Now broadband is getting more and more widespread, the future of the internet is firmly on moving pictures. This opens up many possibilities for astute webmasters to steal a march on their competitors, by using video of themselves to develop a closer realtionship with both prospects and customers.
The advent of streaming video is particularly good news for all information publishers, because the old adage about a picture being worth a thousand words is even more valid when the pictures move!
This opens up tremendous possibilities for websites related to sports, martial arts, self defense or indeed where, in order to demonstrate "how to do it", you need to show the actions. In fact, master streaming video and your website becomes your very own TV station!
Authoring: This is an optional part of the process of making a video. Once the material has been rendered, into the appropriate format, it can either be uploaded to the server (if streaming video) or it can be burnt onto a DVD for replay in a DVD player.
If other features, such as chapter breaks or special effects, are required, these are added at the authoring stage which can be carried out in between rendering and uploading to the server or burning onto a DVD.
Burning: This is the process of putting the rendered and authored video onto a DVD, which can be played back on a DVD player.
The process uses a minute laser beam to vaporize the coating on the disc, which then exposes the silver coating underneath. This results in a stream of minute silver dots, which can be read by the laser on playback and translated into a digital signal.
3CCD chip: This is a multiple unit with each of the three primary colors having their own chip. This gives superior results, compared with the single chip in most home video cameras. These chips normally only feature in professional quality cameras, although Panasonic are introducing them into their home digital cameras.
DV tape: This is a tiny video tape – like a miniature VHS video tape. However, unlike an analogue VHS tape, these tapes record a digital signal, which means no loss of quality. These are used in both home and professional digital cameras and are (at the time of writing) just about the best system.
The tapes run for 60 minutes on standard play or 90 minutes on long play. If you are recording a long production, having the download tapes hour long tapes (downloading in real time) into your computer, before you can start editing the movie, is nether efficient nor fun!
Professional cameras and some home ones (such as Panasonic) allow direct streaming of the digital signal straight into a special portable hard disc, as you record the event. This allows immediate editing without the need to spend hours waiting for DV tapes to download.
DVD: Stands for Digital Versatile Disc. As the name implies, the discs are very versatile with powerful variable bit-rate MPEG-2 video compression, multiple audio format support allow it to be used for far more that the obvious video storage.
The disc can hold either a single layer of information or be dual layer. Dual layer DVDs work by having two separate layers of information, which are read one after the other by a change in the focal length of the laser.
The fact that these discs can hold a single or double layer of information and a dual layer disc can accommodate a full length movie, ensured it was quickly accepted by all consumer electronics manufacturers and all the
Most movies are on dual layer discs, although for information publishing single layer discs, storing a maximum of about 4.7 Gigabites are more manageable and popular.
With the advent of Blu Wave and other technologies, storing even greater amounts of information is now possible.
DVD formats: These come in a bewildering range of formats, but - in essence - there are three classes.
DVD RAM: This is the most specialist format. RAM stands for Random Acess Memory and these are not generally used for writing video to be played on home DVD players, as they are incompatible with most DVD drives or players. They tend to be used for optical storage of vast amounts of computer data – with a capacity far in excess of a CD Rom.
DVD RW: This stands for DVD ReWritable and these discs can be reused again and again, rather like the old floppy discs. These are ideal for time slip recordings, where you want to record a TV program to watch at a different time to when it was transmitted. Having seen the program you are likely to reuse the same disc for a similar purpose. There is a choice of DVD+RW and DVD-RW, which will depend on your particular recorder.
DVD R: This is the more familiar recordable once DVD you are likely to use if you make DVDs from your videos. This group also has DVD+R and DVD-R discs. You should check with your local supplier, but generally speaking I have always used DVD-R discs, without problem.
Firewire: Also known as an IEEE 1394 cable or – if you are using a Sony camera – "i-Link".
This is a special high speed cable used to download the digital signal recorded on the DV tape in the camera into the computer for editing.
Frames: The idea behind the ability of MPEG systems to fit vast amounts of digital information onto a small disc, owes much to the hand drawn cartoons of Walt Disney.
Digital works in the same way as movies used to photographed – a series of frames (around 30 per second). However, there is generally very little change between successive frames. This is just like the hand drawn carton of yesteryear, where they saved hours of work by using a separate and unchanging background and merely redrew the moving parts of the action on different sheets of transparent acetate,
The MPEG uses the same technique, but in an electronic fashion, using a series of frames. First all the details are captured on a reference frame, called an Intra Frame or I-Frame.
Next, by analysing how the makeup of that frame changes over time, the MPEG predicts what changes will occur between the frames and produces a Predicted Frame or P-Frame. This means it only needs to encode the difference between the two frames, rather than produce two entire sets of information – resulting in a great saving of the amount of information needed to be recorded.
To further compress the information into a smaller space a Bi-Directional or B-Frame is created. This B-Frame looks at both the I and P Frames to calculate the least number of bits needed to encode these frames.
IEEE1394: Also known as a "Firewire" or – if you are using a Sony camera – "i-Link".
This is a cable that downloads the digital signal recorded on the DV tape at 400 mega bites per second to the computer from the camera, prior to editing.
i-Link: This is Sony's own term for the more commonly known "Firewire" or EEE 1394 cable. This is a high capacity cable allowing fast downloading of the digital signal on the camera's DV tape into the editing software in the computer.
MPEG: Pronounced "em peg", stands for Motion Pictures Experts Group and is the standard for compressing all that mass of digital information and fitting it onto a relatively tiny DVD.
The basic principle is to slim down the information needed to reproduce the creator's original intention by predicting how much or how little the video image will change from one frame to the next, by using a form of digital shorthand. This results in the need for far less information to be stored and thus making a DVD capable of storing a full length movie.
MPEG1: This was the original, and most basic of the standards. It generally produces a resolution of 352X240 pixels at 30 frames per second (NTSC) and is the method used to provide digital video files on CD ROMS and VCDs. The picture quality is roughly equal to VHS tape.
The MP3 format is part of MPEG1, being defined as Layer Three in the MPEG1 Specification. Hence the corruption to MP3.
MPEG2: This is a more advanced standard and is currently used for DVDs, digital cable transmission and digital television broadcasting. This system allows for higher compression and better quality than MPEG1. It is most commonly used as 720 X 480 pixels at 30 frames per second (NTSC) for both DVD and Digital TV broadcasts.
The audio compression system used for MPEG2 is Advanced Audio Coding (AAC). This features more advanced compression, whilst producing better audio quality than MP3.
MPEG4: This is the latest of the MPEG formats - and the most advanced. Not only is the compression improved over MPEG2, it also has the ability to describe different areas of the video image as separate objects. This allows interactivity with parts of the video.
MPEG4 can also customize the audio and picture quality to the particular device being used. For this reason it is the system used in cell phones and streaming media, animated graphics and interactive television.
Rendering: When a video is created it consists of many separate elements: the video and sound track, still shots, sound effects, background music and special effects, such as a green screen.
Rendering means reducing all this information down to a single stream of code that can be burnt onto a DVD or put on a internet server and streamed to visitor's computers on demand.
The striking aspect of rendering is the sheer amount of time it takes! As a round guide – depending on the amount of additional material involved – rendering takes three times as long as the actual playing time. So a twenty minute video will take about an hour to render.
So always schedule rendering when you plan to do something else away from your computer for quite a while.
Streaming Media: This is audio and video content from a website that can be played in real time on a computer, without having to download the (very large) file that would take a great deal of time to actually download.
If the user has broadband the video starts almost immediately. With dial up there is still a short download time. Streaming media files are not stored permanently on the computer hard disc, but use the computer's working memory as a buffer to hold a part of the video in reserve whilst it plays. This allows the media to play smoothly even if the download rate varies.
Streaming Media Formats:
RealNetworks - RealAudio and Real Video: Both these formats work on Windows PC and Mac operating systems, making them widely used. Both formats use the RealOne™ Player. The file tag is .rm.
Apple Quick Time: Despite being from Apple, this system works both on Macs and Windows PC operating systems. Quick Time is more than just another format, as it has excellent compression and allows for quite complex media authoring. The file tag is .mov.
Windows Media: This is Microsoft's media player, which features AAC (advanced audio coding) and many other powerful features. It is widely used as it comes ready loaded to most Windows operated PC computers. The file tag is .wmv.
Flash: Flash is used increasingly on the internet, because it can integrate many different types of media, including video, audio, graphics and text, as well as allow a high degree of interactivity. The file tag is .swf.
VCD: This is half way between an ordinary CD and a full blooded DVD. It is essentially a compact disc that holds a limited amount of moving pictures, still pictures and sound.
It uses the less advanced MPEG-1 video compression and the picture quality is about that of the old VHS cassette tapes. It comes in two capacities: 650 megabites, giving 74 minutes of full motion video and sound and 700 megabites, giving 80 minutes of full motion video and sound.