Digital Video, a crash course Part 2 – Choosing a Format


Casio Exilim EX-V8
It’s not a videocamera but makes a good stand-in!

In a previous post, I mentioned that until recently, I had not really bothered much with video. So you can imagine my surprise when Adobe Premiere Elements informed me today that I have almost 400 video clips taken since 2005, sitting on my hard drive! I have never really done anything much with them because I lacked the tools and the knowledge to do so.
Then last year when my daughter, Christa was planning to get married, I wanted to put together a photo-montage. I happened to have a FREE version of PowerDirector 6 sitting on my system and tried it out along with various other programmes. To make a much longer story short, I became hooked on PowerDirector and bought the Full Version and discovered that it gave me the capability of doing some pretty amazing things with video as a bonus. Since that time, I have purchased the upgrade to version 8 which adds even more capability.
However, I am getting a little ahead of myself here. Unless you are using your cellphone to shoot video, chances are that your video capture device has some options that you can (and probably should) set. Before you start actually shooting, you need to think about what is the end purpose of your production. There are sometimes as many as 6 different aspects of the finished clip that you can affect with your settings:

1. Aspect – Generally, your choice is between 4:3 standard TV or Monitor or 16:9 which is widescreen. The choice is not as straightforward as you might think. The choice mostly depends on where your video will most often be displayed, but also whether it will be stand-alone or combined with pictures or other videos. In this case, you need to shoot in the aspect that will be MOST compatible with the other media.

2. Frames per second – The video that appeared in our previous post was shot at 10 fps and it shows! 30 fps is broadcast quality. Anything less than 15 fps is of really poor quality. Actually, for some perverse reason, the real industry standard is 29.7 fps. If you find your audio often getting out of sync with your video, it is most likely due to your software not accurately timing it to 29.7 vs. 30 fps.

3. Compression Quality – To some degree, this is tied in with Video Codec (below). Just as jpeg and gif formats in graphics cause differing levels of loss of quality according to the amount of compression applied, so the same holds for differing video codecs. And often, within each codec, there is an ability to alter the amount of compression. Of course, there is always a trade-off between file size and picture quality. Again, you should think of your perceived end use. There is little point in using wide-screen, high-definition, minimum compression recording just to play it back on your cellphone!

4. Audio Quality – On the older digital cameras, you often had to make a choice between higher frame rate and no sound and lower frame rate with sound. Neither was really acceptable. The fact was that these devices did not have enough processing power to effectively handle video. Now, many digital cameras even have the ability to record stereo sound. My Casio exilim V8 is one such and its quality is very good. Unfortunately, although it can record UHQ video, it cannot reach the hi-def quality of my Canon T1i which only records monaural sound ;-( Such are the trade-offs to be considered.

5. Video Codec – Usually, you will not have much choice in the encoding format used by your camera. For some reason, the majority seem to have opted for Apple’s quicktime (.mov). However, there is a giddying array of video file extensions and you should be aware that behind each extension is a wide variety of encoding-decoding schemes, such that you cannot assume that because a file has a particular extension that it will necessarily be compatible with your playback device.

6. TV playback format – Finally, if your finished product is destined for DVD or TV playback, you have to contend with NTSC, PAL and SECAM. Different countries use different TV display systems. North America is almost universally adheres to the NTSC standard, while much of the rest of the world uses either PAL or SECAM. The principle difference lies in the lines of resolution (525 NTSC, 625 PAL).

To give you something to compare with last week’s somewhat dismal offering with low resolution, no sound and slow frame rate, this week we offer UHQ, 848×480 30fps and stereo sound. You are viewing the raw file exactly as it was downloaded from the camera. Because the file is encoded in the Quicktime format, your browser may need to download Apple’s Quicktime plug-in in order for you to view it (double-click to start playback).