If you use the module parameter 'flags=8' you will see output resembling this:
The first thing you notice is the horizontal bar across the top. This is a representation of the amount of data contained within the camera's video buffer.
On the left side, there are several numbers with two-letter codes associated with each. These codes are part of the usbvideo driver. The codes represent the following:
| FR | Number of frames decoded. |
| UC | URB count - how many URBs have been received. |
| UL | URB length - normal URB length? |
| DC | Data count - how much data has been received. |
| HC | Header count - how many headers have been decoded. |
| IS | Iso skip count - how many iso frames we have skipped. |
| IE | Iso error count - how many iso errors we have encountered. |
| CO | Color - current V4L color setting |
| HU | Hue - current V4L hue setting |
| BR | Brightness - current V4L brightness setting |
| PI | Contrast - current V4L contrast setting |
| WH | Whiteness - current V4L whiteness setting |
The right side contains several codes specific to the ultracam driver. They are:
| WB | Current white balance setting (range: 0 to 48) |
| R | Average red value |
| G | Average green value |
| B | Average blue value |
| Y | Average y (brightness) value |
The RGB values can help in debugging the auto white balance code. As you can see here, the picture has a definite red tinge to it, with a high white balance value. Since it is set to auto-whitebal, eventually the white balance level will come down to a more reasonable, and less red value.