Unable to achieve 30fps using 'read()' in C

Unable to achieve 30fps using 'read()' in C

[wei kin]

Hi all, I am new in v4l programming. What I did in my code is I used 'read( )' in C programming to read images from my Logitech Quickcam Express. My problem is I can't get 30frames per second, what I got is just 5fps when I loop and read for 200times. Do anyone know why is it under performance? Thanks

Rgds,
nik2031



      
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RE: Unable to achieve 30fps using 'read()' in C

[Jonathan Lafontaine]

Is your webcam is connected to a usb2 port(if it requires)?

Do lsusb

And dmesg | grep usb

dmesg | grep Logitech

which driver r u using for v4l2

-----Original Message-----
From: video4linux-list-bounces@redhat.com [mailto:video4linux-list-bounces@redhat.com] On Behalf Of wei kin
Sent: 28 novembre 2008 03:03
To: video4linux-list@redhat.com
Subject: Unable to achieve 30fps using 'read()' in C

Hi all, I am new in v4l programming. What I did in my code is I used 'read( )' in C programming to read images from my Logitech Quickcam Express. My problem is I can't get 30frames per second, what I got is just 5fps when I loop and read for 200times. Do anyone know why is it under performance? Thanks

Rgds,
nik2031




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Re: Unable to achieve 30fps using 'read()' in C

[Jackson Yee]

Wei,

You will only get half rate or worse using read() because there is no
buffer queue for the frames. Please use streaming IO to get all of the
frames that your device produces as in the API example:

http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec/a16706.htm

Regards,
Jackson Yee
The Possum Company
540-818-4079
me@gotpossum.com

On Fri, Nov 28, 2008 at 3:02 AM, wei kin <kin2031@yahoo.com> wrote:
> Hi all, I am new in v4l programming. What I did in my code is I used 'read( )' in C programming to read images from my Logitech Quickcam Express. My problem is I can't get 30frames per second, what I got is just 5fps when I loop and read for 200times. Do anyone know why is it under performance? Thanks
>
> Rgds,
> nik2031

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Re: Unable to achieve 30fps using 'read()' in C

[wei kin]

I installed qc-usb-0.6.6 and gspca-modules-2.6.18-5-xen-686 in my debian 2.6.18-5-xen. Below are what I got:

lsusb
Bus 004 Device 004: ID 046d:0920 Logitech, Inc. QuickCam Express

dmesg | grep usb
usbcore: registered new driver usbfs
usbcore: registered new driver hub
usb usb1: configuration #1 chosen from 1 choice
usb usb2: configuration #1 chosen from 1 choice
usb usb3: configuration #1 chosen from 1 choice
usb usb4: configuration #1 chosen from 1 choice
usb 4-1: new full speed USB device using uhci_hcd and address 2
usb 4-1: configuration #1 chosen from 1 choice
usb usb5: configuration #1 chosen from 1 choice
 sda:<6>usb 4-1: USB disconnect, address 2
usb 4-1: new full speed USB device using uhci_hcd and address 3
usb 4-1: configuration #1 chosen from 1 choice
usbcore: registered new driver gspca
usb 4-1: USB disconnect, address 3
usb 4-1: new full speed USB device using uhci_hcd and address 4
usb 4-1: configuration #1 chosen from 1 choice

dmesg | grep Logitech
input: ImPS/2 Logitech Wheel Mouse as /class/input/input2

I did try out the API example in http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec/a16706.htm. However, I get error message stated that  '/dev/video0 is no V4L2 device'.

Do anyone have any idea?
Thanks,
Rgds
nik2031

On Fri, Nov 28, 2008 at 3:02 AM, wei kin <kin2031@yahoo.com> wrote:
>
Hi all, I am new in v4l programming. What I did in my code is I used
'read( )' in C programming to read images from my Logitech Quickcam
Express. My problem is I can't get 30frames per second, what I got is
just 5fps when I loop and read for 200times. Do anyone know why is it
under performance? Thanks
>
> Rgds,
> nik2031




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Re: Unable to achieve 30fps using 'read()' in C

[Jean-Francois Moine]

On Sat, 2008-11-29 at 00:27 -0800, wei kin wrote:
> I installed qc-usb-0.6.6 and gspca-modules-2.6.18-5-xen-686 in my debian 2.6.18-5-xen. Below are what I got:
> 
> lsusb
> Bus 004 Device 004: ID 046d:0920 Logitech, Inc. QuickCam Express
> 
> dmesg | grep usb
> usbcore: registered new driver usbfs
> usbcore: registered new driver hub
> usb usb1: configuration #1 chosen from 1 choice
> usb usb2: configuration #1 chosen from 1 choice
> usb usb3: configuration #1 chosen from 1 choice
> usb usb4: configuration #1 chosen from 1 choice
> usb 4-1: new full speed USB device using uhci_hcd and address 2
> usb 4-1: configuration #1 chosen from 1 choice
> usb usb5: configuration #1 chosen from 1 choice
>  sda:<6>usb 4-1: USB disconnect, address 2
> usb 4-1: new full speed USB device using uhci_hcd and address 3
> usb 4-1: configuration #1 chosen from 1 choice
> usbcore: registered new driver gspca
> usb 4-1: USB disconnect, address 3
> usb 4-1: new full speed USB device using uhci_hcd and address 4
> usb 4-1: configuration #1 chosen from 1 choice
> 
> dmesg | grep Logitech
> input: ImPS/2 Logitech Wheel Mouse as /class/input/input2
> 
> I did try out the API example in http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec/a16706.htm. However, I get error message stated that  '/dev/video0 is no V4L2 device'.
> 
> Do anyone have any idea?

You use the gspca v1 which is not v4l2 compliant. Please, switch to
gspca v2 (look at my web page). Note that for your webcam, the subdriver
has some remaining problems. I hope to fix them soon.

Regards.

-- 
Ken ar c'hentañ |             ** Breizh ha Linux atav! **
Jef             |               http://moinejf.free.fr/


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Re: Unable to achieve 30fps using 'read()' in C

[wei kin]

Hi guys, thanks for the advice. However, after I install gspca v2 and run the API example in http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec/a16706.htm, I still get only 5fps. I am still wondering how others manage to get higher fps. Or do I need other programming technique such as thread programming to achieve that?

Thanks.
Rgds,
nik2031

On Sat, 2008-11-29 at 00:27 -0800, wei kin wrote:
> I installed qc-usb-0.6.6 and gspca-modules-2.6.18-5-xen-686 in my debian 2.6.18-5-xen. Below are what I got:
> 
> lsusb
> Bus 004 Device 004: ID 046d:0920 Logitech, Inc. QuickCam Express
> 
> dmesg | grep usb
> usbcore: registered new driver usbfs
> usbcore: registered new driver hub
> usb usb1: configuration #1 chosen from 1 choice
> usb usb2: configuration #1 chosen from 1 choice
> usb usb3: configuration #1 chosen from 1 choice
> usb usb4: configuration #1 chosen from 1 choice
> usb 4-1: new full speed USB device using uhci_hcd and address 2
> usb 4-1: configuration #1 chosen from 1 choice
> usb usb5: configuration #1 chosen from 1 choice
>  sda:<6>usb 4-1: USB disconnect, address 2
> usb 4-1: new full speed USB device using uhci_hcd and address 3
> usb 4-1: configuration #1 chosen from 1 choice
> usbcore: registered new driver gspca
> usb 4-1: USB disconnect, address 3
> usb 4-1: new full speed USB device using uhci_hcd and address 4
> usb 4-1: configuration #1 chosen from 1 choice
> 
> dmesg | grep Logitech
> input: ImPS/2 Logitech Wheel Mouse as /class/input/input2
> 
> I did try out the API example in http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec/a16706.htm. However, I get error message stated that  '/dev/video0 is no V4L2 device'.
> 
> Do anyone have any idea?



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Re: Unable to achieve 30fps using 'read()' in C

[Nicolas]

Hi,

With my driver stk11xx 
http://syntekdriver.sourceforge.net

I can read a V4L (1/2) stream with read or map access.

I can reache 30 fps. (with the device 174f:a311)

Regards,

Nicolas

Le samedi 29 novembre 2008 à 21:26 -0800, wei kin a écrit :
> Hi guys, thanks for the advice. However, after I install gspca v2 and run the API example in http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec/a16706.htm, I still get only 5fps. I am still wondering how others manage to get higher fps. Or do I need other programming technique such as thread programming to achieve that?
> 
> Thanks.
> Rgds,
> nik2031
> 
> On Sat, 2008-11-29 at 00:27 -0800, wei kin wrote:
> > I installed qc-usb-0.6.6 and gspca-modules-2.6.18-5-xen-686 in my debian 2.6.18-5-xen. Below are what I got:
> > 
> > lsusb
> > Bus 004 Device 004: ID 046d:0920 Logitech, Inc. QuickCam Express
> > 
> > dmesg | grep usb
> > usbcore: registered new driver usbfs
> > usbcore: registered new driver hub
> > usb usb1: configuration #1 chosen from 1 choice
> > usb usb2: configuration #1 chosen from 1 choice
> > usb usb3: configuration #1 chosen from 1 choice
> > usb usb4: configuration #1 chosen from 1 choice
> > usb 4-1: new full speed USB device using uhci_hcd and address 2
> > usb 4-1: configuration #1 chosen from 1 choice
> > usb usb5: configuration #1 chosen from 1 choice
> >  sda:<6>usb 4-1: USB disconnect, address 2
> > usb 4-1: new full speed USB device using uhci_hcd and address 3
> > usb 4-1: configuration #1 chosen from 1 choice
> > usbcore: registered new driver gspca
> > usb 4-1: USB disconnect, address 3
> > usb 4-1: new full speed USB device using uhci_hcd and address 4
> > usb 4-1: configuration #1 chosen from 1 choice
> > 
> > dmesg | grep Logitech
> > input: ImPS/2 Logitech Wheel Mouse as /class/input/input2
> > 
> > I did try out the API example in http://www.linuxtv.org/downloads/video4linux/API/V4L2_API/spec/a16706.htm. However, I get error message stated that  '/dev/video0 is no V4L2 device'.
> > 
> > Do anyone have any idea?
> 
> 
>       
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-- 
Nicolas VIVIEN

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