Movies

A movie is usually made up of a sequence of photographic images that are moved quickly past the human eye, so as to create an illusion of a moving image. Made-man pictures, often generated by a computer, can be formed into a similar sequence so as to produce animation.

Older computers aren’t ideal for movies and can only accommodate reduced-size pictures at a low frame rate. Fortunately, modern machines can handle full-motion video (FMV), providing results similar to a domestic video system, although not quite broadcast quality.

  Inside a QuickTime Application

One of the most popular movie presentation mechanisms is known as QuickTime, which can be used on both Mac OS and Windows-based computers. The applications supported by with this package in the Mac OS are QuickTime Player (or MoviePlayer in older systems), for playing movies and sounds, and Preview (or PictureViewer in older systems), for looking at still images that may be compressed using QuickTime technology.

Video Performance

When playing a movie file in QuickTime Player, the QuickTime software tries to play successive frames at the intended frame rate. If the computer can’t cope, some data may be skipped to maintain timing, which can result in jerky images or sound break-up. The actual performance is dependant on your processor speed, the drive speed, the nature of the movie (image size, colour depth and frame rate), the presence of a sound track and the type of compression.

Controlling QuickTime Player

The following shortcuts apply to QuickTime Player in the Classic Mac OS. Some are also effective in a Web browser, when using the QuickTime Plugin file, or in other applications.

EffectKeyboard Shortcut
Play forwardsReturn, Space or -⇢
Play backwards-⇠
StopReturn, Space, -., ⇠ or ⇢
Move one frame back or forwards⇠ or ⇢
Pause on or offReturn or Space
Move to start or end of sectionOption-⇠ or Option-⇢
Turn sound volume up or down⇡ or ⇣
Set sound volume to maximum or muteOption-⇡ or Option-⇣
Set sound volume beyond maximumShift-⇡

The following tricks can also be used:-

ActionEffect
Double-clicking on movie imageStarts or stops movie
Pressing Option or Shift in menuExtra options appear in Edit and File menus
Dragging progress pointerMoves to a new position in movie
Pressing Shift while dragging pointerSelects a portion of movie
Pressing Shift and resizing windowResizes image non-proportionally
Pressing Option and resizing windowResizes image in even multiples of size

The Favorites area can be used for online movies or ‘local’ movies. Items can be repositioned as required (dragging onto an existing item removes the original) and unwanted items can be dragged to the Trash. You can also drag a movie onto the desktop to create a shortcut file for later viewing. Even a text file can be dragged onto the area and played as a movie!

Inside a Movie Editing Application

A movie editing application lets you assemble video and sound material into a complete movie, for which you’ll need a computer with a FireWire port and a Digital Video (DV) camcorder.

Video Connections

First, you must get your video material from the camcorder to the computer. Simply connect the latter’s DV connection, sometimes known as an iLINK port, to a spare FireWire port on your computer. This connection conveys video and sound material to the computer, and in some instances in the other direction as well. The iMovie application can also control the transport of your camcorder via FireWire, assuming your particular type of camcorder supports this feature.

Data Formats

iMovie handles standard-quality video data as an uncompressed DV Stream, requiring at least 210 MB of disk space for every minute of recorded video. This means that you’ll need 10 GB just to record 45 minutes of material. The following table shows the data rates for the full range of DV formats:-

Format Coding Data Rate (Mbit/s)Notes
DV/DVPRODV 4:1:125Standard Quality
DVPRO50 *DV 4:2:250-
DVCPRO HD *DV-HD100High Definition (HD)
* Transfer via FireWire not supported by consumer applications, including iMovie

Handling DV data isn’t too difficult for a computer, assuming your machine has sufficient disk space, the disk isn’t fragmented and the machine has a fast processor.

Making a DVD

Your final video production can be transferred onto DVD by using Apple’s iDVD application, which is also supplied with modern Mac OS computers. It should be noted, however, that the original version of iDVD can only create DVDs of up to one hour’s duration while iDVD 2 can record up to 90 minutes. If you need to record even longer DVDs you’ll need Apple’s DVD Studio Pro, which uses variable bit rate (VBR) encoding to extend the maximum recording time to two hours.

Exporting to QuickTime

To save disk space, or to distribute your work, you can export movies as QuickTime files. Although iMovie may default to using the codec known as H.263, you’ll get better results using Sorenson Video or Sorenson Video 3 compression, especially if your material is destined for the Internet.

Movies designed for a CD-ROM should be no larger than 320 × 240 pixels, or even 240 × 180 pixels if your customers are likely to use an older CD-ROM drive. The following settings can be used in the Video section of the panel that appears under Options in the Export dialogue:-

while in the Sound part you can use something like this:-

A movie for the World Wide Web should be kept to 192 × 144 pixels, usually with the following Video settings:-

and these Sound settings:-

  Digitising Video

Video material in the form of DV data is ideal for editing. Unfortunately, movies are often supplied in alternative formats, most commonly as an analogue video or component video signal. Before editing, such material must be converted into digital form using a process known as digitising.

Your computer must have a suitable video capture card or video input adaptor, the latter connected via a FireWire port or USB port on your machine. You’ll also need suitable software to convert the signal into a QuickTime movie, MPEG movie or DV recording.

If your hardware has component video, select Component Video in the Video settings window when exporting from a QuickTime application. If your audio material is, for example, in 16-bit form, sampled at 44.1 kHz, you should also use matching settings in the Audio window. This avoids time-consuming computations for colour and bit rate conversions.

Movie Files

The following list describes some of the more common movie formats, complete with filename extensions, shown in order of preference, and Classic Mac OS type codes. Those shown with a QuickTime icon can be opened using the applications in the QuickTime package.

The most common formats found on the Mac OS are:-

  QuickTime™ Movie  .mov/.moov/.qt  MooV

This standard kind of movie file can be played by any application that supports QuickTime, assuming that the QuickTime software is installed on your computer.

Some applications add a preview image or a custom icon based on the first image. You can also add a preview in the Classic Mac OS by clicking on Create in the standard file Open dialogue. Custom icons are useful for identifying documents in the Finder or in file dialogues.

  MPEG Movie  .m2v/.mpg/.mpeg/.mpe/.mpm/.mpv  MPEG

This compressed format can be played using any suitable application.

  MPEG-4  .m4a/.mp4  mpg4

A newer standard, devised for conveying both audio and video material, and especially suitable for real-time streaming over the Internet. Such files can be read using QuickTime 6.

  Digital Video  .dv  dvc!

Contains a high-quality movie, as produced by a Digital Video (DV) camera.

  Shockwave Flash  .swf  SWFL

This vector animation format, more accurately known as a Flash media file, was developed by Macromedia for sending real-time images over the Internet. Such documents can be created in applications such as Flash (Macromedia) or LiveMotion (Adobe) and played back in QuickTime.

Flash files are popular on the Web because the files are small, usually containing vector graphics that can be scaled without any loss of quality. However, such documents can be demanding on the computer, even though QuickTime can play multiple media types simultaneously. For this reason, the content of Flash material should be designed to reduce the load on a recipient’s machine. For example, a complex Flash animation should be stopped whenever a video is played.

A total of 16,000 frames are allowed in a movie, which means that a video running at 8 frm/s can last for up to 33 minutes. If you exceed this maximum, Macromedia’s Flash Player comes to a stop at this point. In addition, a movie’s content shouldn’t exceed the 50 MB limit of Flash Player’s memory.

The following data rate combinations are often used to suit various Internet connection speeds:-

ContentConnection (kbit/s)Audio (kbit/s)Video (kbit/s)
Video and audio28.8812
Banner ad video and audio28.8812
Video and audio56832
Banner ad video and audio561624
Video and audio1281694
Video and audio35624218
Video and audio38440324
Video and audio51240452
Audio only14.48 -
Audio only28.816 -
Audio only128112 -
Audio only256224 -

Other formats include:-

  Amiga Animation  .anim/.anm  ANli

As the name indicates, this kind of file is used for animations on an Amiga computer.

  Animated GIF  .gif  GIFf

Although this is the standard format for still images on the Internet, the GIF 89a variation of this kind of file can also accommodate animations and image transparency.

  Atari ST Formats  .ani, .flm, .ic1, .ic2, .ic3  See below

The following animation formats are used on the Atari ST computer:-

FormatExtensionMac OS Type
Neochrome Animation.aniBINA
Animatic Film.flmBINA
Imagic 16-colour.ic1IMAG
Imagic 4-colour.ic2IMAG
Imagic monochrome.ic3IMAG

  Flash Video Format  .flv  ????

A special file format derived from Shockwave Flash and designed for real-time video streaming.

  FLC  .flc/.fli  FLI<space>

Also known as an Autodesk Animator File file, as used for animations in Windows.

  Illustrator Sequence  .ai/.epsf/.eps   PDF<space>/EPSF

A sequence of Adobe Illustrator image files that together form a complete animation.

  Image Sequence  Various

A sequence of standard graphics files that form an animation. QuickTime can create these using BMP, JPEG, MacPaint, Photoshop, PICT, PNG, QuickTime Image, SGI, TGA or TIFF files.

  PICS  .pics/.pcs  PICS

An animation sequence, as used in Director and similar applications.

  RealVideo  .rm  PNRA

A special format devised by RealNetworks for sending movies in real time over the Internet. Related files, known as RealAudio, RealPix and RealText, are used for sound, pictures and text. All of these documents can be viewed using a special application called RealPlayer (RealNetworks).

  Video Object  .vob  ????

This kind of file, produced by cameras that record directly onto DVD, isn’t acceptable to Apple’s iMovie application, although you can use OpenShiva, available from http://openshiva.sourceforge.net, to convert such files into MPEG-4 documents.

  VfW Audio Video Interleave (AVI)  .avi  VfW<space>

AVI movies are used within the Video for Windows (VfW) environment. Although the latter system competes with QuickTime, you can also open these files using QuickTime Player.

  Windows Media, Active Streaming Format  .asf  ASF_

A modern Microsoft format used for streaming movies over the Internet.

References

MacWorld magazine (UK), IDG Communications, 2002-2004

©Ray White 2004.