[Distro bug]: camera dark after biopass uses it

[fivenote]

Summary

After biopass uses the camera, the image is dark when used by other apps. I have to run guvcview to reset to default.

System

• Distro and version: LMDE 7
• Kernel version: Linux mx11 6.12.96+deb13-amd64 Feat/cli #1 SMP PREEMPT_DYNAMIC Debian 6.12.96-1 (2026-07-20) x86_64 GNU/Linux
• Desktop environment: cinnamon
• Display manager: Muffin (X11)
• Package source (.deb, .rpm, AUR, source build, other): .deb file
• Biopass version: 1.4.1

Authentication path

• Feature affected: face
• PAM file or distro auth tool involved: common-auth
• Command or login flow that fails:

Steps to reproduce

1. ffplay /dev/video0 - normal camera image
2. run biopass settings to activate camera, or via unlock
3. ffplay /dev/video0 - image is dark

Expected behavior

What should happen? Biopass should reset default camera setting when done

Actual behavior

What happened instead? Biopass sets to dark image, fails to authenticate in moderate low light, leaves camera in this state. Seems to be related to changing Pixel Format and FPS (see below)

Logs and evidence

Camera Before...

$ v4l2-ctl -d /dev/video0 --get-fmt-video --get-parm
Format Video Capture:
Width/Height : 640/480
Pixel Format : 'MJPG' (Motion-JPEG)
Field : None
Bytes per Line : 0
Size Image : 614989
Colorspace : sRGB
Transfer Function : Default (maps to sRGB)
YCbCr/HSV Encoding: Default (maps to ITU-R 601)
Quantization : Default (maps to Full Range)
Flags :
Streaming Parameters Video Capture:
Capabilities : timeperframe
Frames per second: 30.000 (30/1)
Read buffers : 0

Camera After:

$ v4l2-ctl -d /dev/video0 --get-fmt-video --get-parm
Format Video Capture:
Width/Height : 1280/720
Pixel Format : 'YUYV' (YUYV 4:2:2)
Field : None
Bytes per Line : 2560
Size Image : 1843200
Colorspace : sRGB
Transfer Function : Rec. 709
YCbCr/HSV Encoding: ITU-R 601
Quantization : Default (maps to Limited Range)
Flags :
Streaming Parameters Video Capture:
Capabilities : timeperframe
Frames per second: 10.000 (10/1)
Read buffers : 0

Additional context

Dell XPS 9310
Bus 003 Device 003: ID 0c45:672a Microdia Integrated_Webcam_HD