Why xawtv produces some error messages on startup?
That’s because xawtv was designed primarily for video capture cards (TV tuners). These cards have their own processor, unlimited bandwidth of PCI bus and have their own Linux driver (like bttv). xawtv sends some illegal requests to USB camera driver. The driver correctly rejects those requests, this explains some of visible error messages. Other messages are caused by xawtv “probing” the driver in order to find out what video formats (palettes) it supports, what video sizes etc. During probing errors do not cause any harm; instead xawtv just notes that this driver does or does not support a given set of parameters. After probing is complete xawtv switches to the most appropriate mode that is supported by the driver.
