Operation Manual

"Set Custom Dimensions" box to set whatever dimensions you want.
A few things to remember when setting custom dimensions: height and width must both be even multiples of four, or
DirectShow will refuse
to render. If the dimensions you choose are too large, DirectShow may not have enough memory to render the video.
And if you choose dimensions with a different aspect ratio than your original videos, the resulting video may look
stretched or squashed. [Note to Joseph: once I'm able to get a custom resizer filter working, the aspect ratio issue
should go away, so we'll have to edit this bit.]
Frame Rate:
This area lets you specify your video's frame rate (how many frames per second the video will contain). By default, it'll
be set to the highest frame rate found among the video clips in your project. (To learn what a video's native frame rate
is, right-click on the video clip and select the "Properties" option from the menu that pops up.) The Frame Rate combo
box contains a variety of standard frame rates, but if it's missing the one you want, you can check the "Set a custom
frame rate" box to type in a specific frame rate.
Should I change the default frame rate?
Probably not. Increasing the frame rate to one higher than the frame rates found in any of your project's video clips will
typically increase the size of
the video file without increasing quality, while decreasing the frame rate will usually lower the quality. Even if your
primary concern is
video size, changing the frame rate is not necessarily useful; depending on the encoding method you choose,
lowering the frame rate can actually increase file size. If you're trying to alter the frame rate to produce smaller file
sizes, you'll need to experiment to find the best setting.
Video Bit Rate:
This setting specifies approximately how much bandwidth your video will require, in kilobits per second. It's one of the
primary factors affecting compression. Higher bit rates mean larger files and higher quality, while lower bit rates will
result in smaller, lower quality video files. The right bit rate to use will depend on the dimensions and frame rate of
your video; a bit rate that produces a high quality 720 x 480 video may result in a grainy, pixilated video if you use it
for a 1440 x 1080 video. You may need to experiment to find the results you like best for different types of video.
Video Encoding Method: Microsoft provides a handful of encoding methods for WMV creation. Which one to use will
depend on your priorities - quality or file size - and on your video content. In practice, an encoding method that
produces the best results for one video may not produce the best results for another, so you'll have to experiment if
you want the absolute best results for each project.
Constant Bit Rate (one pass): This method was designed to handle live streaming video, and will usually produce
the lowest quality results when rendering to a file. Because it's a one-pass method, though, it takes half as long to
render out to file as the two-pass methods, so it might be the choice for you if the world's ending in a few minutes and
you really want to be able to watch this video before you go.
Constant Bit Rate (two pass): This method will usually produce good quality video if you've set a sufficiently high bit
rate. Because it's a two-pass method, it'll take twice as long to create the video as one-pass methods will. Since the
bit rate will be consistent for the entire video, it should work well for videos that you intend to stream over a network or
the internet.
Variable Bit Rate with Quality Setting: Using this encoding method with the quality slider at its highest setting
usually results in higher quality videos than any of the other encoding methods. However, the resulting video files tend
to be about three times larger, as well. Use this method if quality is absolutely the highest priority. This is a one-pass
encoding method, which means it will take roughly half as long to create the video as with two-pass methods. (The
number of passes refers only to the creation of the video, and doesn't affect the speed of video playback.)
Variable Bit Rate with Bit Rate Ceiling: This two-pass method uses a variable bit rate, which means that it's likely
(but not guaranteed) to produce smaller file sizes than the constant-bit-rate methods. With variable bit rate encoding,
the bit rate you choose will be the average bit rate, but actual bit rate during playback may vary depending on how
complex the video is. (Sections of video with lots of motion will probably have a higher bit rate, and sections with little
motion will have lower rates.) This method has a max rate ceiling, which means that it'll keep the highest bit rates from
being much higher than the average bit rate. Consequently, this method will work better for streaming than the
Unconstrained Variable Bit Rate method, but may not produce video of quite as high a quality.