreen frame but keeps the

correct aspect ratio. This is similar to stretching,except that the image is zoomed in proportionwithout any picture distortion. Unfortunately thismeans losing parts of the image at the top and

bottom.

Convert 16x9 Video to 4x3


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Letterbox

The letterbox format is so-called because it createsblack bars above and below the image which gives

the appearance of looking through a letterbox. Thisis the "pure" method as it preserves the entirewidescreen frame. For this reason, letterboxing ispreferred by film directors and enthusiasts.



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To convert widescreen to 4x3 in a video

project, the footage is simply imported andreduced in size until it fits the 4x3 frame.

Pan and Scan


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Pan and Scan

Pan and Scan is the traditional method of

displaying widescreen content in broadcasttelevision and old VHS movies. The widescreen

image is cropped at the sides and only the mainpart of the image is shown.

Video file format


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Video file format

Media player File formatS

File formats are usually associated with MediaPlayer Software. Media Player software isessentially a collection of codecs with a playerinterface.

If a file has been saved in a proprietary mediaplayer file format it can only be played by thatmedia player. It is not always apparent from thefile format which codec is being used, only that it

can replayed by a particular media player orplug-in.

Video format:AVI


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Video format:AVI

The AVI Format

The AVI (Audio Video Interleave) format wasdeveloped by Microsoft.

The AVI format is supported by all computersrunning Windows, and by all the most popular

web browsers. It is a very common format onthe Internet, but not always possible to playon non-Windows computers.

Videos stored in the AVI format have theextension .avi.

Video format: WMV


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Video format: WMV

The Windows Media Format

The Windows Media format is developed byMicrosoft.

Windows Media is a common format on theInternet, but Windows Media movies cannot beplayed on non-Windows computer without an

extra (free) component installed. Some laterWindows Media movies cannot play at all onnon-Windows computers because no player isavailable.

Videos stored in the Windows Media formathave the extension .wmv.

Video format:MPEG


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Video format:MPEG

The MPEG Format

The MPEG (Moving Pictures Expert Group)format is the most popular format on theInternet. It is cross-platform, and supportedby all the most popular web browsers.

Videos stored in the MPEG format have theextension .mpg or .mpeg.

Video format:MOV


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Video format:MOV

The QuickTime Format

The QuickTime format is developed by

Apple.QuickTime is a common format on theInternet, but QuickTime movies cannot be

played on a Windows computer without anextra (free) component installed.

Videos stored in the QuickTime formathave the extension .mov.

Video format:rm


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Video format:rm

The RealVideo Format

The RealVideo format was developed for theInternet by Real Media.

The format allows streaming of video (on-linevideo, Internet TV) with low bandwidths.

Because of the low bandwidth priority, qualityis often reduced.

Videos stored in the RealVideo format havethe extension .rm or .ram.

CODEC


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CODEC

Stands for Coder/ Decoder

A codec is a piece of software, sometimes

called an algorithm, which is used to compress amedia file (reduce its size) and then laterdecompress it before it is played. This process isuseful for 2 primary reasons ...

1. To allow more data to be stored on a given storage device (suchas a digital video camcorder hard drive or memory card).

2. To increase the speed of transmission across a network (such asthe internet).

CODEC


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CODEC

The term "codec" is usually used inreference to audio and video mediafiles, but still image compression

methodologies, such as jpeg, canalso be called codecs. A codec maybe lossy (cause some deterioration in

quality) or lossless.Examples codecs are ....jpg (images)

.mp3 (audio)H.264 (video)

Codec/File format


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Codec/File format

codec is a piece of software (algorithm)which is used to compress a media file toa smaller size and which must be usedagain to decompressed the file for viewing.

File formats are usually associated with

Media Player Software. Media Playersoftware is essentially a collection ofcodecs with a player interface.

What codec is being used?


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What codec is being used?

If you encounter a video file with the .wmv(Windows Media) or .mov (QuickTime)extension you won't necessarily knowwhat codec its been compressed with butyou will know (version permitting) which

player software can replay it.Open the file in the player and choose theoption to look at information about the file.


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Ken Burns Effect


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when life is given to still photographs byslowly zooming in on subjects of interestand panning from one subject to another.


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THE END

ASSIGNMENT 1 or 2


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Practical


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