title: using motion on raspberry pi for webcam streaming issue
body: <p>I have a USB webcam (unknown make, no markings) thats been detected fine on my Raspberry Pi.</p>
  
  <p>This is the output of lsusb</p>
  
  <pre><code>Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
  Bus 001 Device 002: ID 0424:9512 Standard Microsystems Corp. 
  Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. 
  Bus 001 Device 004: ID 0c45:608f Microdia PC Camera (SN9C103 + OV7630)
  Bus 001 Device 005: ID 1267:0103 Logic3 / SpectraVideo plc G-720 Keyboard
  </code></pre>
  
  <p>However when i run motion, using /dev/video0 with the only default config changed the resolution and setting the webcam host off so that i can stream it on a network. 
  This is my log when i run motion</p>
  
  <pre><code>Log of motion -n 
  
  [0] Processing thread 0 - config file /etc/motion/motion.conf
  [0] Motion 3.2.12 Started
  [0] ffmpeg LIBAVCODEC_BUILD 3482368 LIBAVFORMAT_BUILD 3478784
  [0] Thread 1 is from /etc/motion/motion.conf
  [0] motion-httpd/3.2.12 running, accepting connections
  [0] motion-httpd: waiting for data on port TCP 8080
  [1] Thread 1 started
  [1] cap.driver: "sonixb"
  [1] cap.card: "USB camera"
  [1] cap.bus_info: "usb-bcm2708_usb-1.2"
  [1] cap.capabilities=0x05000001
  [1] - VIDEO_CAPTURE
  [1] - READWRITE
  [1] - STREAMING
  [1] Config palette index 8 (YU12) doesn't work.
  [1] Supported palettes:
  [1] 0: S910 (S910)
  [1] 1: BA81 (BA81)
  [1] Selected palette BA81
  [1] Test palette BA81 (480x640)
  [1] Adjusting resolution from 480x640 to 160x120.
  [1] Using palette BA81 (160x120) bytesperlines 160 sizeimage 19200 colorspace 00000008
  [1] found control 0x00980900, "Brightness", range 0,255 
  [1]     "Brightness", default 127, current 127
  [1] found control 0x00980911, "Exposure", range 0,1023 
  [1]     "Exposure", default 66, current 66
  [1] found control 0x00980912, "Automatic Gain (and Exposure)", range 0,1 
  [1]     "Automatic Gain (and Exposure)", default 1, current 1
  [1] found control 0x00980913, "Gain", range 0,255 
  [1]     "Gain", default 127, current 127
  [1] mmap information:
  [1] frames=4
  [1] 0 length=20480
  [1] 1 length=20480
  [1] 2 length=20480
  [1] 3 length=20480
  [1] Using V4L2
  [1] Resizing pre_capture buffer to 1 items
  [1] v4l2_next: VIDIOC_DQBUF: EIO (s-&gt;pframe 0): Input/output error
  [1] v4l2_next: VIDIOC_QBUF: Invalid argument
  [1] v4l2_next: VIDIOC_QBUF: Invalid argument
  [1] v4l2_next: VIDIOC_QBUF: Invalid argument
  [1] v4l2_next: VIDIOC_QBUF: Invalid argument
  [1] Error capturing first image
  [1] Started stream webcam server in port 8081
  [1] v4l2_next: VIDIOC_QBUF: Invalid argument
  [1] Video device fatal error - Closing video device
  [1] Closing video device /dev/video0
  [1] Retrying until successful connection with camera
  [1] cap.driver: "sonixb"
  [1] cap.card: "USB camera"
  [1] cap.bus_info: "usb-bcm2708_usb-1.2"
  [1] cap.capabilities=0x05000001
  [1] - VIDEO_CAPTURE
  [1] - READWRITE
  [1] - STREAMING
  [1] Config palette index 8 (YU12) doesn't work.
  [1] Supported palettes:
  [1] 0: S910 (S910)
  [1] 1: BA81 (BA81)
  [1] Selected palette BA81
  [1] Test palette BA81 (480x640)
  [1] Adjusting resolution from 480x640 to 160x120.
  [1] Using palette BA81 (160x120) bytesperlines 160 sizeimage 19200 colorspace 00000008
  [1] found control 0x00980900, "Brightness", range 0,255 
  [1]     "Brightness", default 127, current 127
  [1] found control 0x00980911, "Exposure", range 0,1023 
  [1]     "Exposure", default 66, current 66
  [1] found control 0x00980912, "Automatic Gain (and Exposure)", range 0,1 
  [1]     "Automatic Gain (and Exposure)", default 1, current 1
  [1] found control 0x00980913, "Gain", range 0,255 
  [1]     "Gain", default 127, current 127
  [1] mmap information:
  [1] frames=4
  [1] 0 length=20480
  [1] 1 length=20480
  [1] 2 length=20480
  [1] 3 length=20480
  [1] Using V4L2
  [1] Camera has finally become available
  [1] Camera image has different width and height from what is in the config file. You should fix that
  [1] Restarting Motion thread to reinitialize all image buffers to new picture dimensions
  [1] Thread exiting
  [1] Calling vid_close() from motion_cleanup
  [1] Closing video device /dev/video0
  [0] Motion thread 1 restart
  [1] Thread 1 started
  [1] config image height (120) is not modulo 16
  [1] Could not fetch initial image from camera
  [1] Motion continues using width and height from config file(s)
  [1] Resizing pre_capture buffer to 1 items
  [1] Started stream webcam server in port 8081
  [1] Retrying until successful connection with camera
  [1] config image height (120) is not modulo 16
  [0] httpd - Finishing
  [0] httpd Closing
  [0] httpd thread exit
  [1] Thread exiting
  [0] Motion terminating
  </code></pre>
  
  <p>The light on the camera comes on at the start and then goes off again, does anyone recognise any of the errors i'm getting?</p>
  
  <p>Thanks!</p>