gspca_zc3xx driver produces dark video form webcam.

firewalker · 2010-12-03 10:35:34

The gspca_zc3xx driver in kernel 2.6.36.1 produces a dark video output from the
webcam.

It used to have a very clean and sharp image until now.

And because an image equals to a thousand words:

http://imgur.com/Jie1R.png
http://img337.imageshack.us/img337/3042/zc3xx.png

The webcam I use is:

ID 046d:08af Logitech, Inc. QuickCam Easy/Cool

dmesg:

usb 8-1: new full speed USB device using ohci_hcd and address 4
gspca: probing 046d:08af
zc3xx: probe 2wr ov vga 0x0000
zc3xx: probe sensor -> 0011
zc3xx: Find Sensor HV7131R
input: zc3xx as
/devices/pci0000:00/0000:00:1e.0/0000:02:01.1/usb8/8-1/input/input8
gspca: video0 created

Does anyone else noticed something similar? I have already filled an upstream bug report.

https://bugzilla.kernel.org/show_bug.cgi?id=24242

firewalker · 2010-12-03 20:00:31

The commit that creates the problem is commit 2af0b4c60cc0daf0a3abbaa159380fd729dcf729.

----------------------- GIT bisect -----------------------------------------------

2af0b4c60cc0daf0a3abbaa159380fd729dcf729 is the first bad commit
commit 2af0b4c60cc0daf0a3abbaa159380fd729dcf729
Author: Jean-François Moine <moinejf@free.fr>
Date: Wed Aug 4 07:12:57 2010 -0300

V4L/DVB: gspca - zc3xx: Add the light frequency control for sensor hv7131r

The new exchanges are extracted from the public file lPEPI264v.inf of the
ms-Windows driver. In this file, the sensor is named hv7131b but the exchanges
are those of the hv7131r.

Signed-off-by: Jean-François Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

:040000 040000 97b648701eb35eb594f5023351b0ac4cd1067da3 2b18e38beb6fc32c772168738b8479f81fdaee71 M drivers

----------------------------------------------------------------------------------

Without this commit the webcam works fine.

What should I do now?

wujaklija · 2010-12-06 22:05:00

i have the same problem ... I did not notice until tonight...

firewalker · 2010-12-06 22:45:21

You should build the module without the above commit.

wujaklija · 2010-12-07 18:42:50

done ...

firewalker · 2010-12-07 19:04:46

Does it work?

wujaklija · 2010-12-07 21:48:37

it worked, picture was slightly brighter, but still bad...
Then I downloaded kernel-2.6.35.9 and http://moinejf.free.fr/gspca-2.11.4.tar.gz , took the files zc3xx-reg.h and zc3xx.c from kernel and copied them to extracted gspca folder and made a module from there for gspca_zc3xx ...
picture is now great, as it was before. bad workaround but it works ...

aragats · 2011-01-11 00:11:55

Hi firewalker,

I've trying to add the comment below to the bug you've opened:
https://bugzilla.kernel.org/show_bug.cgi?id=24242
but bugzilla.kernel.org does not work well today. Anyway, posting it here as well:

I've played a little with the latest driver from

http://moinejf.free.fr/gspca-2.11.20.tar.gz

and the old one from 2.6.35.9 kernel.

If I use parameters "from the public file lPEPI264v.inf" in the old driver it behaves as the new one (providing a non-contrast picture) only if I add and refer the structures:

hv7131r_NoFliker, hv7131r_NoFlikerScale,
hv7131r_50HZ, hv7131r_50HZScale,
hv7131r_60HZ, hv7131r_60HZScale

like the new driver does. But removing references to:

hv7131r_NoFliker, hv7131r_NoFlikerScale

makes it to work almost as before with crisp picture, although it takes more time to accommodate the illumination. However, removing those references from the latest driver does not help.

This was just a brief experiment and may give a hint to the developers.

firewalker · 2011-01-11 10:22:35

Thanks for the feed back! Can you make a patch of your changes?

I don;t see any interest of the kernel devs though.

Last edited by firewalker (2011-01-11 10:28:49)

aragats · 2011-01-13 12:19:55

As wujaklija has said above, such patches are just a work around, but I'll do that during this weekend.

By the way, today I've got a personal reply from Jean-Francois Moine (http://moinejf.free.fr):
Thanks for the information. I am a bit busy now, but I will have a look as soon as possible.

So hopefully we eventually will have a real fix in the mainstream.

aragats · 2011-01-18 06:15:59

I've played more with the settings and parameters in the driver and found a couple of useful things.

I used the latest driver from: http://moinejf.free.fr/gspca-2.12.0.tar.gz

1) First of all somehow the quality limits effect the brightness and contrast significantly, so I've changed them back to:

#define QUALITY_MIN 40 // was 50 in the new versions
#define QUALITY_MAX 60 // was 80 in the new versions
#define QUALITY_DEF 50 // was 70 in the new versions

in in zc3xx.c file

2) I've found that for the "default" use of the webcam without any adjustments from user space, the settings in:

static const struct usb_action hv7131r_NoFliker[] (at line #1647 in zc3xx.c of gspca-2.12.0)

are very critical. I've adjusted them to get the old quality, but it still takes longer time to set the autogain etc. Also I do not know much about those settings, I compared them with older driver and used mostly the trial and error method.

Here is the patch file for the latest gspca-2.12.0 version:

http://ingeniware.com/logitech/hv7131r.patch

Again, it's not perfect, but at least provides much better quality. I used "mplayer tv://" to check the webcam image. Also I have submitted these results to the developer Jean-Francois Moine.

synergy_exists · 2011-01-18 15:50:35

I did the same thing that aragats did, removing noflikr/noflikrscale references, but for the SENSOR_GC0303 or SENSOR_GC0305 (im not sure which, i don't have the camera with me). Seemed to work for my cheapo Z-star Microelectronics webcam. I was also using the latest driver (http://moinejf.free.fr/gspca-2.12.0.tar.gz).

aragats · 2011-01-18 18:10:31

Yes, we can just remove the references to noflikr, but that does not solve the problem of much longer accommodation time, which came up after those settings from Windows' .inf file have been included in the driver. It'll be much better to understand how to adjust all the parameters properly - I tried, but it takes too much time to recompile and insert modules after every digit changed. What is the proper way? To implement temporary controls to be used from the user space? I'm not sure...

By the way, how the picture quality can effect the brightness/contrast? It shouldn't happen, that's another problem in the driver.

Last edited by aragats (2011-01-18 18:12:36)

aragats · 2011-01-23 15:52:48

Finally everything works fine! Thanks to Jean-Francois Moine!
Here is the latest version:
http://moinejf.free.fr/gspca-2.12.2.tar.gz
It will appear in 2.6.38 kernel.

firewalker · 2011-01-23 16:28:56

Great news!

aragats · 2011-01-23 18:07:40

With some small bugs fixed:
http://moinejf.free.fr/gspca-2.12.3.tar.gz

firewalker · 2011-02-03 14:07:22

Can someone try gspca-2.12.3.tar.gz? Upgrade to kernel-2.6.37 broke my camera again.

I downloaded http://moinejf.free.fr/gspca-2.12.6.tar.gz an the problem is still there. gspca-2.12.3 had solved it.

firewalker · 2011-02-03 15:08:09

No, false alarm. I could replicate the problem. Again. It was instant.

Arch Linux

#1 2010-12-03 10:35:34

gspca_zc3xx driver produces dark video form webcam.

#2 2010-12-03 20:00:31

Re: gspca_zc3xx driver produces dark video form webcam.

#3 2010-12-06 22:05:00

Re: gspca_zc3xx driver produces dark video form webcam.

#4 2010-12-06 22:45:21

Re: gspca_zc3xx driver produces dark video form webcam.

#5 2010-12-07 18:42:50

Re: gspca_zc3xx driver produces dark video form webcam.

#6 2010-12-07 19:04:46

Re: gspca_zc3xx driver produces dark video form webcam.

#7 2010-12-07 21:48:37

Re: gspca_zc3xx driver produces dark video form webcam.

#8 2011-01-11 00:11:55

Re: gspca_zc3xx driver produces dark video form webcam.

#9 2011-01-11 10:22:35

Re: gspca_zc3xx driver produces dark video form webcam.

#10 2011-01-13 12:19:55

Re: gspca_zc3xx driver produces dark video form webcam.

#11 2011-01-18 06:15:59

Re: gspca_zc3xx driver produces dark video form webcam.

#12 2011-01-18 15:50:35

Re: gspca_zc3xx driver produces dark video form webcam.

#13 2011-01-18 18:10:31

Re: gspca_zc3xx driver produces dark video form webcam.

#14 2011-01-23 15:52:48

Re: gspca_zc3xx driver produces dark video form webcam.

#15 2011-01-23 16:28:56

Re: gspca_zc3xx driver produces dark video form webcam.

#16 2011-01-23 18:07:40

Re: gspca_zc3xx driver produces dark video form webcam.

#17 2011-02-03 14:07:22

Re: gspca_zc3xx driver produces dark video form webcam.

#18 2011-02-03 15:08:09

Re: gspca_zc3xx driver produces dark video form webcam.

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