Testing a movie > Testing movie download performance |  |

Testing movie download performance

The Flash Player attempts to meet the frame rate you set; the actual frame rate during playback can vary on different computers. If a movie that is downloading reaches a particular frame before the frame's required data has downloaded, the movie pauses until the data arrives.

To view downloading performance graphically, you can use the Bandwidth Profiler, which shows how much data is sent for each frame according to the modem speed you specify. In simulating the downloading speed, Flash uses estimates of typical Internet performance, not the exact modem speed. For example, if you choose to simulate a modem speed of 28.8 Kbps, Flash sets the actual rate to 2.3 Kbps to reflect typical Internet performance. It's helpful to test your movie at each speed you intend to support, and on each computer you intend to support. This allows you to make sure the movie doesn't overburden the slowest connection and computer it is designed for.

You can also generate a report of frames that are slowing playback, and then optimize or eliminate some of the content in those frames. See Optimizing movies.

To change the settings for the SWF file created by Test Movie and Test Scene, use File > Publish Settings. See Previewing and testing movies.

To test downloading performance:

1 | Do one of the following:
| Choose Control > Test Scene or Control > Test Movie.
| If you test a scene or movie, Flash publishes the current selection as a SWF file using the settings in the Publish Settings dialog box. (See Publishing Flash documents.) The SWF file opens in a new window and begins playing immediately.
| Choose File > Open, and select a SWF file.
2 | Choose Debug and select a downloading speed to determine the streaming rate that Flash simulates: 14.4 Kbps, 28.8 Kbps, or 56 Kbps. To enter your own settings, choose Customize.
3 | When viewing the SWF file, choose View > Bandwidth Profiler to display a graph of the downloading performance:
| The left side of the profiler displays information on the movie, its settings, and its state.
| The right section of the profiler shows the Timeline header and graph. In the graph, each bar represents an individual frame of the movie. The size of the bar corresponds to that frame's size in bytes. The red line beneath the Timeline header indicates whether a given frame streams in real time with the current modem speed set in the Control menu. If a bar extends above the red line, the movie must wait for that frame to load.
4 | Choose View > Show Streaming to turn streaming off or on.
| If you turn streaming off, the movie starts over without simulating a Web connection.
5 | Click a bar on the graph to display settings for the corresponding frame in the left window and stop the movie.
6 | If you want, adjust the view of the graph:
| Choose View > Streaming Graph to show which frames will cause pauses.
| This default view displays alternating light and dark gray blocks representing each frame. The side of each block indicates its relative byte size. The first frame stores a symbol's contents, so is often larger than other frames.
| Choose View > Frame by Frame Graph to display the size of each frame.
| This view helps you see which frames contribute to streaming delays. If any frame block extends above the red line in the graph, the Flash Player halts playback until the entire frame downloads.
7 | Close the test window to return to the normal authoring environment.

Once you've set up a test environment incorporating the Bandwidth Profiler, you can open any SWF directly in test mode. The file opens in a player window, using the Bandwidth Profiler and other selected viewing options.

For more information on debugging your movies, see Using the Debugger.

To generate a report listing the amount of data in the final Flash Player file:

1 | Choose File > Publish Settings.
2 | Select Generate Size Report.
3 | Click Publish.
| Flash generates a text file with the extension .txt. (If the movie file is myMovie.fla, the text file is myMovie Report.txt.) The report lists the amount of data in the final Flash Player file by frame.