- Quality Does Matter
- Choosing a Capture Card
- Encoding Software: the Key Ingredient
- Need for Bandwidth
Encoding Software: the Key Ingredient
The next step is a big one. As your camera (or source footage) is being sent to your computer, the capture card and capture software play an extremely critical role in the quality aspect of your finished video files. Here is where your video files are being compressed. The nature of uncompressed video files, compared to audio files, is incredible. Although a few minutes of audio may take up only a megabyte or two, video files can reach into gigabytes in terms of file size. Most computers are not capable of playing or transferring full-sized, uncompressed video files. The computer's internal components cannot handle a data rate fast enough to reproduce the image, frame after frame, second after second. This is what causes the signal to get bottlenecked and results in either very jumpy and jerky motion video or freezes up the whole computer entirely.
What's more important, if you have to then send this signal over the Internet (which has much less transfer speed and bandwidth than the internal speeds of your computer), no one would ever be able to transmit or receive files that large. Therefore, you must compress the video signal. Whether you are webcasting the event live, which means basically capturing and encoding the video source into a Web-friendly format at once, or whether you can record the video signal to your hard drive first and process it for the Web at another time determines which type of encoding software you use.
Once again, there are many developers out there with their own versions. You need to pick one based on cost, ease of use, and final format. If you are going for a live webcast, you may want to check out software packages such as CU-SeeMe, Microsoft NetMeeting, or WebCam32just to name a few. Many of these applications offer free trial versions. I recommend downloading a number of different ones and trying them out until you find the one that offers you the best features for the type of webcast you are trying to complete with the highest-quality imagery. Remember, your computer is trying to run software while capturing a video sign and compressing it into a Web format, all at the same time. Unless you are running some supercomputer, don't expect miracles. Be realistic about what you can expect the quality to look like and still perform flawlessly.
If you are capturing your footage to your hard drive first before your encode the material for the Web, you still need to consider what type of initial compression to use on your source footage. This is where you work with a native compression format or codec (which stands for Compressor/Decompressor) of your capture card, which enables your computer to reproduce the video files without any problems after they are stored on your hard drive. Many cards offer multiple codec formats (for example, .AVI, QuickTime, DV, Sorenson, Motion JPEG, MPEG, Indeo, and Cinepak). Each one has its own unique characteristics and quality. Some may require additional video drivers in order to play the digital files on another system. You'll have to experiment to find which formats offer you the best results.
After the files are saved on your hard drive, you have to convert them to a Web-friendly formatone that is specially designed and supercompressed for streaming over the Internet. The two key players in this field are Real Media and Windows Media Formats. Here again, there are numerous software-conversion packages available on the market. One of the best is Discreet's Cleaner 5. It has become the industry standard for converting files from just about any format to just about any format known to man, but it does come with a price tag.