Better Webcam Support
Summary
Currently many webcams do not work with Fedora out of the box even though Linux driver exist for them, the intent is to fix this.
Owner
- Name: Hans de Goede
Current status
- Targeted release: Fedora 10
- Last updated: (Sep 16 2008)
- Percentage of completion: 90%
Todo: Patch last batch of v4l2 applications to use libv4l directly instead instead of requiring the LD_PRELOAD hack. The most commonly used applications are already done.
Detailed Description
Webcams not working even though there are Linux drivers has 2 causes:
- The drivers are not in the mainline kernel
- Those drivers that are in the mainline kernel are often v4l2 while many applications will only work with v4l1. Even v4l2 apps often don't work with v4l2 webcam's as the webcams often have camspecific (compressed) pixelformats and most applications don't support all these,
1) Has been largely fixed by working together with gspca upstream to get gspcav2 cleaned up and merged, Linus has merged gspcav2 (through the v4l-dvb subsystem) for 2.6.27, this vastly improves the amount of supported webcams in 2.6.27. I'm currently working on getting the people behind the micromedia driver for the quite popular sonix sn9c20x based cams, to port their driver to a gspca subdriver and move the cam specific format decoding to userspace as was done with all the gspca decoding routines. The plan is to work together with the various upstreams to port any remaining standalone usb webcam drivers to gspca subdrivers, this is a process which will continue after F-10's release.
2) Has been fixed by creating a utility library which contains all the conversion stuff and v4l1 compatibility functions so that applications can easily be modified to work properly with v4l2 webcams, for more info on his library called libv4l, see: http://hansdegoede.livejournal.com/3636.html
Also refer http://kernelnewbies.org/Linux_2_6_26#head-6d4ee1ddea983f5c8ac491b8685a94ea6fa4132b
Benefit to Fedora
Out of the box working hardware makes for happy end users and good reviews.
Scope
This may require temporarily carrying kernel patches if drivers are clearly moving upstream, but not there yet in time for release.
This requires packaging libv4l for v4l1 emulation and format conversion and making modifications to webcam using applications so that they use libv4l.
Test Plan
I currently test with the following webcams:
| Webcam | USB ID | Bridge | Sensor | Status |
|---|---|---|---|---|
| Sweex WC001 | 0c45:6005 | sn9c101 | tas5110 | works |
| Sweex WC004 | 0c45:6011 | sn9c101 | ov6650 | works |
| Qware EasyCam WB-001 | 0c45:6028 | sn9c102 | pas202 | works * |
| Intel Create and Share | 0733:0401 | spca501 | integrated | works |
| Creative Live! VISTA VF0420 | 041e:4064 | ov519 | OV7670 | works |
| Trust WB-1400T | 093a:2468 | pac207 | integrated | works |
| I.T. Works PCW 03 | 093a:2460 | pac207 | integrated | works |
| Logitech QuickCam IM/Connect | 046d:08d9 | zc3xx | HV7131R | works |
| Labtec notebook cam | 046d:08aa | zc3xx | HDCS2020 | works |
| Creative WebCam Vista | 041e:403b | spca561 | integrated | works |
| Logitech QuickCam Express Plus | 046d:092f | spca561 | integrated | works |
| Philips PCVC820K/00 | 05a9:0518 | ov518 | ? | Does not work out of tree driver |
| Philips SPC 200NC | 0471:0325 | zc3xx | PAS106 | works |
| Creative Webcam Pro | 05a9:a511 | ov511 | ? | Does not work out of tree driver |
| I.T. Works notebook cam | 093a:2621 | pac7302 | integrated | works |
| Trust WB-3400T | 093a:260e | pac7311 | integrated | works |
| Dynalink ??? | 06be:d001 | NW208 | integrated | Does not work out of tree driver |
| Sitecom Voicecam | 0c45:62bb | sn0c202 | ov7660 | Does not work out of tree driver |
| Silvercrest Webcam 1.3mpix | eb1a:2820 | eMPIA em28xx | ? | Does not work |
(*) works, but does not work well in low light conditions
Also see here for cams which are supported by gspca and their testing status with the new cleaned up gspcav2.
Tests are done with the following applications:
- xawtv
- cheese
- ekiga
- camorama *
- vlc *
- mplayer *
- skype *
(*) Not in Fedora
User Experience
Out of the box working hardware.
Dependencies
None.
Contingency Plan
Don't ship the drivers / wrapper if they aren't ready.
Documentation
Fedora 10 comes with a much cleaned up and ported to v4l2 version of the gspca webcam driver. Many of the supported webcams produce video data in a manufacturer specific video format, Fedora 10 comes with libv4l which handles conversion of these custom formats to the standard video formats that most applications need. All applications in Fedora have been updateds to use libv4l, so when using applications which are part of Fedora things will just work.
For 3th party applications such as for example skype a compatibility library wrapper has been made available. You can make 32 bits applications use this wrapper by typing the following command in a terminal before starting the application from that same terminal:
export LD_PRELOAD=/usr/lib/libv4l/v4l1compat.so
And then start the application from that same terminal!
For 64 bit applications the command is:
export LD_PRELOAD=/usr/lib64/libv4l/v4l1compat.so
Note that for example skype is a 32 bit applications, so even when running a 64 bit version of Fedora you should use the 32 bit command!
Don't get fooled by the v4l1compat.so name, this library wrapper does not only add v4l1 applicatiom compatibility to v4l2 drivers (such as the new gspca and the uvc driver) but it also handles conversion from cam specific formats to generic video formats for v4l2 applications. If you only want the conversion, without the v4l1 compatibility you can use "v4l2convert.so" instead of v4l1compat.so .
Release Notes
Fedora 10 comes with much improved support for webcams.
Next to improvements to the UVC driver which was first introduced in Fedora 9 and supports any webcam with a vista compliant logo, Fedora 10 also features a brand new v4l2 version of gspca, an usb webcam driver framework with support for many different usb webcam bridges and sensors.
Userspace support for webcams has also been improved by adding libv4l and updating all webcam using applications to use libv4l, this makes these applications understand the often manufacturer specific and custom video formats emitted by many webcams, esp. by many of the webcams supported by gspca.
For a list of all webcams and applications with which Fedora-10's new webcam support has been tested see the BetterWebcamSupport feature page, for a list of all cams supported by the original version of gspca see the original gspca website. The v4l2 version of gspca in Fedora-10 supports all these webcams and more!
Comments and Discussion
See Talk:Features/BetterWebcamSupport