LinuxTVWiki - User contributions [en]

Libv4l Upside Down Webcams

2012-10-01T20:12:11Z

Upsidedown: /* Ubuntu Precise */

This page is supposed to give guidance if the webcam image is displayed upside down.

= Upgrading libv4l package to latest stable =

The upside down table included in libv4l gets updated with new laptop / webcam combinations that also suffer the upside down webcam problem. Although it's possible to compile and instal a newer libv4l by hand, installing an updated distribution package is preferable.

A good hint if it's worth to upgrade libv4l is to run the qv4l2 program from v4l-utils. If the image there is correct, there is no need to upgrade. If it's upside down, upgrading is a good idea.

== Ubuntu ==

Add the stable libv4l PPA and upgrade packages:
apt-add-repository ppa:libv4l/stable
apt-get update
apt-get upgrade

= Fix upside down webcams in Skype =

To fix the upside down camera problem for most Skype users it's necessary to preload the v4l1convert library. This can be either done from the command line or more convenient by editing the skype.desktop file.

== Ubuntu Precise ==

Because Skype is a 32bit binary one needs to install the 32bit libv4l-0 package:
dpkg --add-architecture i386
apt-get update
apt-get install libv4l-0:i386

Edit /usr/share/applications/skype.desktop and replace the Exec line with:
Exec=sh -c 'LD_PRELOAD=/usr/lib/i386-linux-gnu/libv4l/v4l1compat.so skype'

Libv4l Upside Down Webcams

2012-08-19T12:03:17Z

Upsidedown:

This page is supposed to give guidance if the webcam image is displayed upside down.

= Upgrading libv4l package to latest stable =

The upside down table included in libv4l gets updated with new laptop / webcam combinations that also suffer the upside down webcam problem. Although it's possible to compile and instal a newer libv4l by hand, installing an updated distribution package is preferable.

A good hint if it's worth to upgrade libv4l is to run the qv4l2 program from v4l-utils. If the image there is correct, there is no need to upgrade. If it's upside down, upgrading is a good idea.

== Ubuntu ==

Add the stable libv4l PPA and upgrade packages:
apt-add-repository ppa:libv4l/stable
apt-get update
apt-get upgrade

= Fix upside down webcams in Skype =

To fix the upside down camera problem for most Skype users it's necessary to preload the v4l1convert library. This can be either done from the command line or more convenient by editing the skype.desktop file.

== Ubuntu Precise ==

Because Skype is a 32bit binary one needs to install the 32bit libv4l-0 package:
apt-get install libv4l-0:i386

Edit /usr/share/applications/skype.desktop and replace the Exec line with:
Exec=sh -c 'LD_PRELOAD=/usr/lib/i386-linux-gnu/libv4l/v4l1compat.so skype'

Libv4l Upside Down Webcams

2012-08-19T11:56:29Z

Upsidedown: Created page with "This page is supposed to give guidance if the webcam image is displayed upside down. = Upgrading libv4l package to latest stable = The upside down table included in libv4l gets..."

This page is supposed to give guidance if the webcam image is displayed upside down.

= Upgrading libv4l package to latest stable =

The upside down table included in libv4l gets updated with new laptop / webcam combinations that also suffer the upside down webcam problem. Although it's possible to compile and instal a newer libv4l by hand, installing an updated distribution package is preferable.

A good hint if it's worth to upgrade libv4l is to run the qv4l2 program from v4l-utils. If the image there is correct, there is no need to upgrade. If it's upside down, upgrading is a good idea.

== Ubuntu ==

Add the stable libv4l PPA:
<code>apt-add-repository ppa:libv4l/stable</code>

Update package lists
<code>apt-get update</code>

Update packages
<code>apt-get upgrade</code>

= Fix upside down webcams in Skype =

To fix the upside down camera problem for most Skype users it's necessary to preload the v4l1convert library. This can be either done from the command line or more convenient by editing the skype.desktop file.

== Ubuntu Precise ==

Install 32bit libv4l-0 package:
<code>apt-get install libv4l-0:i386</code>

Edit /usr/share/applications/skype.desktop and replace the Exec line with:
<code>Exec=sh -c 'LD_PRELOAD=/usr/lib/i386-linux-gnu/libv4l/v4lcompat.so skype'</code>

Developer Section

2012-08-19T10:29:57Z

Upsidedown:

__NOTOC__
__NOEDITSECTION__
<div style="margin:0; border:1px solid #6289AB; padding:0.5em; background-color:#F7F9FB;">
{| style="background-color:#F7F9FB;" cellspacing=0 cellpadding=5 border=0
| valign=top | [[Image:Developer_icon.png|50px|]]
|
=='''[[Developer Section]]:'''==
|}

<div style="border: solid 1px; border-color: blue; margin: 1em; padding: 0.5em; background-color: Lavender;">
<center>"Anyone who has never made a mistake has never tried anything new." - Albert Einstein</center>
</div>

{|valign=top cellpadding=0 cellspacing=0 width=100%

|valign=top bgcolor=#F7F9FB width=32%|
'''Development Repositories:'''<br>
* ''Git Repos''
** [http://git.linuxtv.org/media_tree.git Git V4L-DVB development repository]
** [http://git.linuxtv.org/ A list of LinuxTV hosted Git development repositories]
** [http://www.kernel.org/git/gitweb.cgi?p=linux/kernel/git/mchehab/v4l-dvb.git;a=log Current git log]
** [[Maintaining Git trees]]
** [[Using a git driver development tree]]
* ''Mercurial (Hg) Repos''
** [http://linuxtv.org/hg/v4l-dvb Mercurial V4L-DVB backport repository]
** [http://linuxtv.org/hg/ A list of LinuxTV hosted Mercurial development repositories]
** [[Maintaining Mercurial (Hg) trees]]

|valign=top bgcolor=#F7F9FB width=4%|
|valign=top bgcolor=#F7F9FB width=32%|
'''Kernel Driver Development:''' <br>

* [http://jungla.dit.upm.es/%7Ejmseyas/linux/kernel/hackers-docs.html Linux kernel development documentation index]
* ''Application Programming Interface (API):''
** [[Development: Linux Media Infrastructure API|Linux Media Infrastructure API]]
* ''Drivers:''
** [[Anatomy of a V4L driver]]
** [[Anatomy of a DVB driver]]
** [[Development: How to add support for a device|How to add support for a device]]
** [[Development: How to develop drivers for USB based devices|How to develop drivers for USB based devices]]
*** [[DVB via USB|General Information Regarding DVB via USB]]
*** [[Development: Reverse Engineering USB Webcams|Reverse Engineering USB Webcams]]
** [[Bus snooping/sniffing]]
** [[Development: How to extract a firmware|How to extract a firmware]]
** [[Development: Hints for Refactoring Existing Drivers|Hints for Refactoring Existing Drivers]]
* ''Submitting Your Work:''
** [[Development: Coding Style|Coding Style]]
** [[Development: Code Review|Invitation for Code Review]]
** [[Development: How_to_submit_patches |How to submit patches]]
*** [[Development: Submitting Patches|Rules for submitting patches]]
*** [[Development: Linux Kernel patch submittal checklist|Linux Kernel patch submittal checklist]]
*** [[Development: Submitting Drivers|Rules for submitting drivers]]

|valign=top bgcolor=#F7F9FB width=4%|
|valign=top bgcolor=#F7F9FB width=32%|
'''Development Miscellanea:'''
* [[Development: The DVB Decoder Challenge|The DVB Decoder Challenge]]
* [[TODO - main tasks]]
* [[V4L Test Suite]]
* [[V4L framework progress]]
* [[Libv4l Progress]]
* [[Libv4l Upside Down Webcams]]

'''Userspace Development:'''<br>
* [[V4L2 Userspace Library]]

|}
</div>