Video PrimerVideo Primer

Thank you to the original creators of this presentation:Michael BuchananSenior Forecaster

National Weather ServiceCorpus Christi Texas

Marina Del Rey M.S. & Performing Arts MagnetVideo and film production workshop

Video PrimerVideo Primer

Basic FundamentalsVideo Formats

– Video production– Software– Hardware

The Future of Video

BasicsBasics

What is video?– The famous motto “A picture is worth a thousand words” can be said

of video.– Quite simply, video is nothing more than a series of moving pictures.– The animation of these pictures produces what our eyes see as

flowing motion. No two videos are the same!

– Each video has both universal and unique characteristics that make no video the same from each other.

– This is both the beauty and bane of video. – Many factors determine the ultimate quality of video such as the

equipment used to make the video, the particular chosen video format used, any software involved, etc.

BasicsBasics

Other important factors to consider are some of the following:– Is your video footage digital or analog?– What aspect ratio will your video have?– Is your source video interlaced or progressive?– Is your video NTSC or PAL?– Is your video high definition?

Of course, there are many other topics which we could discuss when talking about video, but let’s focus on the factors above because these will give us a better understanding of how video works.

Video FormatsVideo Formats Video is either analog or digital.

– Analog video signals are in the form of waves.

– Digital video signals are discrete points that can be quantified using 1s or 0s.

Analog sources include VHS. Digital sources include DVD. Analog sources usually have poorer

resolution, poorer quality and shorter lifespan.

– This is one of the main reasons why the world of video is converting to digital.

– Digital video can usually hold onto its quality much longer than analog video.

Analog

Digital

Aspect RatioAspect Ratio 4:3 (Full Screen) or 16:9 (Widescreen) aspect ratios are the two most

common aspect ratios used in video.– The 4:3 aspect ratio means that for every 4 pixels wide that you see, you

will see 3 pixels in the vertical. 4:3 aspect ratio has been around since the beginning of the TV age and is the

most common aspect ratio used in video. A standard definition TV with a 4:3 aspect ratio limits the display of video

content. This overscan area is not displayable in a 4:3 aspect ratio TV but can be viewed on a progressive display such as an LCD computer display (progressive displays will be explained later).

– The widescreen (16:9) aspect ratio continues to gain popularity. The main reason that the 16:9 aspect ratio is favored is because this format

actually displays ALL the video content that the 4:3 aspect ratio cannot. The original intent of the video creator is more adhered to in

widescreen format. Nearly 45% of an original widescreen video is lost when viewed on a 4:3 TV. This will further be explained in subsequent slides.

Hollywood films are normally shot on film in a widescreen format called anamorphic widescreen (2.35:1). This format will produce black letterboxes even on a 16:9 widescreen TV. However, all the original content is able to be seen on a 16:9 TV.

4:3 aspect ratio TV

Interlaced and ProgressiveInterlaced and Progressive

Interlaced vs. Progressive– Interlaced video is composed of two fields (an upper and lower

field). Each field is displayed at roughly 1/60th per second. Taken together, both fields comprise a single frame of video at 1/30th of a second.

– Progressive video is displayed in one full pass at 1/30th of a second. This is the preferred video format due to crisper images and no interlacing artifacts.

Conventional CRT TVs display interlaced video while LCD flat panel computer monitors and many newer TVs such as EDTV and HDTV display in the progressive format.– Progressive displays can also display interlaced content too.

NTSCNTSC

Most video produced in North America conforms to the National Television Systems Committee (NTSC) frame rate of 29.97 pictures per second.– The 60 interlaced fields per second (60 Hz) equals 30 frames of

video per second. Since this standard was developed in the black-and-white TV era, color was not accounted for. So, it was decided to account for color information in the video signal, the frame rate had to be lowered slightly to 29.97 fps.

– There are other frame rates that are allowed in the NTSC standard but 29.97 fps is the most common.

The NTSC standard generally refers to analog video.

NTSC and PALNTSC and PAL

Japan and North America follow the NTSC standard while the rest of the world follow the PAL (Phase Alternating Line) standard of 25 fps.

Hollywood film is usually shot at 24 fps. A typical NTSC TV monitor will have 525 horizontal lines,

of which approximately 480 can be seen on the screen. The actual resolution of a TV signal is typically 300-500

pixels wide by 480 pixels tall with only about 93 percent visible.

– The other 7 percent is hidden and is called the overscan area. This is why the 4:3 aspect ratio is not preferred because video is actually being “hidden” from the audience.

ATSCATSC

ATSC (Advanced Television Systems Committee) was formed in 1982 to develop new standards for digital television and broadband multimedia.

There are now 18 ATSC TV standards. “DTV” or digital TV sets incorporate an ATSC standard. Digital cable and satellite transmissions often employ their

own standards.– The set-top boxes (STB) will convert these different standards into

ATSC standards. Analog transmission is expected to end Feb 17, 2009 and

be replaced by digital transmission.

VHSVHS

Standard VHS tapes have a resolution of only 200-300 x 480 pixels.

S-VHS tapes have slightly better resolution at around 400 x 480 pixels.

Audio quality is usually around 44.1 kHz.– Hissing and other imperfections can show up in VHS

tapes especially with older tapes.– Generally speaking, the poorer and older the source,

the more “noise” will be contained within the video.

DVDDVD

Digital versatile/video disc is one of the best digital video formats available today.

DVD video has a resolution of 720 x 480 pixels.

Audio is sampled at 48 kHz.

DVDDVD

DVD video is encoded in a format called MPEG-2.

Audio can be encoded in Dolby Digital (called AC3), MPEG-2 audio (called MP2) or it can be left uncompressed as a wave file (Pulse Code Modulation).– DTS audio can also be used but is still rare.

DVDDVD

The contents of a DVD video disc (when viewed on a PC) typically have two folders:– VIDEO_TS and AUDIO_TS (Only used for DVD Audio discs).

Within the VIDEO_TS folder, there are 3 kinds of files:– .VOB files contain the actual video, audio, menu and subtitle data.

The VIDEO_TS.VOB is the first play item (This file can be opened to begin the DVD if if does not play automatically).

– .IFO files contain information on chapters, audio tracks and subtitle tracks.

– .BUP files are backup files of the IFO files. Other folders may be present as well and may represent

DVD-ROM data or other unique data.

DVDDVD Hollywood DVDs are often produced on a dual layer disc

known as the DVD-9 standard.– Hollywood DVDs are pressed as opposed to burned. Pressing

DVDs are very expensive but have higher quality than their burned counterparts.

– Recently, there has been an introduction of dual layer or “double layer” discs available to the consumer. These are still very expensive and have not really caught on with the public.

The two most common DVD standards are DVD+R and DVD-R.– Both of these are known as the DVD-5 standard.– Rewritable formats (RW) are also available but are usually less

compatible in DVD players. DVD-RAM is the least compatible standard and is used

mostly with home DVD recorders.

Video CompressionVideo Compression

Why do we need to compress video? Because uncompressed video is very HUGE!

– One second of uncompressed video would require around 30 MB of storage!

Almost all video formats including DVD employ video compression.

The ultimate goal of compression is to offer as much quality as possible while keeping the file size to a minimum.

CodecsCodecs

Codecs are the means by which video is compressed (for delivery purposes) or decompressed (for viewing purposes).

As discussed earlier, DVD uses an MPEG-2 codec.

Some other popular codecs are MPEG-1, RealVideo, Windows Media Video, DV and MPEG-4.

CodecsCodecs

MPEG-1 is probably the most universal codec and is a great delivery codec.– Most PCs have some kind of MPEG-1 codec already installed on their system.

Windows Media Video/Audio is a great codec in terms of quality and compatibility.

– Since most PCs run the Windows OS, this is a safe codec to use for most situations. The RealVideo/Audio codec has a bit less quality than WMV/WMA but it is a

great web video format (i.e., streaming video). DV codec is the codec used in digital video camcorders and analog/digital

converters. MPEG-4 is the codec used in most portable devices such as cell phones, PDAs

and portable media players.– MPEG-4 has a good balance of quality and file size.– DIVX is one of the better known codecs in the MPEG-4 category.

Other video formatsOther video formats

A VCD (Video Compact Disc) is a CD with video and/or audio on it…similar to a DVD but of much less quality.

– The VCD uses a MPEG-1 codec at a resolution of 352 x 240 pixels. A SVCD (Super VCD) is similar to a VCD but it uses an MPEG-2

codec with a resolution of 480 x 480 pixels.– An SVCD is better quality than a VCD but at the expense of limiting

video to less than one hour. The VCD and SVCD can usually be played on a modern computer.

– The VCD and SVCD can be played in home DVD players especially the newer models.

D-VHS tape is a format used to record not only conventional analog data but also record digital data such as high definition video streams.

Video HardwareVideo Hardware

Video quality is contingent to a large part on the actual hardware used in video production.

Video equipment can range from tens of dollars to hundreds of thousand of dollars.

Video hardware that produces good results can be obtained at modest prices.

Dirt cheap hardware will often produce poor or at best only mediocre results.

HardwareHardware

Use an S-VHS or D-VHS player, preferably one with a built-in Time Base Corrector (TBC) and other pre-processing features.– Stick with the higher end JVC models.– JVC invented VHS and Super-VHS technology and are

generally considered the best in the industry, although this is subjective.

Use a stand-alone TBC such as the DataVideo TBC-1000.– A TBC processes each video frame and attempts to remove

any inherent “noise” such as jittery playback often seen on older analog video.

HardwareHardware To capture analog video and convert it into digital

video, you must pass the signal through an Analog-Digital Converter…a camcorder with a digital passthrough capability or a TV capture card attached to your PC.– The Canopus ADVC 100 or 300 series are considered

excellent A/D converters.– Capture cards from Canopus, Matrox, ATI and

Bluefish444 are highly recommended. The result will be the same: a digital video file

residing on the hard disk of your PC.– The digital video file will be encoded with the DV

codec if an A/D converter or camcorder is used.

Computer SpecsComputer Specs

To adequately handle video on a PC, here are some recommendations:– Fast CPU (3 GHz P4 or higher)– Plenty of RAM (At least 1 GB)– Plenty of hard drive space (At least 100 GB)

Several hard drives are actually preferred.

– Firewire port– DVD burner

Other hardwareOther hardware

A broadcast monitor is recommended so that you can view your video on an interlaced monitor.– TV monitors have a much more restrictive range of colors than

computer displays which often can display millions of colors. A DVD printer is recommended so that you can print

directly on printable CDs & DVDs. A home DVD recorder is highly recommended if you are

only interested in straight one-to-one conversion with little to no editing.– Hollywood VHS tapes cannot be copied directly this way due to

macrovision protections found on the actual magnetic tape. A tower DVD duplicator can be a time-saver for DVD

projects that require multiple DVDs.

Video SoftwareVideo Software

You will need some way of manipulating the digital video file that resides on your hard drive.

Non-linear editing software is needed (NLE).

NLE software is the core software you will use to edit digital video.

NLENLE

NLE software can range in price from free to thousands of dollars.

Adobe Premiere Pro, Sony Vegas, Canopus EDIUS and AVID Xpress Pro are some examples of professional NLE programs.

There are many cheaper alternatives that are usually good enough for the average consumer.

Adobe Premiere Elements, Sony Vegas Movie Studio and Canopus Let’s Edit are geared toward consumers.

TranscodingTranscoding

All NLE programs are able to output your final video into a format that your audience can use (i.e., DVD).

The process of transforming video from one format into another is called transcoding.

The most common transcoding that most people will do is to transform captured digital video into a DVD-compliant MPEG-2 format.

Canopus Procoder, Pegasys TMPGEnc and Cinema Craft Encoder are professional transcoders.

DVD AuthoringDVD Authoring

Many NLE programs can output the final project directly to a DVD.

However, if you want to create a more sophisticated DVD with motion menus, multiple audio tracks, subtitles or add DVD-ROM content, then you will need a DVD authoring program.

Adobe Encore, DVD-lab and TMPGEnc DVD Author are some excellent DVD authoring programs.

Many DVD burners come with a basic DVD authoring program such as Sonic MyDVD, Nero or Roxio.

Other softwareOther software

MPEG editing software can be helpful if you still want to edit your finalized DVD-compliant MPEG files.

DVD Player software for your PC such as Cyberlink PowerDVD is recommended.

Adobe Photoshop or other similar graphics program for producing sophisticated menus for your DVD is also recommended.

An audio restoration program such as Adobe Audition, Sound Forge, Goldwave or MAGIX Audio Cleaning Lab is recommended.

The future of videoThe future of video Standard definition (SD) video is referred to video produced at

resolutions of 720 x 480 pixels or less. This resolution is many times referred to as 480i (interlaced) or 480p (progressive). The majority of video seen by people today is in a SD format.

However, high definition video (HD) is beginning to gain popularity. HD video comprises 3 different formats under the ATSC standard.

– 720p (1280 x 720 pixels)– 1080i (1920 x 1080 pixels)– 1080p (1920 x 1080 pixels)

These 3 formats represent the highest resolution possible under the ATSC standard. 1080p is the absolute highest resolution but very few display devices are capable of displaying 1080p source video.

Most HD terrestrial or satellite broadcasts are transmitted in 1080i format.

HD VideoHD Video

HD video is in a widescreen format.The audio portion of HD video can support

multi-channel sound (surround sound).– Multi-channel Dolby Digital, DTS and

uncompressed audio (LPCM) are supported.

Full resolution HD video has more than 6 times the number of pixels as SD video.

HD DVD vs. Blu-rayHD DVD vs. Blu-ray

The final piece of the transition to HD video has been the end product.

HD DVD and Blu-ray are two competing optical disc formats that will be launching in 2006.

Each optical disc will be able to play HD video along with HD audio formats.– MPEG-2, MPEG-4, WMV 9 video codecs

Both new formats require a new reader and writer due to the smaller blue laser wavelength that is used.

Blu-rayBlu-ray

Single layer Blu-ray discs will hold 25 GB while dual layer discs will hold 50 GB of storage.

Over 2 hours of HD video can be stored on a single layer disc. BD-ROM is a read-only format, BD-R is the recordable format and BD-RE is

the rewritable format. The official launch of Blu-ray technology will occur in late spring of 2006. Playstation 3 will have Blu-ray technology built into it.

HD DVDHD DVD

Single layer HD DVD discs will hold 15 GB while dual layer discs will hold 30 GB of storage.

HD DVD-ROM is the read-only format, HD DVD-R is the recordable format and HD DVD-RW is the rewritable format.

HD DVD will launch in early spring of 2006.

Format warFormat war

It is too early to say which optical disc format will win.

The prevailing opinion is that Blu-ray has an edge due to its wider Hollywood support and higher storage capabilities.

This format war is very similar to the VHS and Betamax format war 20 years ago.

ConclusionConclusion

Video comes in many formats, resolutions and is produced in a multitude of ways.

The goal of this presentation was to hopefully provide enough relevant information for a novice or beginner to make informed decisions when trying to incorporate video content into his or her profession.