Re: Logitech QuickCam USB detected by Linux, but not user space applications

[Paul Menzel]

Dear Mauro,


Thank you very much for the quick reply.


On 11/15/18 12:38, Mauro Carvalho Chehab wrote:
> Em Thu, 15 Nov 2018 11:42:32 +0100 Paul Menzel escreveu:

>> I tried to get a Logitech QuickCam USB camera working, but unfortunately, it is 
>> not detected by user space (Cheese, MPlayer).
> 
> Could you please try it with Camorama?
> 
> 	https://github.com/alessio/camorama

Thank you for the suggestion. At first, I only saw a black image, but changing the
resolution made it work. See the status below.

1.  does *not* work

    a)  160x120
    b)  176x144

2.  works

    a)  320x240
    b)  352x288

>> Itâs an old device, so it could be broken, but as itâs detected by the Linux
>> kernel, I wanted to check with you first.
>>
>> Linux 4.18.10 from Debian Sid/unstable is used.
>>
>> ```
>> $ dmesg
>> [â]
>> [ 2891.404361] usb 3-3: new full-speed USB device number 4 using ohci-pci
>> [ 2891.626934] usb 3-3: New USB device found, idVendor=046d, idProduct=092e, bcdDevice= 0.00
>> [ 2891.626945] usb 3-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
>> [ 2891.626951] usb 3-3: Product: Camera
>> [ 2891.626957] usb 3-3: Manufacturer:
>> [ 2893.110249] calling  media_devnode_init+0x0/0x1000 [media] @ 11704
>> [ 2893.110256] media: Linux media interface: v0.10
>> [ 2893.110329] initcall media_devnode_init+0x0/0x1000 [media] returned 0 after 56 usecs
>> [ 2893.210078] calling  videodev_init+0x0/0x79 [videodev] @ 11704
>> [ 2893.210084] videodev: Linux video capture interface: v2.00
>> [ 2893.210123] initcall videodev_init+0x0/0x79 [videodev] returned 0 after 21 usecs
>> [ 2893.333140] calling  gspca_init+0x0/0x1000 [gspca_main] @ 11704
>> [ 2893.333148] gspca_main: v2.14.0 registered
>> [ 2893.333161] initcall gspca_init+0x0/0x1000 [gspca_main] returned 0 after 3 usecs
>> [ 2893.370672] calling  sd_driver_init+0x0/0x1000 [gspca_spca561] @ 11704
>> [ 2893.370751] gspca_main: spca561-2.14.0 probing 046d:092e
>> [ 2893.482675] input: spca561 as /devices/pci0000:00/0000:00:12.0/usb3/3-3/input/input17
>> [ 2893.485415] usbcore: registered new interface driver spca561
>> [ 2893.485434] initcall sd_driver_init+0x0/0x1000 [gspca_spca561] returned 0 after 112054 usecs
>> [â]
>> $ ls -l /dev/video*
>> crw-rw----+ 1 root video 81, 0 Nov 15 09:26 /dev/video0
>>
>> $ mplayer tv:// -tv driver=v4l2:device=/dev/video0
>> MPlayer 1.3.0 (Debian), built with gcc-8 (C) 2000-2016 MPlayer Team
>> do_connect: could not connect to socket
>> connect: No such file or directory
>> Failed to open LIRC support. You will not be able to use your remote control.
>>
>> Playing tv://.
>> TV file format detected.
>> Selected driver: v4l2
>>  name: Video 4 Linux 2 input
>>  author: Martin Olschewski <olschewski@xxxxxxxxxxxxxxxx>
>>  comment: first try, more to come ;-)
>> v4l2: your device driver does not support VIDIOC_G_STD ioctl, VIDIOC_G_PARM was used instead.
>> Selected device: Camera
>>  Capabilities:  video capture  read/write  streaming
>>  supported norms:
>>  inputs: 0 = spca561;
>>  Current input: 0
>>  Current format: unknown (0x31363553)
> 
> The problem is likely here: mplayer is probably not using libv4l2. Without
> that, it can't decode the spca561 specific output format. It is probably
> due to some option used when mplayer was built.

Iâll try to look more into that in the next weeks.

> In the case of Cheese, it uses Gstreamer, with defaults to not use libv4l2
> either. On newest versions of it, there is an environment var that would
> allow enabling it (I don't remember what var).

Thank you for the details. Iâll test that next week.

[â]


Kind regards,

Paul

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