capture.lua

#!/usr/bin/env lua

require "v4l"

function saveimg(img)
 file = io.open("image.ppm", "w+")
 file:write("P3\n".. w .. " " .. h .."\n255\n") -- RGB IMAGE
 for i=1,#img do
    local p = a[i] .. "\n"  
    file:write(p)
  end
  file:close()
end

camera = #arg

if camera < 1 then
  camera = "/dev/video0"
else
  camera = arg[1]
end

dev = v4l.open(camera)

if dev < 0 then
  print("camera not found")
  os.exit(0)
end

w, h = v4l.widht(), v4l.height()

print(camera .. ": " ..w .. "x" .. h)

for i=1,10 do -- take 2 pics to get a better image
   a = v4l.getframe()
-- print(a[i] .. " " .. a[i+1] .. " "..  a[i+2])
end

saveimg(a)
a = nil

dev = v4l.close(dev);

if dev == 0 then
  print("File descriptor closed: " .. dev)
end