[HOW-TO] Upside-down image from UVC webcam

[Boy1dr]

Skype and most other simular software running directly in Ubuntu, is using the v4l (Video4Linux layer) ... therefore Skype has no issues in regards to flip the cam upside down, using the v4l-settings software.

GMail however is using its own way to connect to the webcam, thereby bypassing the v4l-layer. Therefore the video remains upside down.

In regards to the way the camera is connected...
Most webcams in a laptop are connected through the USB-system ....there are internal connectors as well as external. The webcams obviously are using the internal ones (usual sockets that are available on the motherboard)

[dugh]

There is no horizontal or vertical flip option in the v4l2ucp control panel.

Using an Asus N61J (N61JV)

[HansdeGoede]

Hi All,

It took me a while to fix this problem with my new ASUS K50AF running Lucid (32 Bit Version).
Finally the following approach worked - I hope this description will save you some time:

<snip>

To all: if you fix things this way, please still do the following (as root):
lsusb > lsusb.log
dmidecode > dmi.log

And send me <hdegoede@redhat.com>, a mail with these 2 files attached. Do *NOT* copy and paste them I need them 100% unmodified.

I'll then add your laptop permanently to libv4l's upside down table, so that other people using the same laptop (and you yourself when updating to a newer distro version) don't need to fix things manually, but instead everything will work out of the box!!

Arminho if you communicate with people about this solution please ask them to send their laptop info to me so I can permanently add there model to libv4l's upside down list.

Regards,

Hans de Goede (the libv4l author and maintainer)

[HansdeGoede]

Hello Arjos85
I have tried to launch script you have provided but obtained this message.

zatja@zatja-NB-Ubu:~$ svn checkout svn://svn.berlios.de/linux-uvc/linux-uvc/trunk
svn: No repository found in 'svn://svn.berlios.de/linux-uvc/linux-uvc/trunk'
zatja@zatja-NB-Ubu:~$

Pls, help.
Thanks
Jaromir

Hi,

Please do not use the orginal patch your kernel solution, it:

1) Is very painful to do for you as a user
2) Won't help anyone else with the same laptop model
3) Needs to be redone each kernel update / re-install
4) Will also flip images of any external uvc webcam plugged into your laptop.

Instead you should get the latest libv4l which has a (constantly updated) list of know to have an upside down webcam laptop models. Installation instructions are here:
http://radu.cotescu.com/2009/11/05/f...ubuntu-webcam/

If that does not work your laptop model is not in the list of libv4l, please do (as root):
lsusb > lsusb.log
dmidecode > dmi.log

And send me <hdegoede@redhat.com>, a mail with the 2 generated files attached. Do *NOT* copy and paste them I need them 100% unmodified.

I'll then add your laptop to libv4l's upside down table and get back to you with testing instructions.

Regards,

Hans

[HansdeGoede]

Source down.

svn: No repository found in 'svn://svn.berlios.de/linux-uvc/linux-uvc/trunk'

Hi,

Please do not use the orginal patch your kernel solution, it:

1) Is very painful to do for you as a user
2) Won't help anyone else with the same laptop model
3) Needs to be redone each kernel update / re-install
4) Will also flip images of any external uvc webcam plugged into your laptop.

Instead you should get the latest libv4l which has a (constantly updated) list of know to have an upside down webcam laptop models. Installation instructions are here:
http://radu.cotescu.com/2009/11/05/f...ubuntu-webcam/

If that does not work your laptop model is not in the list of libv4l, please do (as root):
lsusb > lsusb.log
dmidecode > dmi.log

And send me <hdegoede@redhat.com>, a mail with the 2 generated files attached. Do *NOT* copy and paste them I need them 100% unmodified.

I'll then add your laptop to libv4l's upside down table and get back to you with testing instructions.

Regards,

Hans

[HansdeGoede]

svn: No repository found in 'svn://svn.berlios.de/linux-uvc/linux-uvc/trunk'

Source still down. Anyone know of mirror?

Hi,

Please do not use the orginal patch your kernel solution, it:

1) Is very painful to do for you as a user
2) Won't help anyone else with the same laptop model
3) Needs to be redone each kernel update / re-install
4) Will also flip images of any external uvc webcam plugged into your laptop.

Instead you should get the latest libv4l which has a (constantly updated) list of know to have an upside down webcam laptop models. Installation instructions are here:
http://radu.cotescu.com/2009/11/05/f...ubuntu-webcam/

If that does not work your laptop model is not in the list of libv4l, please do (as root):
lsusb > lsusb.log
dmidecode > dmi.log

And send me <hdegoede@redhat.com>, a mail with the 2 generated files attached. Do *NOT* copy and paste them I need them 100% unmodified.

I'll then add your laptop to libv4l's upside down table and get back to you with testing instructions.

Regards,

Hans

[HansdeGoede]

Skype and most other simular software running directly in Ubuntu, is using the v4l (Video4Linux layer) ... therefore Skype has no issues in regards to flip the cam upside down, using the v4l-settings software.

That is not entirely correct the flip functionality for uvc webcams is handled in userspace through libv4l. Most apps shipped with a modern Linux distro use libv4l. For some reason most proprietary apps don't. You don't notice that skype is not using libv4l, as ubunutu ships it with a wrapper script which uses the libv4l provided c-library shim which intercepts the relevant calls and redirects them to libv4l.

GMail however is using its own way to connect to the webcam, thereby bypassing the v4l-layer. Therefore the video remains upside down.

The google video chat plugin is also not using libv4l but accessing the device directly. I've tried contacting google about this, but I've gotten 0 response. Using LD_PRELOAD with the libv4l compat wrapper .so is not really an option here as the plugin gets loaded from firefox.

Please mail google and ask them *kindly* to start using libv4l, also let them know they are free to mail me with any questions at Hans de Goede <hdegoede@redhat.com>

Regards,

Hans (the libv4l author and maintainer)

[HansdeGoede]

There is no horizontal or vertical flip option in the v4l2ucp control panel.

Using an Asus N61J (N61JV)

Hi,

Try using the latest libv4l which has a (constantly updated) list of know to have an upside down webcam laptop models. Installation instructions are here:
http://radu.cotescu.com/2009/11/05/f...ubuntu-webcam/

If that does not work your laptop model is not in the list of libv4l, please do (as root):
lsusb > lsusb.log
dmidecode > dmi.log

And send me <hdegoede@redhat.com>, a mail with the 2 generated files attached. Do *NOT* copy and paste them I need them 100% unmodified.

I'll then add your laptop to libv4l's upside down table and get back to you with testing instructions.

Regards,

Hans

[Dr.C]

Having installed a 'Buntu derivative on my wife's newly-gifted Asus K601 Notebook, I was dismayed when she reported that her Skype image was flipped. Owing to the info obtained from this thread, the problem has been corrected. Thanks for all the help; especially that of Hans de Goede!

My first deliberately employed script reads:
#!/bin/bash
export LIBV4LCONTROL_FLAGS=3
LD_PRELOAD=/usr/lib32/libv4l/v4l1compat.so skype

Happy New Year,
Chard in Oregon

[itsazebra]

Thanks to HansdeGoede, the webcam on my ASUS U3JC "Bamboo" works allright now.
Thank you very much!

Edit: I don't know what's the problem after reboot, but the cam is flipped upside down again (in skype)... Has anybody an idea what went wrong ?

Regards,
itsazebra.