Successful Webcast Ingredients

Sending raw feeds back is advantageous because it minimizes the amount of computer hardware you need on site. To do so, you must arrange for satellite uplink or fiber connectivity on site. Both of these options have a high degree of reliability, but can be cost-prohibitive. If you’re encoding on site, you’ll need more computer hardware, along with sufficient connectivity to send the streams to the servers reliably, but the cost savings can often justify this approach.

Nowadays it is commonplace to encode across the public Internet. This is not 100% reliable, since you are at the mercy of the local Internet service provider (ISP). A more reliable approach is to secure private, guaranteed, point-to-point connectivity such as ISDN or frame relay. As with most things, however, it comes down to a trade-off between cost and reliability. If there is no room for error, secure private connectivity or use a satellite truck. If your budget doesn’t allow for this, you can probably get by with encoding across the public Internet as long as you keep the bitrate of your streams down.

For the production phase, you’ll need a full complement of audio and video gear to create a broadcast-quality stream. Bring two of everything. It’s crucial to have extra microphones, cameras, mixing decks, and anything else you plan on using to produce your Webcast. If you don’t produce Webcasts very often, it may not make sense to invest in duplicate equipment; using a production partner might be a better approach.

Bring extra encoding hardware for encoding redundancy. At least one backup encoding machine is required—more if you’re encoding multiple bit rates or formats. If you can afford it, you should also invest in redundant connectivity; your broadcast will grind to a halt if your connectivity disappears.

A robust streaming server infrastructure is required to handle the demands of the projected audience. Bandwidth requirements increase dramatically, as does the load on the servers. Depending on the streaming format you’re using, you may have licensing restrictions on the number of streams you’re capable of broadcasting simultaneously.

Make sure you have enough personnel and good lines of communication. Webcasts are far too complex for small crews to pull off. You need individuals responsible for each and every aspect of the event, and they need to be able to communicate with everyone else involved.

Don’t rely exclusively on cell phones—you never know when a cell phone battery will die, or when reception will disappear. It’s best to have access to a land line for external communications, and a headset communications system for the on-site crew. Instant messaging is also a great way to stay in touch with people off site.

Finally, the importance of testing cannot be stressed enough. Test the connectivity on site well before the event. Test the production equipment before the broadcast begins, preferably the day before the broadcast. Test the encoding equipment and load-test the streaming media infrastructure. Test the links on the Web site, and have as many people as possible participate in a dry run of the Webcast. The surest way to minimize the chance of failure is to test as much as possible before the actual event.

Webcasting Production Techniques
You can employ a number of different techniques to make your Webcast production more professional. Most of these are standard broadcast procedures, but a few are specific to Webcasting.

First, make sure your audio and video feeds are noise-free. Connecting two different systems, such as a house PA and an encoding rack, can produce ground hum or video noise. This noise severely impacts the quality of a Webcast and is a quick way to make enemies with the local crew, since the noise is also audible on the PA system.Fortunately, there is a simple fix. Use isolating transformers to connect to other A/V systems. These simple, inexpensive pieces of equipment isolate disparate systems, and virtually eliminate audio and video noise arising from grounding issues. Be sure to carry audio and video isolating transformers in your Webcast kit.

A good audio technique, particularly for entertainment broadcasts, is to use ambient microphones. The ambiance of the location is an integral part of the excitement of any broadcast. Many live events sound dry because the microphones are aimed at the talent, not the audience. Thus, the ambiance is not included in the broadcast. To fix this, simply use a pair of mics aimed at the audience, and mix a bit of that sound into your audio feed.

Use audio compression to protect the equipment and make the broadcast sound more professional. Audio compression protects equipment from sudden increases in level, thereby preventing distortion. In addition, compression makes a broadcast sound more professional by keeping the overall levels more consistent and making the signal sound fuller and "warmer." Remember, viewers have a much lower tolerance for poor audio than they do for poor video. If your sound is sub-par, you’re sunk.

When producing video for Webcasts, bear in mind that streaming video codecs are extremely sensitive to motion, so it’s very important to use a tripod. Ask the camera crew to avoid pans and zooms. Consider framing the subject a little tighter than a traditional broadcast, bearing in mind that most people will be watching on smaller screens, at reduced screen resolution.

There are a number of things to consider when using multiple cameras. As a director, it’s important not to cut from camera to camera too often. While cutting to different camera angles adds interest, it also increases the workload for the encoder, resulting in compromised stream quality. A good rule of thumb is to try to leave ten seconds between cuts.

Be sure you have enough light to produce an acceptable image. If you have ever been in a television studio, the first thing you’ll notice is how bright it is. This is because cameras produce higher-quality images in brightly lit situations. Many inexpensive DV cameras today advertise their ability to film in low-light conditions. What they neglect to say is that the resulting image is extremely noisy. This video noise results in low-quality streaming media files.

A portable lighting kit can suffice for interviews or smaller locations. For larger areas, consider hiring a professional lighting partner. Be sure to tell them that you’re lighting for video. Lighting professionals know that video shoots require more lights, and will plan accordingly.

It’s important to white balance all the cameras, so they render colors accurately. Make sure they’re running at the same shutter speeds and exposure settings. Professional broadcasts employ a shader, whose sole job is to monitor the cameras to make sure they look consistent. If your budget doesn’t stretch to a professional crew and equipment, be sure to at least use consistent settings on all your cameras.

Working outdoors brings with it a whole different set of challenges. You’re at the mercy of the elements, and depending on the location, you may be at the mercy of many other things. Bring windsocks for your microphones and plenty of protective gear for your personnel and equipment. White balance your cameras often as the quality of light changes throughout the day. Double check your power and connectivity the day before the show, and cross your fingers—there are some things you cannot control.

Webcast Encoding
It is very important to consider the audience and how they connect to the Internet when encoding a Webcast. It is crucial to select a bitrate that can be delivered to the audience in real time. Most streaming media viewers are able to receive broadband streams, ranging from 200Kbps (kilobits per second) up to 700Kbps and above. In general, a broadband rate of 200-300Kbps is generally appropriate.

Another bitrate consideration is cost. Most bandwidth providers charge by concurrent Megabits per second, or by total throughput, measured in Gigabytes. Therefore, the total cost for bandwidth usage is directly related to the size of the audience and the bitrate of the live streams. While the quality of a 300Kbps stream will be higher quality than a 200Kbps stream, the cost likely will be 50% greater.

Choose a screen size, or resolution, that is appropriate for the bitrate you’re encoding and the type of content you’re Webcasting. In general, for a 300Kbps stream, you should encode at 320x240. If you’re Webcasting high-action content, such as sports, you may want to reduce the screen size. For dial-up audiences, start with 160x120. If you’re using a modern codec (Windows Media 10, RealVideo 10, Sorenson V3), experiment with larger screen sizes such as 240x180, and reduce if you’re getting unacceptable quality.