Logitech HD Pro Webcam C920 USB webcam resolution

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

Hello,

I have a USB Logitech HD Pro Webcam C920 connected to a raspberrypi4 in 
NetBSD 10.1.


netbsd-raspa4$ dmesg
..
..


[     3,158337] video0 at uvideo0: vendor 046d (0x046d) HD Pro Webcam 
C920 (0x0892), rev 2.00/0.19, addr 2
[     3,168337] uaudio0 at uhub2 port 1 configuration 1 interface 2
[     3,168337] uaudio0: vendor 046d (0x046d) HD Pro Webcam C920 
(0x0892), rev 2.00/0.19, addr 2
[     3,178337] uaudio0: audio rev 1.00
[     3,188337] audio0 at uaudio0: capture
[     3,188337] audio0: slinear_le:16 2ch 32000Hz, blk 7920 bytes 
(61.8ms) for recording
[     3,198337] swwdog0: software watchdog initialized
[     3,208339] boot device: dk1
[     3,208339] root on dk1
[     3,218338] root file system type: ffs
[     3,228338] kern.module.path=/stand/evbarm/10.1/modules
..
..

I am having trouble to get proper pictures and videos from it.

with:

$ffmpeg7 -f v4l2 -i /dev/video0 -vframes 1 output.jpg

I get a very dark picture.

with:

ffmpeg7 -f v4l2 -i /dev/video0 -vframes 5  output_%02d.jpg

I get one or two dark exposures and then good exposed remaning  ones.

But I get only 640x480 pixels pictures.

netbsd-raspa4$ file output*
output_01.jpg: JPEG image data, baseline, precision 8, 640x480, components 3
output_02.jpg: JPEG image data, baseline, precision 8, 640x480, components 3
output_03.jpg: JPEG image data, baseline, precision 8, 640x480, components 3
output_04.jpg: JPEG image data, baseline, precision 8, 640x480, components 3
output_05.jpg: JPEG image data, baseline, precision 8, 640x480, components 3

with:
ffmpeg7 -f video4linux2 -i /dev/video0  output.mp4

I get a 640x480 pixels video.

with:
ffmpeg7 -f v4l2 -i /dev/video0 -vframes 5 -s 1920x1080  output_%02d.jpg

I get fake 1920x1080 pictures without any increase in actual resolution.

netbsd-raspa4$ file out*
output.mp4:    ISO Media, MP4 Base Media v1 [ISO 14496-12:2003]
output_01.jpg: JPEG image data, baseline, precision 8, 1920x1080, 
components 3
output_02.jpg: JPEG image data, baseline, precision 8, 1920x1080, 
components 3
output_03.jpg: JPEG image data, baseline, precision 8, 1920x1080, 
components 3
output_04.jpg: JPEG image data, baseline, precision 8, 1920x1080, 
components 3
output_05.jpg: JPEG image data, baseline, precision 8, 1920x1080, 
components 3

Also would like to control focus and exposure to get some kind of manual 
control.

I know that in Linux there is a v4l2-ctl utility to fine tune the 
camera, but it seems not to be available in NetBSD. Is there a way to 
overcome that?

Thanks so much in advance.

Ramiro.

















ffmpeg7 -f v4l2 -i /dev/video0 -vframes 4  output_%02d.jpg    así sale 
bien a partir de la terc