camera.docstring

Initializes the dv4l camera interface

SYNOPSIS

    import dv4l

    camera = dv4l.camera("/dev/video0")

    timestamp,image = camera.get_frame()

The dv4l.camera object is used to connect to a video4linux2 camera, and to read
images from it.

ARGUMENTS

- device: required string. The device node we are talking to. Often looks like
  "/dev/video0"

- width
  height

  optional integers requesting a particular image size. These are suggestions,
  and the driver may or may not accept these. If omitted, or <0, we'll ask the
  driver for the biggest images possible.

- fps: optional integer requesting a particular frame rate. This is a suggestion
  as well. If omitted or <0, we'll get the fastest framerate possible

- streaming: optional boolean, defaulting to True. If true: the driver fills in
  internal memory buffers with frames as soon as the data is available, and we
  can read off that data later, whenever we like. We mmap() these buffers at
  init time. If false we read() the data from the port. I'm not clear on the
  exact semantic differences yet

- pixelformat_input: an optional fourcc string of 4 characters (or fewer)
  requesting an input pixel format. As with the other arguments, this is a
  suggestion only. A console message will be printed if our explicit request was
  rejected. If omitted, we take the first available pixel format. The v4l-info
  tool can be used to get a list of available formats

- pixelformat_output: an optional fourcc string of 4 characters (or fewer)
  requesting an output pixel format. Currently only these formats are supported:

  - "GREY": 8-bit grayscale
  - "Y16":  16-bit grayscale
  - "RGB24": 8-bit-per-pixel 3-channel (red,green,blue) color
  - "BGR24": 8-bit-per-pixel 3-channel (blue,green,red) color

  Any other output format is an error. If omitted, we default to "BGR24".

RETURNED VALUE

The dv4l.camera object we can then use to get frames