Re: uvideo not wrok fine

From: Nilton Jose Rizzo <rizzo_at_rizzo.eng.br>
Date: Sun, 19 Jul 2026 17:03:20 UTC
Em 19/07/2026 13:49, Baptiste Daroussin escreveu:
>
> Le 18 juillet 2026 23:45:58 GMT+02:00, Nilton Jose Rizzo<rizzo@rizzo.eng.br> a écrit :
>> Em 18/07/2026 02:36, Baptiste Daroussin escreveu:
>>> Le 14 juillet 2026 01:42:07 GMT+02:00, Nilton Jose Rizzo<rizzo@rizzo.eng.br> a écrit :
>>>> Hi all,
>>>>
>>>> I upgraded my desktop last weekend and decided to try the new *uvideo*driver from OpenBSD.
>>>>
>>>> When I run |pwcview|, the image is displayed incorrectly: it is horizontally duplicated and shows interlaced lines.
>>>>
>>>> If I switch back to |webcamd|, the webcam works normally.
>>>>
>>>> I also tested it with *Google Meet*and *Jitsi Meet*in Firefox.
>>>>
>>>> On Google Meet, I receive a warning indicating that my webcam is not functioning properly.
>>>>
>>>> Has anyone experienced this issue or have any suggestions on how to troubleshoot it?
>>>>
>>>> My web cam is HD Pro C920 USB
>>>>
>>>> ugen0.2: <HD Pro Webcam C920 Logitech, Inc.> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)
>>>>
>>>> $ usbconfig -v -d ugen0.2
>>>> ugen0.2: <HD Pro Webcam C920 Logitech, Inc.> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)
>>>> ugen0.2.2: uaudio0: <vendor 0x046d HD Pro Webcam C920, class 239/2, rev 2.00/0.11, addr 3>
>>>>
>>>>     bLength = 0x0012
>>>>     bDescriptorType = 0x0001
>>>>     bcdUSB = 0x0200
>>>>     bDeviceClass = 0x00ef  <Miscellaneous device>
>>>>     bDeviceSubClass = 0x0002
>>>>     bDeviceProtocol = 0x0001
>>>>     bMaxPacketSize0 = 0x0040
>>>>     idVendor = 0x046d
>>>>     idProduct = 0x082d
>>>>     bcdDevice = 0x0011
>>>>     iManufacturer = 0x0000  <no string>
>>>>     iProduct = 0x0002  <HD Pro Webcam C920>
>>>>     iSerialNumber = 0x0001  <1BC69C1F>
>>>>     bNumConfigurations = 0x0001
>>>>
>>>> When uvideo load, show this message
>>>>
>>>> uvideo0 on uhub1
>>>> uvideo0: <vendor 0x046d HD Pro Webcam C920, class 239/2, rev 2.00/0.11, addr 3> on usbus0
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: too many PU descriptors found!
>>>> uvideo0: 3 format(s), iface_index=1, endpoint=0x81, psize=3060, isoc
>>>> uvideo0: default format: pixfmt=0x56595559, 640x480, max_fbuf=4147200
>>>> uvideo0: UVC camera on /dev/video0
>>>>
>>>>
>>> try updating UVIDEO_MAX_PU and UVIDEO_MAX_CT from 8 to 32.
>>>
>>> in sys/dev/usb/video/uvideo.c
>>>
>>> best regards,
>>> Bapt
>> I change these values, PU warnings was gone.
>>
>> My Webcam not work fine yet.
>>
>> See this jpeg screenshot from pwcview using default values to fps and resolution (sif).
>>
>> https://imgur.com/a/YG89hK5
>>
>>
>> ugen0.2: <vendor 0x046d HD Pro Webcam C920> at usbus0
>> uvideo0 on uhub1
>> uvideo0: <vendor 0x046d HD Pro Webcam C920, class 239/2, rev 2.00/0.11, addr 3> on usbus0
>> uvideo0: 3 format(s), iface_index=1, endpoint=0x81, psize=3060, isoc
>> uvideo0: default format: pixfmt=0x56595559, 640x480, max_fbuf=4147200
>> uvideo0: UVC camera on /dev/video0
>> uaudio0 on uhub1
>> uaudio0: <vendor 0x046d HD Pro Webcam C920, class 239/2, rev 2.00/0.11, addr 3> on usbus0
>> uaudio0: No playback.
>> uaudio0: Record[0]: 32000 Hz, 2 ch, 16-bit S-LE PCM format, 2x4ms buffer. (selected)
>> uaudio0: Record[0]: 24000 Hz, 2 ch, 16-bit S-LE PCM format, 2x4ms buffer.
>> uaudio0: Record[0]: 16000 Hz, 2 ch, 16-bit S-LE PCM format, 2x4ms buffer.
>> uaudio0: No MIDI sequencer.
>> pcm6 on uaudio0
>> uaudio0: No HID volume keys found.
>> uvideo0: stream open: nframes=51, psize=3060, maxVideoFrameSize=153600, maxPayloadSize=800, alt=11, isoc
>> uvideo0: stream open: nframes=51, psize=3060, maxVideoFrameSize=153600, maxPayloadSize=800, alt=11, isoc
>>
>>
>>
> on linux it has quirks for this model, I need to implement some. I ll come back with a patch soon
>
> bapt

I'd be happy to help improve this driver by providing more information 
about this camera. Let me know what information would be useful.

Thank you Baptiste.

-- 
**************************
* Dr. Nilton Jose Rizzo  *
* Engenheiro Eletrônico  *
* Doutor pela COPPE/UFRJ *
* Telegram: @njrizzo     *
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