Television Production Handbook 
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1980-2009 Roger Inman & Greg Smith. All rights reserved.

Getting the Word Out

Videotape
VHS videotape is still a viable distribution option preferred for audiences that are resistant to change.

CD
There are several ways to distribute video on CD’s.  They have been especially popular as a medium for motion pictures using the MPEG 1 standard.  The quality of these “video CD’s” is about the same as VHS.  
Some DVD authoring software can be used to make CD’s that behave like DVD’s.  The total run time for these disks is about fifteen minutes. The special software needed to play back the CD content is included on the disk.  These CD’s are for computer CD/DVD drives only and are generally programmed to run the software automatically when the disk is inserted.  While this is a viable way of distributing DVD-quality video to computer users, its usefulness diminishes as new computers are delivered with DVD drives as standard equipment.  

It is also possible to make CD data disks that contain MPEG 2 or Windows Media Format files.  Most computers now have the codecs needed to play MPEG 2 or WMF files.  Again, at about four Mb/Sec a CD can hold about fifteen minutes of video.  The increased compression of the WMF format allows more than sixty minutes on one CD.  The WMF format fits the specifications for MPEG 4, the compression regimen designed to accommodate high definition television.  Both Quicktime and Real Player also offer compressed video formats that can be included on data CD’s.  The appropriate players will have to be downloaded by your viewers.

Finally, there is software available for authoring data CD’s, or CD-ROM’s.  These software packages allow the integration of files on the disk with files on the internet in addition to many of the navigation features common to DVD’s.
 

DVD
One popular way to distribute video is the DVD. A DVD is an optical disk, actually a reflective film sandwiched between two protective acrylic layers, like a CD, but with some differences. The most important difference is that a typical DVD can hold up to 4.7 GB of data, including formatting information on a single layer disk and twice that on a dual layer disk.  You have roughly four gigabytes of space available for project on a single layer disk.

There are two ways of using DVD technology to distribute video.  The traditional method is to use DVD authoring software to create a DVD that can be played on a stand-alone DVD player, typically called a “set top” player.  Set top players require a specific  MPEG 2 format which makes it nearly impossible to reverse-engineer the video for editing.  This DVD format is ideal for distribution.  In small quantities you can make your own DVD’s with relatively inexpensive software and hardware.  Color printers capable of printing directly on the DVD face are very affordable as well.  It should be noted that from the beginning there have been problems with compatibility between DVD-R and DVD+R disks and some set top DVD players, especially models made before 2001.

For large quantities you’ll want to use a commercial disk replicator.  Replication is a two step process.  First a glass master disk is made. Then the master disk is used to press or stamp a reflective disk, which is then sandwiched between two acrylic layers for protection.  The minimum cost for replication is usually the same as the cost of making 800 to 1000 copies.  In other words, whether you ask for one hundred, two hundred, or a thousand copies of your masterpiece, the total cost of replication (not including album cases or other packaging) will be about the same.

Most commercial disk replicators will now accept a DVD-R as a master, although the preferred medium for mastering DVD’s is DLT, or digital linear tape.  DLT was developed to backup or archive computer networks and servers.  If  you want digital copy protection for your DVD’s you will have to submit your masters on DLT.

 When dealing with a commercial replicator, be prepared to be able to prove you have the right to use all of the audio and video on your disk.  Replicators do not like to be sued.
 

Making a DVD

A DVD can be as straightforward as a videotape.  Pop it in the player and the program runs from start to finish with no embellishments.  Or it can have a complex system of menus allowing the viewer to select various programs or go to specific points within programs.  Menus can allow viewers to select different audio channels or call up subtitles.

The first step in making a DVD is to assemble all of your finished media as digital files.  There are only limited opportunities to edit materials in DVD authoring software.  It is best if all of your materials are in final form before you go any further.  Audio files should be in the .wav format.  Your video files are probably either Quicktime or .avi files.  They must be converted to MPEG 2.  This option should be available in your video editing software.  If you have optional audio tracks you can convert your video using your primary mix of audio tracks, then save your secondary mix of audio tracks separately as a .wav file.  You can do this by turning the appropriate tracks on or off before exporting the file.  In addition, you may have still images you want to use in your DVD, perhaps as menu backgrounds or buttons.  Full frame stills should be 640x480 pixels for NTSC or 640x576 for PAL.  Your DVD authoring program will change these stills, which have square pixels, to 720x480 or 720x576 pixels where the width of each pixel is nine tenths of the height.  The difference is pixel aspect between digital stills and digital video affects all of your still images, whether full frame or smaller.

Your authoring software will allow you to import video, audio, and still image files.  The categories may be straightforward or have more imaginative names, such as “Media,” “Backgrounds,” and “Buttons.”  

At this point it may or may not tell you if your project will fit on a DVD.  You have about four gigabytes available.  If your project is too large you can go back to your video editing software and change the MPEG 2 conversion settings to increase the compression and decrease the file size of each MPEG 2 file.  While the DV files you generally work with in your editing software are compressed to about four Megabytes per second, MPEG 2 files are generally compressed to from 3.5 to 8 Megabits per second.  At the lowest compression you have a little over an hour of video on a DVD.  At the highest compression you can get about two hours on a disk.  As you increase the compression of your video files you also increase the chance that you will lose detail in your video during quick movements.  The loss of detail will take the form of pixilation.  Your video will be reduced to a jumble of blocks until the rate of video change returns to a more normal rate.  You should probably keep your data rate at four megabits per second or higher.

There is actually more to the MPEG 2 format than the data rate.  While in the DV format compression is achieved frame by frame, MPEG 2 is divided into groups of pictures (GOP’s) usually twelve to fifteen frames long.  The first frame (I) of each GOP has all of the information necessary to reconstruct the frame. The remaining eleven to fourteen frames (P and B frames) contain only enough information to reconstruct the video by combining information from previous frames (P frames) or by combining information from both previous and following frames (B frames).

The best consumer authoring programs will allow you to import your video and use it to create all of your menus and buttons in a very straightforward and intuitive way.  Typically, once you’ve imported your video clips you can select one of several menu styles.  If you have more than one video clip, you can assign each clip to a button on the menu.  You may even be able to create intermediate menus and use the time line of your video you can select chapter points and drag those points to menu buttons.  In some cases the video from the clip will form a still image in the button automatically.  When you’re done you usually have at least two options: burn one or more DVD’s using the current project settings, or create a file that is an exact image of the contents of the DVD.  When you burn your DVD’s from the current project your program will create a temporary file on your hard drive in which all of your materials are converted into the required DVD format.  Your disks are burned from the temporary file, which is deleted as soon as the disks are done.  When you elect to create an image file, the file is created on your hard drive but no disks are burned.  You can use the image file to burn your disks later as you need them.

Professional software will allow you to do anything you’ll see on a commercial DVD.  Professional software is not, as a rule, either user-friendly or intuitive.  It is more powerful and flexible.

The Internet
Using video on the internet creates a set of considerations and problems that should be part of the video planning process before any video is shot.  The basic fact about the internet is that it was never designed to transmit video and audio at four megabytes per second or even four megabits per second.  To send video over the internet more compression is necessary.

There are several compression schemes for internet video that rely on four ways of reducing picture information.
1. They generally reduce the frame size.
2. They reduce the frame rate.
3. They reduce the amount of information in each frame beyond the compression available in MPEG 2 by sacrificing picture quality when content in moving and maintaining higher resolution when images are relatively still.
4. They “buffer” the bit stream.

Reducing the frame size reduces the amount of picture detail available and should be an important consideration in shooting for the internet.

         
         Sidewalk at 640x480
        
640x480 pixels    

Sidewalk at 320x240
320x240 pixels  

Sidewalk at 160x120
 160x120 pixels

Loss of detail can turn excellent images into mud.  Just as commercial motion pictures are often shot not for the resolution available with 35mm film, but with the more limited resolution of NTSC video in mind, you should shoot for resolutions much lower than standard video.

After decades of experimentation the film industry settled on a few frame rates.  For silent consumer film either sixteen or eighteen frames per second was used.  There was a noticeable flicker when films were projected at these rates.  Commercial sound motion pictures are projected at twenty-four frames per second.  The frame rate for NTSC television is thirty frames per second.  Frame rates for streaming video are often below fifteen frames per second.  The impact on motion is obvious.  At fifteen frames per second, how many frames does it take to swing a baseball bat?

The third method of reducing the data rate, sacrificing detail during motion sequences, further “muddies” the picture.  Motion and fine detail are mutually exclusive in the world of streaming video.

Buffering can be as simple as actually downloading the entire video at one rate in order to play it back on a computer at the designed normal rate.  More commonly, playback is delayed until enough data has been downloaded to allow playback of a significant part of the video.  When the playback catches up with the download (and runs out of data to play) the playback is paused until more data is downloaded.  This process often causes awkward pauses during playback, but that’s progress.

Streaming video should accommodate a range of users, from those with 56 Kbps dial-up modems to those with DSL and cable modems receiving in excess of one gigabit per second at the modem (but less than 54 Mbps over their wireless network).  When you export video from your editing software you will have the option of two or three streaming formats.  Pick the one you believe will offer your viewer the best picture quality, given the content of your video) with the least inconvenience and delay.  Each of these will in turn allow you to choose either a single streaming rate or multiple rates dependent on the viewer’s reception rate.  

All that’s left to be done is to move the finished streaming video file onto a web site for downloading.


Archiving your work
Most of the time most artists want their work to last at least as long as they live.  Throughout recorded history we have been able to save some pieces of art or literature on  cloth, paper, stone,  or metal.  Each of these has properties that cause the information to degrade, but all have one thing in common:  It does not take any equipment beyond the human eye to recognize and read the information, although the eye may need a brain behind it trained in hieroglyphics or  ancient Greek.

Times have changed.  Your hardware may become obsolete or even incompatible with newer operating systems.  Changes in the computer world have given an entirely new meaning to the word “legacy.”  Until recently the word referred to property inherited or traditions passed down from one generation to the next.  In the computer world “legacy” has become an adjective referring to the data in any application that can no longer be used by readily available software or hardware.  The 5 inch floppy disk is a legacy system in that no computers sold today can read those disks.  The 3 inch floppy disk is pretty close to legacy status itself.  As you move from one operating system to the next or from one capture card to a different brand you risk rendering all of your .avi files unreadable.  Keep the tape.  And while you are at it, take very good care of your playback equipment, too.

So far we’ve gone through the following videotape formats:  Two-inch quad, one inch helical of various formats up through type C, half- inch EIAJ reel to reel, U-Matic and U-Matic SP, Betamax, VHS, Betacam and Betacam SP, M2, S-VHS, 8 Millimeter, and Hi-8 analog formats; DV, Digital 8, DV Cam, DV Pro, Digital Betacam, a more.  If your tape is stored properly at moderate temperature and humidity you are more likely to have trouble finding playback equipment than you are to have trouble with the videotape itself.

The best you can do is to make copies of your work in the highest quality digital format you believe has a user base large enough to keep it in use for a long period of time and that you can afford.  While many are choosing to “archive” their work on DVD in MPEG 2, that medium is much more highly compressed than the DV format, which is in general use and slowing replacing both VHS and 8mm as the recording format of choice, both by amateurs and many professionals.  For works under fifteen minutes DV files can be stored as .avi or .mov files on DVD-R disks without further compression.  A dual layer writable disk could hold up to thirty minutes. With the advent of high definition video there is no way to know how long the equipment to play back standard definition tapes will be generally available, while current DVD drives and both blue laser disk formats can play material on existing DVD-R disks.  Properly stored DVD-R disks should last at least one hundred years, while rewritable disks can be expected to last at least twenty-five years.  Considering the formats and equipment in common use twenty-five years ago, you should be prepared to re-record your work to new formats as it becomes advisable or necessary.

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