Gnome Cheese Overwrites gsettings

[Allan W. Macdonald]

I cannot get cheese to use my external USB webcam.

cheese: 3.28.0-1ubuntu1
OS: 18.04.3 LTS on x86_64
gnome: 3.28.2

After plugging in the webcam, a new device appears at /dev/video2.

Before running cheese, I set the camera setting as follows:

$ gsettings set org.gnome.Cheese camera '/dev/video2'

I then confirm the settings are correct:

$ gsettings list-recursively org.gnome.Cheese
org.gnome.Cheese countdown-duration 3
org.gnome.Cheese flash true
org.gnome.Cheese photo-y-resolution 480
org.gnome.Cheese countdown true
org.gnome.Cheese brightness 0.0
org.gnome.Cheese saturation 1.0
org.gnome.Cheese video-y-resolution 480
org.gnome.Cheese camera '/dev/video2'
org.gnome.Cheese burst-repeat 4
org.gnome.Cheese photo-x-resolution 640
org.gnome.Cheese contrast 1.0
org.gnome.Cheese photo-path ''
org.gnome.Cheese selected-effect 'identity'
org.gnome.Cheese video-x-resolution 640
org.gnome.Cheese burst-delay 1000
org.gnome.Cheese hue 0.0
org.gnome.Cheese video-path ''

I then run the Cheese app, open the Preferences menu and find that the Device field is greyed out and shows just one choice: "BisonCam, NB Pro: BisonCam, NB"

I then run gsettings again:
$ gsettings list-recursively org.gnome.Cheese
org.gnome.Cheese countdown-duration 3
org.gnome.Cheese flash true
org.gnome.Cheese photo-y-resolution 480
org.gnome.Cheese countdown true
org.gnome.Cheese brightness 0.0
org.gnome.Cheese saturation 1.0
org.gnome.Cheese video-y-resolution 480
org.gnome.Cheese camera 'BisonCam, NB Pro: BisonCam, NB'
org.gnome.Cheese burst-repeat 4
org.gnome.Cheese photo-x-resolution 640
org.gnome.Cheese contrast 1.0
org.gnome.Cheese photo-path ''
org.gnome.Cheese selected-effect 'identity'
org.gnome.Cheese video-x-resolution 640
org.gnome.Cheese burst-delay 1000
org.gnome.Cheese hue 0.0
org.gnome.Cheese video-path ''

So, cheese seems to overwrite the gconf settings. I can't figure out how to get cheese to use my USB webcam!

Additional info:

$ sudo lsusb -v -s 003:036

Bus 003 Device 036: ID 0ac8:0302 Z-Star Microelectronics Corp. ZC0302 Webcam
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 1.10
  bDeviceClass 0 (Defined at Interface level)
  bDeviceSubClass 0
  bDeviceProtocol 0
  bMaxPacketSize0 8
  idVendor 0x0ac8 Z-Star Microelectronics Corp.
  idProduct 0x0302 ZC0302 Webcam
  bcdDevice 1.00
  iManufacturer 1 V Micro. Corp.
  iProduct 2 PC Camera
  iSerial 0
  bNumConfigurations 1
  Configuration Descriptor:
    bLength 9
    bDescriptorType 2
    wTotalLength 336
    bNumInterfaces 3
    bConfigurationValue 1
    iConfiguration 0
    bmAttributes 0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower 160mA
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 0
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0000 1x 0 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 1
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0080 1x 128 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 2
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x00c0 1x 192 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 3
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0100 1x 256 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 4
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0180 1x 384 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 5
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0200 1x 512 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 6
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0300 1x 768 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 7
      bNumEndpoints 2
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 255 Vendor Specific Protocol
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x03ff 1x 1023 bytes
        bInterval 1
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x82 EP 2 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0008 1x 8 bytes
        bInterval 10
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 1
      bAlternateSetting 0
      bNumEndpoints 0
      bInterfaceClass 1 Audio
      bInterfaceSubClass 1 Control Device
      bInterfaceProtocol 0
      iInterface 0
      AudioControl Interface Descriptor:
        bLength 9
        bDescriptorType 36
        bDescriptorSubtype 1 (HEADER)
        bcdADC 1.00
        wTotalLength 39
        bInCollection 1
        baInterfaceNr( 0) 2
      AudioControl Interface Descriptor:
        bLength 12
        bDescriptorType 36
        bDescriptorSubtype 2 (INPUT_TERMINAL)
        bTerminalID 1
        wTerminalType 0x0201 Microphone
        bAssocTerminal 0
        bNrChannels 1
        wChannelConfig 0x0000
        iChannelNames 0
        iTerminal 0
      AudioControl Interface Descriptor:
        bLength 9
        bDescriptorType 36
        bDescriptorSubtype 6 (FEATURE_UNIT)
        bUnitID 2
        bSourceID 1
        bControlSize 2
        bmaControls( 0) 0x43
        bmaControls( 0) 0x00
          Mute Control
          Volume Control
          Automatic Gain Control
        iFeature 0
      AudioControl Interface Descriptor:
        bLength 9
        bDescriptorType 36
        bDescriptorSubtype 3 (OUTPUT_TERMINAL)
        bTerminalID 3
        wTerminalType 0x0101 USB Streaming
        bAssocTerminal 0
        bSourceID 2
        iTerminal 0
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 2
      bAlternateSetting 0
      bNumEndpoints 0
      bInterfaceClass 1 Audio
      bInterfaceSubClass 2 Streaming
      bInterfaceProtocol 0
      iInterface 0
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 2
      bAlternateSetting 1
      bNumEndpoints 1
      bInterfaceClass 1 Audio
      bInterfaceSubClass 2 Streaming
      bInterfaceProtocol 0
      iInterface 0
      AudioStreaming Interface Descriptor:
        bLength 7
        bDescriptorType 36
        bDescriptorSubtype 1 (AS_GENERAL)
        bTerminalLink 3
        bDelay 1 frames
        wFormatTag 1 PCM
      AudioStreaming Interface Descriptor:
        bLength 11
        bDescriptorType 36
        bDescriptorSubtype 2 (FORMAT_TYPE)
        bFormatType 1 (FORMAT_TYPE_I)
        bNrChannels 1
        bSubframeSize 2
        bBitResolution 16
        bSamFreqType 1 Discrete
        tSamFreq[ 0] 8000
      Endpoint Descriptor:
        bLength 9
        bDescriptorType 5
        bEndpointAddress 0x83 EP 3 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0010 1x 16 bytes
        bInterval 1
        bRefresh 0
        bSynchAddress 0
        AudioControl Endpoint Descriptor:
          bLength 7
          bDescriptorType 37
          bDescriptorSubtype 1 (EP_GENERAL)
          bmAttributes 0x00
          bLockDelayUnits 0 Undefined
          wLockDelay 0 Undefined
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 2
      bAlternateSetting 2
      bNumEndpoints 1
      bInterfaceClass 1 Audio
      bInterfaceSubClass 2 Streaming
      bInterfaceProtocol 0
      iInterface 0
      AudioStreaming Interface Descriptor:
        bLength 7
        bDescriptorType 36
        bDescriptorSubtype 1 (AS_GENERAL)
        bTerminalLink 3
        bDelay 1 frames
        wFormatTag 1 PCM
      AudioStreaming Interface Descriptor:
        bLength 11
        bDescriptorType 36
        bDescriptorSubtype 2 (FORMAT_TYPE)
        bFormatType 1 (FORMAT_TYPE_I)
        bNrChannels 1
        bSubframeSize 2
        bBitResolution 16
        bSamFreqType 1 Discrete
        tSamFreq[ 0] 16000
      Endpoint Descriptor:
        bLength 9
        bDescriptorType 5
        bEndpointAddress 0x83 EP 3 IN
        bmAttributes 1
          Transfer Type Isochronous
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0020 1x 32 bytes
        bInterval 1
        bRefresh 0
        bSynchAddress 0
        AudioControl Endpoint Descriptor:
          bLength 7
          bDescriptorType 37
          bDescriptorSubtype 1 (EP_GENERAL)
          bmAttributes 0x00
          bLockDelayUnits 0 Undefined
          wLockDelay 0 Undefined
Device Status: 0x0000
  (Bus Powered)

$ v4l2-ctl --list-devices
PC Camera (usb-0000:00:14.0-2):
 /dev/video2

BisonCam, NB Pro: BisonCam, NB (usb-0000:00:14.0-8):
 /dev/video0
 /dev/video1

Note: There are a few other cheese-related bugs out there that are more vaguely-reported, such as "doesn't work with my webcam", etc. I am not sure if this bug is a duplicate of those bugs or perhaps this bug is the root of some ot those other bugs!