Hi Laurent,
First of all thanks for the reply and the support.
>> Basically when there's not enough
>> light the camera is compensating (very well actually) and the
>> framerate drops to 3fps, when there's daylight it still compensate and
>> the framerate is about 15/20fps (@640x480).
>
> That's quite usual with webcams. Cheap mass market CMOS sensors are not very
> light sensitive and perform quite bad under low light conditions. Increasing
> the exposure time automatically helps but at the cost of image quality (more
> noise, blurry images, ...).
I can confirm that to you. With low light I still get a very good
picture, but the framerate is terribly low (the light compensation
doesn't seem to affect image quality that is always quite good).
>> The odd thing is that sometimes (but I haven't been able to reproduce
>> it) the camera just doesn't use the auto exposure feature when I plug
>> it in and, even if the image is darker, I get constant 30fps.
>
> That's indeed weird. Auto-exposure should be enabled. How many times have you
> encountered the issue ?
I've had this camera for only a few days, but this inconsistent
behaviour showed up only once or twice. Do you know if this camera has
any eprom to save settings? Is it possible that softwares (I tried
skype, mplayer and luvcview) overwrite camera's defaults to put their
settings? This would explain the unconsistent behaviour.
>> Now I would really like to know how to turn off and on the auto
>> exposure and white balance feature of the camera from the driver. If I
>> try to turn off the auto exposure from the luvcview interface, I get
>> "Set Auto Exposure off error" in the standard error.
>
> Your luvcview version might be outdated. Could you try the latest one
> (available from quickcamteam.net) or the uvcdynctrl command line tool (from
> the libwebcam package available on the same website) ?
I'm using luvcview 0.2.4 (latest luvcview ubuntu package).
I compiled the latest uvcdynctrl (0.2) and here is some output:
./uvcdynctrl-0.2 -l
[libwebcam] Unknown V4L2 control ID encountered: 10094849
[libwebcam] Unknown V4L2 control ID encountered: 10094850
[libwebcam] Unknown V4L2 control ID encountered: 10094851
Listing available devices:
video0 UVC Camera (046d:09a4)
./uvcdynctrl-0.2 -c
[libwebcam] Unknown V4L2 control ID encountered: 10094849
[libwebcam] Unknown V4L2 control ID encountered: 10094850
[libwebcam] Unknown V4L2 control ID encountered: 10094851
Listing available controls for device video0:
Exposure, Auto Priority
Exposure (Absolute)
Exposure, Auto
Backlight Compensation
Sharpness
White Balance Temperature
Power Line Frequency
Gain
White Balance Temperature, Auto
Saturation
Contrast
Brightness
./uvcdynctrl-0.2 -cv
[libwebcam] Unknown V4L2 control ID encountered: 10094849
[libwebcam] Unknown V4L2 control ID encountered: 10094850
[libwebcam] Unknown V4L2 control ID encountered: 10094851
Listing available controls for device video0:
Exposure, Auto Priority
ID : 0x00000000,
Type : Boolean,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 1, step size: 1 ],
Default : 0
Exposure (Absolute)
ID : 0x00000000,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 1 .. 10000, step size: 1 ],
Default : 166
Exposure, Auto
ID : 0x00000000,
Type : Choice,
Flags : { CAN_READ, CAN_WRITE },
Values : { 'Auto Mode'[0], 'Manual Mode'[1], 'Shutter Priority
Mode'[2], 'Aperture Priority Mode'[3] },
Default : 3
Backlight Compensation
ID : 0x0000101c,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 2, step size: 1 ],
Default : 1
Sharpness
ID : 0x0000101b,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 255, step size: 1 ],
Default : 240
White Balance Temperature
ID : 0x0000101a,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 10000, step size: 10 ],
Default : 4000
Power Line Frequency
ID : 0x00001018,
Type : Choice,
Flags : { CAN_READ, CAN_WRITE },
Values : { 'Disabled'[0], '50 Hz'[1], '60 Hz'[2] },
Default : 2
Gain
ID : 0x00000003,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 255, step size: 1 ],
Default : 0
White Balance Temperature, Auto
ID : 0x00000009,
Type : Boolean,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 1, step size: 1 ],
Default : 1
Saturation
ID : 0x00000004,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 255, step size: 1 ],
Default : 32
Contrast
ID : 0x00000002,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 255, step size: 1 ],
Default : 32
Brightness
ID : 0x00000001,
Type : Dword,
Flags : { CAN_READ, CAN_WRITE },
Values : [ 0 .. 255, step size: 1 ],
Default : 128
>> And sometimes (often, but not always!) I also get the following in
>> syslog when I plug the cam, but the error doesn't stop the cam from
>> working:
>> Nov 15 14:39:34 greywolf kernel: [11981.960176] uvcvideo: Failed to
>> query (1) UVC control 1 (unit 0) : -110 (exp. 26).
>
> I don't like that one, it reminds me of the Logitech firmware bug that is not
> supposed to happen with that camera :-/
The strange thing is that I usually get this line in syslog only if I
unplug and then replug the camera. the first time I plug it on a clean
boot it doesn't show up.
>> Anyways the camera works even if I get these "soft" errors in syslog.
>
> I would have thought the last error ("Failed to query...") would prevent the
> driver from initialising the camera properly. Could you please show me all
> messages printed by the driver to the kernel log when the problem occurs ?
Ok let's assume that the problem is always present, as the auto
exposure is usually default to on. I made a clean boot of my pc and on
first connection of the camera I get the following syslog:
Nov 16 15:53:10 greywolf kernel: [19593.956048] usb 2-1: new high
speed USB device using ehci_hcd and address 6
Nov 16 15:53:10 greywolf kernel: [19594.199827] usb 2-1: configuration
#1 chosen from 1 choice
Nov 16 15:53:11 greywolf kernel: [19594.799199] Linux video capture
interface: v2.00
Nov 16 15:53:11 greywolf kernel: [19594.877731] uvcvideo: Found UVC
1.00 device <unnamed> (046d:09a4)
Nov 16 15:53:11 greywolf kernel: [19594.892850] input: UVC Camera
(046d:09a4) as /devices/pci0000:00/0000:00:02.1/usb2/2-1/2-1:1.0/input/input7
Nov 16 15:53:11 greywolf kernel: [19594.895354] usbcore: registered
new interface driver snd-usb-audio
Nov 16 15:53:11 greywolf kernel: [19594.896082] usbcore: registered
new interface driver uvcvideo
Nov 16 15:53:11 greywolf kernel: [19594.896089] USB Video Class driver (v0.1.0)
now if I launch luvcview I get a good picture but low framerate (auto
exposure on). Important: I can also confirm that the settings are
saved somewhere because last time I plugged the webcam I tried it with
kopete, and it did screw all the settings giving an awful picture.
Plugging the cam now I got the same crappy output (till I clicked on
"reset to defaults" switch in luvcview).
If I click on "auto exposure off" I still get "Set Auto Exposure off
error" in stderr.
If I unplug and replug the camera I get the following syslog:
Nov 16 16:00:26 greywolf kernel: [20030.102631] usb 2-1: USB
disconnect, address 6
Nov 16 16:00:40 greywolf kernel: [20043.553039] usb 2-1: new high
speed USB device using ehci_hcd and address 7
Nov 16 16:00:40 greywolf kernel: [20043.794369] usb 2-1: configuration
#1 chosen from 1 choice
Nov 16 16:00:40 greywolf kernel: [20043.794860] uvcvideo: Found UVC
1.00 device <unnamed> (046d:09a4)
Nov 16 16:00:40 greywolf kernel: [20043.828903] input: UVC Camera
(046d:09a4) as /devices/pci0000:00/0000:00:02.1/usb2/2-1/2-1:1.0/input/input8
Nov 16 16:00:41 greywolf kernel: [20044.857100] 7:3:1: cannot set freq
16000 to ep 0x86
Nov 16 16:00:41 greywolf kernel: [20045.072108] uvcvideo: Failed to
query (1) UVC control 1 (unit 0) : -110 (exp. 26).
Nov 16 16:00:42 greywolf kernel: [20045.521117] uvcvideo: Failed to
query (1) UVC control 1 (unit 0) : -32 (exp. 26).
Nov 16 16:00:43 greywolf kernel: [20046.521233] uvcvideo: Failed to
query (1) UVC control 1 (unit 0) : -110 (exp. 26).
Nov 16 16:00:44 greywolf kernel: [20047.520218] uvcvideo: Failed to
query (1) UVC control 1 (unit 0) : -110 (exp. 26).
when luvcview runs it uses the following files (I can't see and config
file accessed unfortunately):
COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME
luvcview 13660 chrom cwd DIR 8,3 440 16997
/home/chrom/Desktop/libwebcam-0.1.1
luvcview 13660 chrom rtd DIR 8,2 632 2
/
luvcview 13660 chrom txt REG 8,2 76856 166590
/usr/bin/luvcview
luvcview 13660 chrom DEL REG 0,9 51216433
/SYSV00000000
luvcview 13660 chrom DEL REG 0,9 51183660
/SYSV00000000
luvcview 13660 chrom mem CHR 81,0 279320
/dev/video0
luvcview 13660 chrom mem REG 8,2 33152 164822
/usr/lib/libXcursor.so.1.0.2
luvcview 13660 chrom mem REG 8,2 254076 168440
/usr/lib/locale/en_US.utf8/LC_CTYPE
luvcview 13660 chrom mem REG 8,2 921214 168439
/usr/lib/locale/en_US.utf8/LC_COLLATE
luvcview 13660 chrom mem REG 8,2 25912 164848
/usr/lib/libXrandr.so.2.1.0
luvcview 13660 chrom mem REG 8,2 55772 164828
/usr/lib/libXext.so.6.4.0
luvcview 13660 chrom mem REG 8,2 95676 165979
/usr/lib/libxcb.so.1.0.0
luvcview 13660 chrom mem REG 8,2 971436 164811
/usr/lib/libX11.so.6.2.0
luvcview 13660 chrom mem REG 8,2 14128 164830
/usr/lib/libXfixes.so.3.1.0
luvcview 13660 chrom mem REG 8,2 54 168445
/usr/lib/locale/en_US.utf8/LC_NUMERIC
luvcview 13660 chrom mem REG 8,2 2451 168448
/usr/lib/locale/en_US.utf8/LC_TIME
luvcview 13660 chrom mem REG 8,2 286 168443
/usr/lib/locale/en_US.utf8/LC_MONETARY
luvcview 13660 chrom mem REG 8,2 52 168449
/usr/lib/locale/en_US.utf8/LC_MESSAGES/SYS_LC_MESSAGES
luvcview 13660 chrom mem REG 8,2 34 168446
/usr/lib/locale/en_US.utf8/LC_PAPER
luvcview 13660 chrom mem REG 8,2 77 168444
/usr/lib/locale/en_US.utf8/LC_NAME
luvcview 13660 chrom mem REG 8,2 155 168438
/usr/lib/locale/en_US.utf8/LC_ADDRESS
luvcview 13660 chrom mem REG 8,2 59 168447
/usr/lib/locale/en_US.utf8/LC_TELEPHONE
luvcview 13660 chrom mem REG 8,2 23 168442
/usr/lib/locale/en_US.utf8/LC_MEASUREMENT
luvcview 13660 chrom mem REG 8,2 26040 167059
/usr/lib/gconv/gconv-modules.cache
luvcview 13660 chrom mem REG 8,2 373 168441
/usr/lib/locale/en_US.utf8/LC_IDENTIFICATION
luvcview 13660 chrom mem REG 8,2 34720 162017
/lib/tls/i686/cmov/librt-2.8.90.so
luvcview 13660 chrom mem REG 8,2 116457 162013
/lib/tls/i686/cmov/libpthread-2.8.90.so
luvcview 13660 chrom mem REG 8,2 79736 165024
/usr/lib/libdirect-1.0.so.0.1.0
luvcview 13660 chrom mem REG 8,2 30020 165086
/usr/lib/libfusion-1.0.so.0.1.0
luvcview 13660 chrom mem REG 8,2 412840 165026
/usr/lib/libdirectfb-1.0.so.0.1.0
luvcview 13660 chrom mem REG 8,2 9676 161993
/lib/tls/i686/cmov/libdl-2.8.90.so
luvcview 13660 chrom mem REG 8,2 149332 161995
/lib/tls/i686/cmov/libm-2.8.90.so
luvcview 13660 chrom mem REG 8,2 813216 164926
/usr/lib/libasound.so.2.0.0
luvcview 13660 chrom mem REG 8,2 1425800 161987
/lib/tls/i686/cmov/libc-2.8.90.so
luvcview 13660 chrom mem REG 8,2 426488 164805
/usr/lib/libSDL-1.2.so.0.11.1
luvcview 13660 chrom mem REG 8,2 34352 164850
/usr/lib/libXrender.so.1.3.0
luvcview 13660 chrom mem REG 8,2 16628 164826
/usr/lib/libXdmcp.so.6.0.0
luvcview 13660 chrom mem REG 8,2 7408 164815
/usr/lib/libXau.so.6.0.0
luvcview 13660 chrom mem REG 8,2 5364 165975
/usr/lib/libxcb-xlib.so.0.0.0
luvcview 13660 chrom mem REG 8,2 113252 2342
/lib/ld-2.8.90.so
luvcview 13660 chrom 0u CHR 136,2 4
/dev/pts/2
luvcview 13660 chrom 1u CHR 136,2 4
/dev/pts/2
luvcview 13660 chrom 2u CHR 136,2 4
/dev/pts/2
luvcview 13660 chrom 3u unix 0xc6ac7180 283571 socket
luvcview 13660 chrom 4u unix 0xf568f500 17323 socket
luvcview 13660 chrom 5u unix 0xc6ac6fc0 283573 socket
luvcview 13660 chrom 6u CHR 81,0 279320
/dev/video0
luvcview 13660 chrom 9u unix 0xf50fe380 17376
/tmp/ksocket-chrom/kdeinit4__0
luvcview 13660 chrom 10u unix 0xf568f500 17323 socket
luvcview 13660 chrom 14u unix 0xf568f500 17323 socket
luvcview 13660 chrom 17u unix 0xf568f500 17323 socket
luvcview 13660 chrom 21u unix 0xf568f500 17323 socket
I'm almost sure turning off auto exposure is a matter of finding out
how the cam saves its settings. It's possible that I got the smooth
output just the first time I plugged the cam in (with factory
defaults). the driver can't correctly set back the exposure value, so
the factory setting can't be restored. Also other settings that some
software changes become the default when the cam is plugged back in.
Looking forward to read your impressions.
Mauro
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