Chapter 12 Sound and Video Recording. Motion Picture Film Recording Today, most television programs...

Chapter 12Sound and Video Recording

Motion Picture Film Recording

• Today, most television programs are shot, edited, and saved to tape/film/disk before being transmitted and delivered to a mass audience.

• In the early days of broadcasting, however, programs were produced and transmitted simultaneously – a “live” production.

Early TV

• Like many programs in this era, the popular children’s program Howdy Doody was produced and transmitted “Live,” in real time.

Kinescope

Prior to 1956, the kinescope was the only system available for recording a “live” TV production.

Magnetic Recording

With an open-reel recorder an analog audio signal is recorded to the surface of ¼” wide magnetic tape.

Helical Scanning

Helical scanning records picture data diagonally across the width of the tape.

VideotapeThe recording surface of a videotape is divided into linear regions called tracks. Most tape-based systems support four tracks – one for video, two for audio, and one for synchronization data.

Professional Videotape

Analog Tape Formats

• Sony U-Matic ¾” and U-Matic SP

• Sony Betacam and Betacam SP

• Panasonic M and MII

Recording Formats

Recording formats have become progressively smaller over time

•U-matic tape (top)

•MiniDV (middle)

•SD Memory Card (bottom)

Field RecordingPrior to 1971, all field recording was done with film cameras. This meant a time delay for film processing.

Portable videotape recording led the way for electronic newsgathering (ENG).

Remember VHS?

• VHS, Betacam and Hi-8 are analog tape formats

• MiniDV is a digital tape format

Composite vs. Component Video

Three components of video: brightness, hue, and saturation.

Tape isn’t interchangeable

• Tape formats are not generally interchangeable.

• A videotape can can only be used in a compatible VTR.

Digital Tape Formats

Eliminated generational loss during editing or duplication

•D1 and D2

•Panasonic: D3 and D5

•Sony: Digital Betacam and Betacam SX

Large and Small Format Camcorders

• Large format – easier to use for shoulder-mounted camera work, designed for professional use

• Small format – less expensive, fewer professional controls, prosumer level quality

High-Definition Tape Formats

• Sony: HDCAM and MPEG IMX

• Panasonic: D5HD

HDTV

HD signals require more bandwidth for recording

DV Formats

• MiniDV

• Panasonic DVCPRO and DVCPRO HD

• Sony DVCAM

• HDV

DV – the Blue Book Standard

DV was a recipe book that manufacturers could use for designing a variety of recording formats for different market segments.

Video Compression

Video compression has two goals:

1) Reduce file size of an image by eliminating or rewriting as much of the redundant information as possible

2) Preserve the visible quality of an image

Video Compression (continued)

Two most commonly used methods of compression used today:

1) Intraframe (or I-frame) compression• Eliminates spatial redundancies within a

video frame

2) Interframe compression• Exploits both spatial and temporal

redundancies• All frames in the video are intracoded to

eliminate spatial redundancies

Spatial redundancy (single frame)

Spatial redundancy occurs within a single video frame

Temporal redundancy (multiple frames across time)

Temporal redundancy occurs in time over a sequence of motion picture frames

Apple Compressor 4

You can use video compression tools to encode your video in any number of common distribution formats. Apple Compressor 4 (pictured) is a powerful encoder, but it only runs on a Mac.

MPEG Streamclip (cross-platform)

MPEG Streamclip is a free cross-platform video encoder and can be used to transcode digital video files.

Multiple Platforms• Your distribution preferences affect how you

encode your video

• You may want to produce a DVD or Blu-Ray disc, upload to YouTube or Vimeo, or save your video to an iPad or Android tablet

• Your video must be encoded in a format that’s appropriate for a given distribution channel

• Editors often find themselves creating multiple versions of a single project for different channels or end-users

Consumer Formats

• It was once not possible to record a TV show off the air

• VHS was the most popular consumer tape format for off-air recording and distribution of feature films

• Home recording made possible time-shifting

• Optical disc (DVD & BluRay) was designed to replace VHS

File-Base Recording

Open standards – publically released but has specific conditions and applications for its use

• Typically drafted & approved by technical experts and stakeholders – working groups

• NGO / ISO / IEC

Proprietary standards – crafted by a single manufacturer, a small group of companies, or a large consortium of manufacturers with a shared stake in the deployment of a common format

A plethora of video formats to choose from…

…don’t worry. You won’t use them all.

Solid-state Recording Formats

Three solid-state, nonlinear, random access formats:

• Sony Professional Disc

• Sony SxS

• Panasonic P2

Propriety Card Formats

• Designed for professional users

• More robust and reliable than off-the-shelf SD cards

• More expensive and often out of the range for low-budget producers

SxS

Sony introduced a series of professional cameras that record video to an SxS memory card.

AVCHD

• An open standard for recording HD video that’s compatible with inexpensive flash memory card formats like SD, SDHC, and Compact Flash

• Supported by many professional editing programs

• Flash memory cards have increased in size and dropped in price

• Supported by a wide range of consumer electronic equipment

AVCHD File Directory Structure

It’s crucial to keep the file structure intact – any discrepancy might mean your editing software won’t recognize the video files