Audio Video System

TV STANDARDS

1. PAL

2. NTSC

3.SCEAM

1. PAL

          Phase Alternation Line (PAL) is the TV/Video Standard, developed in Germany. It used in most European countries.

          PAL video has 625 lines per frame & 50 image fields per second. The frame rate is 25 frames per seconds(fps) or 50 fields per second, with each field accounting for half the interleaved scan lines on a Televisionm Screen. used in Nepal, India and other countries.

2. NTFS  

         NTSC National Television Standards Committee is the name of TV/Video standard, dcreated by them in 1953, used in  North & Central, America, Japan, and other countries.

       NTSC video has 525 lines per frame & 60 image fields per second. The frame rate is 29.97 (30) frame per seconds(fps) or 60 field per second, with each field accounting for half the interleaved scan lines on a Television Screen.

3. SECAM

           Sequentiel Couleur &  a Memoire (SCEAM) is the TV/Video Standard. A color TV transmission system used in france & Russia and Eastern Europe.

           SCEAM video has 625 lines per frame & 50 image fields per second. The frame rate is 25 frames per second fps or 50 fields per second like PAL.

The most prominent coses behind the scenes are the:

           Producer

        Screenwriter

           Director

     Unit Production Manager

      Casting director

     Direction of photography (DP) is cinematographer

      Designers

     Assistant director

     Film and sound editors

      Music composer

The standard width of film used for a feature length motion picture is 35mm (1.38 in). An occasional largescale production appears on 70millimeter (2.76 in) film where as low budget and some experimental films are typically shot on less expensive 16millimeter (0.63 in) film.

AVI CAPTURE – VIDEO STANDARD: PAL

Capture	Codec	Resolution	F bs	Audio
Good Better	Pic. Video MJPEG codes Pic video MJPEG CODEC	352 *288 720*576	25 25	PCM 16 bit mono PCM 16 bit stereo
Best	DV video encoder	720*576	25	PCM 16 bit stereo

     MPEG CAPTURE VIDEO STANDARD:PAL

Good	MPEG1 (VCD compatible)	352*288	25	MPEG12  16 bit stereo
Better	MPEG2 (SVCD compatible)	480*576	25	MPEG12 16 bit stereo
Best	MPEG2 (DVD compatible)	720*576	25	MPEG12 16 bit stereo

AVI CAPTURE VIDEO STANDARD: NISC

Good	PCI video MJPEG codec	352*240	29.97	PCI 16 bit mono
Better	PCI video MJPEG codec	720*480	29.97	PCM 16 bit stereo
Best	DV video Encoder	720*480	29.92	PCM 16 bit stereo

MPEG CAPTURE VIDEO STANDARD: NISC

Good	MPEG1 (VCD compatible)	352*240	29.97	MPEG12 16 bit stereo
Better	MPEG2 (SVCD compatible)	480*480	29.97	MPEG12 16 bit stereo
Best	MPEG2 (DVD compatible)	720*480	29.97	MPEG12 16 bit stereo

·       Normal display (4:3 video for 4:3 display)

·       Letterboxed (16:9) video for 4:3 display or 4:3 video for widescreen.

·       Pan and scan (16:9 video for 4:3 display)

·       Widescreen (16:9 video for 16:9 display)

Films are generally shown in theaters, with motion picture projector in the rear of the theater shining the image over the heads of the theater.

     Cinerama, the first wide screen process, was introduced in theaters in 1952.

Three 35millimeter cameras and three projectors were used to record and project a single image into a larger curved screen, with the result that the images blended together to produce an illusion of vastness.

Cinemascope used a special lens called an anamorphic lens, which compressed a wide image into standard 35millimeter films, and a projector that decompressed the image, making it twice as wide as standard screen images.

    

     Panavision become the standard wide screen process using an anamorphic lens to achieve an aspect ratio of 2.35 to 1. Currently, must US films have an aspect ratio of 1.85 to 1, while most European films have an aspect ratio of 1.66 to 1. For 70millimeter films, the aspect ratio is 2.2 to 1.

FORMAT	Aspect ratio in pixel	When to use
Square pixels	1.0	Ur footage has a 640*480 or 648*486 frame size
D1/DV NISC	0.9	Ur footage has a 720*480 or 720*486 frame size and ur desired result is a 4:3 frame aspect ratio.
D1/DV NISC widescreen	1.2	Ur footage has 720*480 or 720*486 frame size and ur desired result is a 16:9 frame aspect ratio.
DV1/DV PAL	1.0666	Ur footage has 720*576 or frame size and ur desired results is 4:3 frame aspect ratio.
DV1/DV PAL widescreen	1.422	Ur footage has 720*576 frame size and ur desired result is a 16:9 frame aspect ratio.
Anamorphic 2:1	2.0	Ur footage was shot using an amorphic film lens.
D4/D16 standard	0.948	Ur footage has 1440*1024 or 2880*2048 frame size and ur desired result is 4:3 aspect ratio.
D4/D16 anamorphic	1.896	Ur footage has 1440*1024 or 2880*2048 frame size of ur desired result is 8:3 frame aspect ratio.

Pixel Aspect Ratio	Frame Aspect Ratio
Square pixel	4:3
D1/DV NISC (0.9)	6:5
D1/DV NISC widescreen (1.2)	8:5
D1/DV PAL (1.07)	64:45
D1/DV PAL widescreen (1.42)	256:135
Anamorphic 2:1 (2)	8:3
D4/D16 standard (0.95)	512:405
D4/D16 Anamorphic (1.9)	1024:405

Down convert types: use for o/ping movies.

A.  Sequeeze:

   o/p and a horizontally compressed image while maintaining its original aspect ratio.

B.   Letter Box:

     o/p and a vertically compressed image while maintaining its original aspect ratio.

C.   Edge crop:

    o/p and the central portion of the original image by cropping its right and left edges.

TV commercial or ad film production has three stage:

a.   Pre-production:

Activities like budgeting and casting.

b.   Production:

Activities like shooting under a director.

c.    Past-production:

Activities like eating dubbing and incorporation of special effects.

Basic understanding of films and tape:

 Advertising commercial can be shown in cinema halls by a projector. In this case, the commercial uses a film format.

There are three major formats in use.

70mm, 35mm and 16mm. These are different widths, which give the area of image. The edge of the films has perforation called “sprocket holes”. These holes and their spacing are specific for a particular gauge-each 16mm frame has two holes or 35mm frame has four holes. Large format gives superior image, but cast considerations rule them out. 35mm is the standard for advertising commercials for TV as well as cinema use a 35mm format. Later, the commercial is transferred from film to video-tape by using a telecine machine.

 

Aspect Ratio (width to height ratio)

Each picture has horizontal and vertical dimension. TV uses screen proportions of 4:3 or 1:33:1 (four units wide and three units high). Films for cinema have an aspect ratio of 1.65:1 in cinemascope format. The aspect ratio of the screen image in film is 2:5. If a movie is shot which is wider than 4:3 TV ratio, the picture must be modified to fit the screen. To maintain the full height, the original pictures width will have to be pruned or to maintain the width, the height must be sacrificed. There are then band stripes of black at the top and bottom. Many commercials on TV have used cinema-screen proportions and so we get images which are sandwiched between fat horizontal bandy of black.

                                       Film sound

Sound waves are magnetically recorded on films just like the audio cassette. The sound is encoded on a coat of ferrous oxide (iron salt) or similar magnetically sensitive chemical deposit.

Single system recording or commas (combined magnetic)

There should be synchronization between the action and dialogue. The synchronous sound (sync) can be recorded directly on a magnetic track along the film strip in camera at the time of shooting. This method is not employed now, since at post-production editing stage, the sync is last.

Non-sync Sound

 The door bang is heard first, and a second later the door is seen slammed shut. The singer, but he tips movements do not coincide with the words. It is called tip flap. In cameras with sound on films shooting, there is a distance between the sound head and the picture gate. The sound-head is ahead or behind the picture frame by 28 frames on 35mm. the result is a displacement by just over one second between the sound and the corresponding frame.

Separate sound recording

These days sound is recorded separately on a recorder (Nagra recorder-1/4” open-real recorder). There are two reasons for non-sync sound- stretch ability of tape, and variations in motor speed. To conjure sync, the camera and the recorder are locked together by a sync-pulse generator.

A radio sync may deliver the sync-pulse. Separate recording facilitates sync when the sound and picture are married together on a single strip of film at the editing stage.

Separate recording also improves the audio quality. 

 Non-linear editing

It is the editing process which allows us to manipulate the video and the audio. It is done entirely on computer. In essence, it is similar to manipulation of text on a word-processor. We also get the capability to move an entire segment. It gives us enhanced flexibility. The linear editing follows a strict linear order of shots. Here are can edit in any sequence. The choice of sequence in ours. In film editing this flexibility was not unknown, but in video editing it is an innovation.

Video compression

At a compression level of 1:10, the human eye is not capable recognizing of the missing out of some information. The AVID offers AVR-27 choice for technically minded is about 120-150KB per frame in PAL and definitely Betcam SP quality.

Revolutionary film editing

Conventional film editing consists in screening and blocking the footage, marking pieces of film and putting the picture together by slicing tiny snippers and running them through a viewer. The process is extremely cumbersorne and slow. The convenkonal machines of film editing-Mo viola and Steinbeck data backs to 50s and 60s. Real image, a Chennai-based company, has marketed one of the latest film editing systems in the world. It is called AVID and is a digital non -linear shots.

 POV (Point of view)

1.   ECU (extreme closeup) EG: an eye, a finger nail or a flap of a pack.

2.   VCU (very close up) EG: face of a modal using a particular brand of a soap.

3.   BCU (big close up) EG: a nail polish bottle (only the face)

4.   CU (Close up)

5.   MCU (middle close up/ chest bust shot)

6.   MS (mid shot / waist shot)

7.   ¾ shot: knee shot

8.   FLS (full length shot) EG: Remo Fernandez in Pepsi commercial

9.   LS (long shot)

10.                     XLS (extremely long shot)

Types of Shots

                                        Close up shots

  A close up is a tightly framed shot of a single person or object. In case of a person, it includes from the top of the head to the top of the shoulders.

                                     Mid shot

The mid shot extends from above the head to around the waist, and could be framed to the left or right to include a second person. A mid shot can thus become a two shot, useful in interviewing.

                                  Long shot

 The long shot includes the whole person, with his surrounding and people in the neighborhood.

Films, however, have three professional formats-70mm, 35mm and 16mm. It is easier to witch from one formal to another. Films can be converted to video format by making use of ‘telecine’ equipment.

Films and video editing are totally different. Film editing is done by wax pencil markings as per SMPTE code of the US video tape, not like the film.

It is called AVID and is a digital non-linear on-line video editing system. It is useful for both video and film.

                                     TAPE FORMAT

Tape width	Application
2 Quad	Broadcast
1 Quad	Broadcast
High Bang U-Matic 3/4	Semi- broadcast, professional
Low band U-Matic 3/4	Professional, Industrial
Betacam ½	Broadcast and Semi- broadcast
1/HS ½ and Beta	Domestic

          Comparison between FILM and VIDEO-TAPE

Point of distinction	Film	Videotape
Picture sharpness	Better than video
Color	Natural	Unnaturally exaggerated
Film stack choice	Wide as per the intensity of light EG: night scenes with film with high	Videotape is basically the same
Video cameras	Can process bright light	Can’t process bright light
Slow motion/ speed-up motion	Can be originated on film	These effects cannot be originated, and are done post production.
Movie camera	Physically robust, portable operate in adverse, whether conditions cost of developing processing and printing.	Delicate not so portable. Affected adversely
Cost	Cost of developing processing and printing.	Tape cost effective can be wiped re-used instant monitoring as the sane is being shot.
Monitoring	In the can rushes will have to be seen. To get instant monitoring a compact video camera can be mounted on the side of the movie camera.
Speed	Slow	Speedier production due to multicamera set up. Live edit possible.
Post production		Enable different optical/supper effects. Video is much superior and rules pen post-production.
Distribution	Physical	Tape can be sent on the TV station via a land-linear micro-wave link.
Commercials (ad spots)	Most are shot on RLM for better production values.	Studio programs computer graphics, Animation.
Director’s preference	Some are at home with films	Some are at home with video.

Pixels: A screen is broken up by several thousand tiny dots. One or more such dots are treated as units. Pixels is one such unit. Pixel can be single-dot on mono-chrome screen, 3-dots on color screens (R, G, B) or clusters of these dots.

                      Mega pixels

A picture’s resolution is expressed either it terms of its dimensions of it dimensions of its pixels or by its total number of pixels. The resolution could be 1160*864 pixels (read as 1160 by 864 pixels) or 1002240 (roughly 1000 thousand pixels), this resolution has touched one million, and hence it is called one mega pixels. 

                             DIGITAL PAST

     Expensive

    Few choices 

   Most low quality

   Step steep learning curve

                  DIGITAL PHOTOGRAPHY

Ø Capture

Ø Edit

Ø Output

                   DIGITAL PRESENT

Less Expensive

Software control

Camera complete pre and post images control and editing

Many more choices

Good to excellent quality

Step terming curve

Unless compulsory

                 Aperture and shutter priorities  

The amount of the light that enters the camera is controlled by the shutter and aperture, and determine the quality of the image. The shutter opens for a short while to allow the light to enter. The speed of the shutter decides the exposure and the motion of an image. To allow more light into the camera, we have to increase the aperture. This also decides the depth of the vision. Both these factors are adjustable in professional cameras. In digicams, we can keep one of these constant, and change the other. There are pre-set settings for the other.

              The tens diaphragm controls the size of the operator, or tens opening, and thus the amount of light that passes through the legs. It operates in conjunction with the shutter.    

The aperture size is measured by numerical settings called F-stops. On a traditional, manually controlled camera the F-stops are inscribed on an adjustable ring that fits around the lens typical F-stops are F/2, F/2.8, F/4, F/5.6, F/8, F/11 and F/16. The settings F/2 represent a large aperture, F/16 a small aperture with simple automatic-exposure cameras, a computer sets the aperture size, thus the aperture ring has disappeared from many of today’s lenses.

Lenses come with a rating for their maximum aperture, indicate indicating how much light can reach the film. When the lens diaphragm is wide open with single-lens-reflex cameras, the maximum aperture also influences, how-bright the images appears in the view finder-within lens types, a lens with a large maximum aperture will have a large diameter and weight more than a lens with a smaller aperture. A telephoto lenses requires a larger lens diameter and greater length to let in the same amount of light as a normal or wide-angle lens like telephoto lenses, zoom lenses are also physically.

Typing Support 

Shreeya