Before encoding you need to select a variety of settings including the following: input and output filenames; output video dimensions; video and SWF frame rate, bit rate, and keyframe options; image quality; and audio sampling rates and bit rates (see Figure 4).
Figure 4 Encoding options in the Vid/Aud tab
At this point you can save time by selecting a preset. Presets save time because Flix Pro fills in all these required encoding options for you. On the other hand, presets limit your output options.
Flix comes with a video presets for four bandwidths: 56K, 300K, 512K, and 1,000K. Usually, you will want to encode two versions of your videos: once for viewers accessing your video on a dialup modem (56K) and one for viewers on a broadband connection (300K or 512K). These are further divided into groups for Flash MX SWF, Flash MX FLV, Flash 3+ SWF and vector video SWF output. Flix also includes audio-only output presets (see Figure 4).
Figure 5 Flix Pros’s video encoding presets
These presets provide simple, three-click encoding—browse to your source video, select a preset and click encode. But if you do use the presets regularly, there are a couple of issues you should watch out for:
- Flash SWF video has two frame rates: the video frame rate, which is the
number of distinct video frames per second in your video; and the SWF frame
rate, which is the number of SWF frames in your final Flash video. These frame
rates are not the same, and you have to keep track of both. Flash SWF video is
different in this way because standard video has only a single frame rate to
worry about. The issue here is that the Flix presets automatically set both
frame rates to 30 fps, which might not yield the best playback if your source
video uses a different frame rate.
On2 recommends that you set video frame rate to a factor of your source video frame rate. A factor is a number that divides evenly (without a remainder) into another number. For example 1, 2, 3, and 6 are factors of 6. Also, the SWF frame rate must be equal to or a multiple of your Flix video frame rate (see Figure 6).
Flash FLV video uses only one frame rate - a video frame rate, so no worries here.
- The default image dimensions are based on aspect ratios of 3:2. However, if your source video uses a different aspect ratio, such as widescreen format (16:9), the video will look stretched when encoded using the default settings. To avoid this, select the Maintain Aspect Ratio option in the Video Dimensions section of the Vid/Aud tab (see Figure 6).
Figure 6 Encoding options in the Vid/Aud tab
If you are encoding to SWF, Flix can output the HTML code required to play your output video SWF file in a Web page. Accomplish this by checking the Export HTML box in the HTML tab (see Figure 7).
Figure 7 Encoding options in the HTML tab