User`s guide

Hardware Recommendations
Universal Serial Bus (USB)
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Wirecast User Guide | 104730
computer, but they are often all connected to the same bus. You have to add a separate
FireWire card to increase the bandwidth.
Bandwidth Use
If you have a hard disk connected to a FireWire hub and also have a camera connected
to the same hub, it may appear to work but the bus can still become saturated. For
example, when new email arrives and your email program accesses a file on your
FireWire drive, it can cause FireWire saturation.
Be mindful of this limitation when connecting hardware to your computer. Just
because your setup works when you first put it together does not mean it will always
work. Experiment with your setup and make sure that you have enough FireWire
bandwidth to share all of your devices without experiencing choppy video.
Normally, a camera requires around 25 Mbps to deliver audio and video to Wirecast.
However, some cameras may require 100 Mbps or more.
Universal Serial Bus (USB)
Many cameras use USB instead of FireWire to connect to the computer, and the same
bandwidth problems apply to USB connections. Keep as few devices on the bus as
possible to prevent saturation, and keep in mind that even if you have multiple USB
sockets they are often attached to the same USB bus. The USB devices dialog can be
used to identify devices sharing a bus or buses with available ports. Standard USB
supports up to 12 Mbps and high-speed USB supports up to 480 Mbps.
High Definition (HDV)
Always use the best quality camera you can get. Even if your viewers are only going to
see 176×144 (G3 Mobile) an HDV camera is going to give you much better quality than
a USB camera.
Although you can achieve extremely high quality video using HDV, there are some
limitations in using it. Most of these limitations are due to resource consumption. Even
if you have multiple busses, to use more than one HDV camera with Wirecast you need
a high-end (fast and powerful) computer. HDV images are so large they stress all
components involved in your production (memory, video memory, video fill rate,
bandwidth, etc.).
HDV Cameras in DV Mode.
If you only have HDV cameras, and you need to use several cameras, put your
secondary cameras in DV mode. This saves bandwidth. When you switch your HDV
camera to DV mode, your camera acts like a DV camera. Although you do not get HDV
quality, you get much higher quality than your average DV camera because most HDV
cameras have very high quality CCD elements in them.