Video capture from webcam with USB passthrough freezes
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
QEMU |
Expired
|
Undecided
|
Unassigned |
Bug Description
QEMU version: 1.2.0
Graphics: Spice
Guest: Windows 7 32-bit
Host: Ubuntu 12.10 amd64 (using distro package qemu-kvm-spice)
I am using USB 2.0 passthrough of a Logitech C920 webcam. The guest is running the proprietary Logitech drivers. When video chatting with either Google+ Hangouts or Skype 3.8.0.115, video capture from the webcam is initially fine but eventually freezes. It remains frozen for up to several minutes and then resumes on its own. The process then repeats. Audio recorded from the webcam's mic works continuously.
The problem also affects video recording in Logitech's bundled software. Strangely though, the live preview is _not_ affected. The freezing is only present in the recorded video file.
I can tell that the problem is not introduced by Spice during playback, because the user on the other end of Hangouts/Skype sees the same problem, and the freezes in a recorded video file are seen at the same point every time the file is played.
Command line:
/usr/bin/kvm-spice -name Windows7 -S -M pc-1.0 -enable-kvm -m 2048 -smp 3,sockets=
The problem also occurs with the generic Microsoft webcam drivers.
Note that, during webcam use, these messages are output from QEMU sporadically:
USBDEVFS_ DISCARDURB: Invalid argument DISCARDURB: Invalid argument DISCARDURB: Invalid argument DISCARDURB: Invalid argument DISCARDURB: Invalid argument DISCARDURB: Invalid argument DISCARDURB: Invalid argument DISCARDURB: Invalid argument DISCARDURB: Invalid argument
USBDEVFS_
husb: leaking iso urbs because of discard failure
USBDEVFS_
USBDEVFS_
husb: leaking iso urbs because of discard failure
USBDEVFS_
USBDEVFS_
husb: leaking iso urbs because of discard failure
USBDEVFS_
USBDEVFS_
USBDEVFS_
husb: leaking iso urbs because of discard failure
However, the timing of the messages is completely uncorrelated with the video freezes, so I am uncertain as to whether they are related or not.