--[[
@title Dark Frame Shooter for Meteors
2010/11/16 original script by fudgey 
2012/10/18 modified by waterwingz to shoot continuously and record dark frame periocally
 
@param n Number of Shots
@default n 1000
@param r Raw On/Off (1=On/0=Off)
@default r 1
@param s Shots per Dark Frame
@default s 50
@param t exposure in seconds (0=auto)
@default t 25
--]]
 
propcase=require("propcase")
 
-- Register shutter control event procs depending on os and define functions 
-- openshutter() and closeshutter() to control mechanical shutter.
function init()
 
   set_console_layout(5, 0, 40, 14)
 
  -- check for native call interface:
  if (type(call_event_proc) ~= "function" ) then
    error("your CHDK does not support native calls")
  end    
 
  local bi=get_buildinfo()
 
  if bi.os=="vxworks" then
    closeproc="CloseMShutter"
    openproc="OpenMShutter"
    if (call_event_proc("InitializeAdjustmentFunction") == -1) then
      error("InitAdjFunc failed")
    end
  elseif bi.os=="dryos" then
    closeproc="CloseMechaShutter"
    openproc="OpenMechaShutter"
    if (call_event_proc("Mecha.Create") == -1) then
      error("Mecha.Create failed")
    end     
  else
    error("Unknown OS:" .. bi.os)
  end
 
  -- close mechanical shutter
  function closeshutter()
    if (call_event_proc(closeproc) == -1) then
      print("closeshutter failed")
    end
  end
 
  -- open mechanical shutter
  function openshutter()
    if (call_event_proc(openproc) == -1) then
      print("openshutter failed")
    end
  end
 
  -- switch to record mode if necessary
  if ( get_mode() == false ) then
    print("switching to record mode")
    sleep(1000)
    set_record(1)
    while ( get_mode() == false) do
      sleep(100)
    end
  end
 
  -- test for still photo rec mode:
  rec,vid=get_mode()
  if rec ~= true then
    error("Not in REC mode")
  elseif vid == true then
    error("Video not supported")
  end
 
  -- make sure we are in P mode
  capmode=require("capmode")
  if ( capmode.get_name() ~= "P") then
    error("Not in Program mode!")
  end
 
  -- check that flash is disabled
  if ( get_flash_mode() ~= 2) then
      error("Flash not disabled!")
  end
 
 -- nasty hack to turn seconds into tv96 values
  tv96set=0
  if (t>=10) then tv96set=-320 end
  if (t>=15) then tv96set=-384 end
  if (t>=20) then tv96set=-416 end
  if (t>=25) then tv96set=-448 end
  if (t>=30) then tv96set=-480 end
 
end -- init()
 
-- store current exposure params (to be called during half shoot, after autoexposure has finished)
function get_exposure_params()
  if( t>=10 ) then
      set_prop(propcase.TV,tv96set) -- exposure time
  end
  tv96=get_prop(propcase.TV) -- exposure time
  sv96=get_prop(propcase.SV) -- ISO
  if get_nd_present() ~= 1 then -- aperture if camera has iris
    --av96=get_av96()
    av96=get_prop(propcase.AV)
    print("remembering tv=",tv96,"sv=",sv96,"av=",av96)
  else
    print("remembering tv=",tv96,"sv=",sv96)
  end
end
 
-- set previously saved exposure params (to be called during half shoot, after autoexposure has finished)
function set_exposure_params()
  --set_tv96_direct(tv96) -- exposure time
  --set_sv96(sv96) -- ISO
  set_prop(propcase.TV,tv96) -- exposure time
  set_prop(propcase.SV,sv96) -- ISO
  if get_nd_present() ~= 1 then -- aperture if camera has iris
    --set_av96_direct(av96) 
    set_prop(propcase.AV,av96)
    print("overriding tv=",tv96,"sv=",sv96,"av=",av96)
  else
    print("overriding tv=",tv96,"sv=",sv96)
  end
end
 
--[[ 
     Exposure parameter controlled shoot: if argument dark==false, function stores 
     Tv, Av, Sv from this shot and shoots a real photo. If dark==true, function 
     overrides camera exposure parameters to match previously stored ones and shoots a
     dark frame. Obviously one must always call this function with false before it can be 
     called with true.
--]]
function expcontrol_shoot(dark)
 
-- half shoot and wait for autoexposure (if disabled, it'll finish real fast)
  press("shoot_half")
  repeat
    sleep(1)
  until get_shooting() == true
 
  if dark == true then -- if dark frame    
    set_exposure_params() -- set overrides
    closeshutter() -- close shutter
    sleep(1) -- wait for shutter to close (don't know if this is required)
  end
 
  -- take the photo
  press("shoot_full")
  sleep(1)
 
  if dark ~= true then -- normal photo, store exposure params
    get_exposure_params()
  end
 
  release("shoot_full")
  sleep(1)
  release("shoot_half")
  repeat
    sleep(1)
  until get_shooting() ~= true 
end
 
-- restore user raw mode and dark frame reduction settings:
function restore()
   set_raw(rawmode)
   set_raw_nr(dfrmode)
end
 
 
-- store user raw mode and dark frame reduction settings
rawmode=get_raw()
dfrmode=get_raw_nr()
 
-- script starts here
init()
 
set_raw(r) -- enable RAW or DNG
set_raw_nr(1) -- disable Canon's dark frame reduction
 
j=s
for i=1,n do
    print("shooting RAW+JPG", i, "of",n)
    expcontrol_shoot(false) -- shoot a photo, store its exposure params
    if j >= s then
        j=0
        print("shooting a dark frame")
        expcontrol_shoot(true) -- shoot dark frame using stored exposure parameters
    else
        j=j+1
   end
end
 
print("shooting final dark frame")
expcontrol_shoot(true) 
 
restore()
print("done")