About Webcam module

shariefbe · 09-11-2009, 02:20 AM

Hi friends,
I have some doubts in video device driver. I have an Creative webcam with me. After inserting the webcam i have seen the following modules installed

Code:

Module              Size       Used by
gspca_zc3xx         55936      0 
gspca_main          29312      1   gspca_zc3xx
videodev            41344      1   gspca_main
v4l1_compat         22404      1   videodev

I dont know which module is exactly for my webcam? i am seeing 5 extra module installed after inserting my webcam. I am confused. Can anyone help me?

ongte · 09-11-2009, 03:04 AM

They all serve some purpose in supporting your webcam.

You can find out what each of them is for, by using modinfo:

Code:

# modinfo -d <modulename>

shariefbe · 09-11-2009, 07:02 AM

See this what i am getting

Code:

sharief@sharief-desktop:~$ modinfo -d gspca_zc3xx
GSPCA ZC03xx/VC3xx USB Camera Driver
sharief@sharief-desktop:~$ modinfo -d gspca_main
GSPCA USB Camera Driver
sharief@sharief-desktop:~$ modinfo -d videodev
Device registrar for Video4Linux drivers v2
sharief@sharief-desktop:~$ modinfo -d v4l1_compat
v4l(1) compatibility layer for v4l2 drivers.
sharief@sharief-desktop:~$

In tis sbove items this "gspca_zc3xx" and "gapca_main" is retrning as camera driver. So i am confused. help me which is correct driver for my camera?

ongte · 09-11-2009, 09:09 PM

Usually they're all required to support your camera. gspca_main is probably the main driver, but this may support many models, so gspca_zc3xx is probably a plug-in to gspca_main that supports your camera specifically.

A framework called v4l(video4linux) is used by most applications to support video capture devices.
videodev & v4l1_compat are used by Linux to create the v4l video device so that it appears as a webcam.

shariefbe · 09-14-2009, 12:57 PM

Here i am facing a new problem. I tried to compile and install the gspca_main and gspca_zc3xx modules separately. I compiled them successfully. but i am getting error when inserting that modules

Code:

root@sharief-desktop:/home/sharief/Desktop/video/gspca# insmod gspca_zc3xx.ko 
insmod: error inserting 'gspca_zc3xx.ko': -1 Unknown symbol in module
root@sharief-desktop:/home/sharief/Desktop/video/gspca# insmod gspca_main.ko 
insmod: error inserting 'gspca_main.ko': -1 Unknown symbol in module

I think this both modules what some other modules to get insert in to kernel...But i am sure about that modules. Can anyone help me?

ongte · 09-15-2009, 12:28 AM

Hmm.. Unknown symbol in module usually means it's not compiled against the right kernel version. Can u double check that you installed kernel source & headers are matching your running kernel?

Anyway, can should use the modprobe command to insert the module instead of insmod.

shariefbe · 09-15-2009, 01:47 AM

No i am using the correct kernel files. I think i have to insert other modules. but i am not sure..correct me if i am wrong

shariefbe · 09-15-2009, 02:24 AM

I cam to know that i need the other two modules to be installed to work this module..ie "videodev" and "v4l1-compat"...so i copiled that modules too...but i am getting the following error..
I compiled all the required modules...ie gspca_main, gspca_zc3xx, v4l1-compat. But i am not getting this "videodev" module..I dont know why...

My Makefile

Code:

obj-m += gspca_main.o
obj-m += gspca_zc3xx.o
obj-m += v4l1-compat.o
obj-m += v4l2-dev.o
obj-m += v4l2-ioctl.o
obj-m += v4l2-device.o
 
gspca_main-objs := gspca.o
gspca_zc3xx-objs := zc3xx.o
videodev-objs := v4l2-dev.o v4l2-ioctl.o v4l2-device.o

all:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules

clean:
make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

if i compile i am getting the the modules as

Code:

sharief@sharief-desktop:~/Desktop/video/gspca$ make
make -C /lib/modules/2.6.30/build M=/home/sharief/Desktop/video/gspca modules
make[1]: Entering directory `/home/sharief/Desktop/kernelroot/linux-2.6.30'
CC [M] /home/sharief/Desktop/video/gspca/gspca.o
CC [M] /home/sharief/Desktop/video/gspca/zc3xx.o
LD [M] /home/sharief/Desktop/video/gspca/gspca_main.o
LD [M] /home/sharief/Desktop/video/gspca/gspca_zc3xx.o
CC [M] /home/sharief/Desktop/video/gspca/v4l1-compat.o
CC [M] /home/sharief/Desktop/video/gspca/v4l2-dev.o
CC [M] /home/sharief/Desktop/video/gspca/v4l2-ioctl.o
CC [M] /home/sharief/Desktop/video/gspca/v4l2-device.o
Building modules, stage 2.
MODPOST 6 modules
CC /home/sharief/Desktop/video/gspca/gspca_main.mod.o
LD [M] /home/sharief/Desktop/video/gspca/gspca_main.ko
CC /home/sharief/Desktop/video/gspca/gspca_zc3xx.mod.o
LD [M] /home/sharief/Desktop/video/gspca/gspca_zc3xx.ko
CC /home/sharief/Desktop/video/gspca/v4l1-compat.mod.o
LD [M] /home/sharief/Desktop/video/gspca/v4l1-compat.ko
CC /home/sharief/Desktop/video/gspca/v4l2-dev.mod.o
LD [M] /home/sharief/Desktop/video/gspca/v4l2-dev.ko
CC /home/sharief/Desktop/video/gspca/v4l2-device.mod.o
LD [M] /home/sharief/Desktop/video/gspca/v4l2-device.ko
CC /home/sharief/Desktop/video/gspca/v4l2-ioctl.mod.o
LD [M] /home/sharief/Desktop/video/gspca/v4l2-ioctl.ko

  I dont know why i am getting like this...?Please help me

I am not getting the exact videodev module....please help me

shariefbe · 09-16-2009, 12:01 PM

Insmod is working fine. But modprobe is not working properly..I know modprobe will install all necessary dependent modules. But in this case all dependent modules are already installed...But i dont know why its happening here..Please help me..see below

Code:

root@sharief-desktop:/home/sharief/Desktop/video/gspca# modprobe v4l1_compat
root@sharief-desktop:/home/sharief/Desktop/video/gspca# modprobe videodev
root@sharief-desktop:/home/sharief/Desktop/video/gspca# modprobe gspca_main
FATAL: Module gspca_main not found.
root@sharief-desktop:/home/sharief/Desktop/video/gspca# modprobe gspca_zc3xx
FATAL: Module gspca_zc3xx not found.
root@sharief-desktop:/home/sharief/Desktop/video/gspca# insmod gspca_main.ko
root@sharief-desktop:/home/sharief/Desktop/video/gspca# insmod gspca_zc3xx.ko
root@sharief-desktop:/home/sharief/Desktop/video/gspca#

Please help me....what will be the error

ongte · 09-17-2009, 08:26 AM

You are loading the module directly from that directory. To use modprobe & to ensure correct operation, you need to copy the .ko files to the appropriate location for kernel modules.
The makefile should have done if for you. Did you run 'make install'?

Anyway, the location should roughly be here:
/lib/modules/$(uname -r)/kernel/drivers/media/video/gspca

shariefbe · 09-18-2009, 12:09 AM

Yes i copied all that to that location. Still it is not working

ongte · 09-19-2009, 10:16 AM

Last thing I can suggest is
# depmod -a

shariefbe · 09-20-2009, 08:57 PM

ok i got...Now its working fine...Thank you