12 January 2009
This article is the sixth in a loose series of beginner's tutorials. This particular tutorial shows you how Adobe Flash CS4 Professional, Adobe Flash Media Live Encoder 3, and Adobe Flash Media Server 3.5 team up so you can create live video streams from your own webcam or other sources.
Here are all the articles in the series:
As a Flash teacher and lecturer who tends to spend an inordinate amount of time in the Flash space, I love to show my students how to use a webcam with Flash. It is one of the easiest things to learn and it has immediate rewards. Inevitably, though, the question is asked: Can I stream this live?
Depending on the audience, this is a rather awkward question to answer. If I am dealing with an advanced group that has a deep understanding of ActionScript, the answer is, "It's a little tricky but not terribly difficult to accomplish." For everyone else, the answer is, "You really don't want to go there."
Until the release of Flash Media Server 3.5, there was also a bit of a gray area: Flash shipped with a set of communication components that could be wired together to create a live streaming video application. These components disappeared with the release of Flash CS4 and Flash Media Server 3.5. You would think I would be a bit bummed that my gray area was pulled out from under me. Not even close. Now when I'm asked about streaming live video, my response is, "Can you click a mouse and type one line of code?"
In this exercise we are going to do the following:
Every now and then an amazing piece of software hits the street. Inevitably, the company puts it out in public beta and you can't help but think, at some point in the process, "Dang, this is sweet. I sure hope I can afford it." I had that reaction when I first tried out Flash Media Live Encoder (FME). If the truth be known, I still have a hard time grasping the fact that this powerful piece of software is a freebie.
Its purpose is quite focused: to grab a video or audio feed, on the fly, and either encode it or stream it out—live. In this part of the exercise, I'll take you through the FME interface and use it to create an FLV. Keep in mind this will be a "drive-by" exercise; I won't get into the nuts and bolts of using FME. My colleague, Greg Hamer, has already done a really good overview of this process in his article, Webcasting live video with Flash Media Live Encoder.
Follow these steps to make the initial configuration in Flash Media Live Encoder:
Figure 1. Flash Media Live Encoder interface (click to enlarge)
The input area is further subdivided into separate Video and Audio areas where you can tweak the settings prior to capture or broadcast. If you are unsure of the settings to use, select one of the three presets in the Preset pop-up menu. Still, it doesn't hurt to try this application out, so let's create a simple capture.
Note: You can use a variety of webcams and even digital video recorders to capture the video. As it says in the FME support documents: Flash Media Live Encoder is designed to work with any Microsoft DirectShow–compliant device or driver. For a list of devices that Adobe has specifically tested, visit the Flash Media Live Encoder Device Compatibility Matrix (PDF, 13K). This list is in no way definitive; it simply lists devices tested by Adobe so far. Your first clue as to its (in)completeness should be the missing iSight camera.
At the bottom of the window, you will see the total bit rate, which is the sum of the audio and video bit rates. This is an important number because it has a direct effect on user experience. If you are unsure as to what numbers to use, head over to Robert Reinhardt's Flash Video Bitrate Calculator.
Having dealt with FLV settings, you can turn your attention to actually creating the FLV file:
Now that you have created an FLV file, it's time to play it:
Now that you know how to create an FLV file using Flash Media Live Encoder, it's time to put that knowledge to work and create a live broadcast. Here's the interesting thing: the workflow is essentially the same as in the previous exercise. The difference is that, instead of creating a file, you broadcast your stream through Flash Media Live Encoder directly into a web page. Here's how:
In the previous step I used the word "almost" deliberately. You will need to create the Flash file that receives the feed from the live folder of your Flash Media Server:
myVideo.isLive = true;
isLive property of the FLVPlayback component can have only two values:
false. This property works only if the feed is streaming from Flash Media Server. If you were not using Flash Media Server—that is, progressively downloading the video from an HTTP address—and you set
true, then Flash would simply ignore the ActionScript and nothing would happen.
Having created the "feed" using Flash Media Live Encoder and created the SWF file that receive that feed in Flash CS4, you can put your webcam to work and create a broadcast:
This tutorial showed you how Flash Media Server 3.5 and Flash Media Live Encoder combine to give you a simple-to-master live video and audio streaming capability. If this subject has caught your attention, here are a couple of other articles that will get you going:
Tutorials & Samples
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