#!/usr/bin/env python

from __future__ import print_function

import os, sys

import subprocess

import datetime

# There is something like a set of gphoto2 python bindings, at

# http://magiclantern.wikia.com/wiki/Remote_control_with_PTP_and_Python

# but it's not widely available and you'd have to compile it for the RPi.

camera_name = None

def has_camera():

'''Is there a gphoto2-compatible camera installed?

gphoto2 --auto-detect doesn't do anything helpful like,

say, exiting with a different status if there's no camera.

So we have to parse the output.

'''

try:

output = subprocess.check_output(["/usr/bin/gphoto2",

"--auto-detect"]).split('\n')

seen_separator = False

for line in output:

if seen_separator:

if len(line) > 1 and not line[0].isspace():

global camera_name

camera_name = line.strip()

return camera_name

elif line.startswith("---------------"):

seen_separator = True

return False

except:

return False

class Gphoto :

def __init__(self, res=None, verbose=False):

'''May raise CalledProcessError or NotImplementedError

if there's no compatible camera connected and switched on.

XXX res is ignored for now.

'''

self.verbose = verbose

def check_config(self):

'''This routine tends to fail -- gphoto2 prints

"** Error (-1: 'Unspecified error') ***" --

even when the camera can capture just fine. So skip it.

'''

# Do we have a real camera attached using PTP so gphoto2 can talk to it?

has_capture = False

# For some reason gphoto2 --list-config ALWAYS exits with nonzero

# and "*** Error (-1: 'Unspecified error') ***"

# so alas we have to ignore error returns.

# gphoto2 --set-config capture=1 --list-config is the right way.

try:

args = [ "/usr/bin/gphoto2",

# "--debug", "--debug-logfile=/tmp/log.txt",

"--list-config",

"capture=on"]

config = subprocess.check_output(args)

except subprocess.CalledProcessError as e:

print("list-config exited with status", e.returncode)

config = e.output

print("output was: <START>", end=' ')

print(config)

print("<END>")

for line in config.split('\n'):

if line.startswith('/main/settings/capture'):

has_capture = True

break

else: print(line, "isn't capture")

if not has_capture:

raise NotImplementedError

def take_still(self, outfile=None, res=None, zoom=None):

if res:

print("Warning: gphoto wrapper ignoring resolution", res)

# gphoto2 can only take photos to files on the same filesystem

# as the current working directory.

print()

# So if outfile points to another filesystem, we need to

# change directory to that filesystem.

if outfile and outfile != '-':

if outfile[0] == '/':

outdir = os.path.split(outfile)[0]

if os.stat(outdir).st_dev != os.stat(os.getcwd()).st_dev:

if self.verbose:

print(outfile, "is not on the same filesystem as", \

os.getcwd())

print("Changing directory to", outdir)

os.chdir(outdir)

# XXX should we change back afterward?

# gphoto2 will also prompt if the target file already exists,

# so we have to rename or remove it.

print("Checking whether", outfile, "exists already")

if os.path.exists(outfile):

if self.verbose:

print("Renaming", outfile, "to", outfile + ".bak")

os.rename(outfile, outfile + ".bak")

else:

print("Not checking, outfile =", outfile)

if not outfile:

now = datetime.datetime.now()

outfile = "snap-%04d-%02d-%02d-%02d-%02d-%02d.jpg" % \

(now.year, now.month, now.day, now.hour, now.minute, now.second)

# gphoto2 can handle date formatting, but in that case

# we'd have no idea what the actual filename was

# so we couldn't do anything with it later.

print("outfile is now", outfile)

args = [ "/usr/bin/gphoto2", "--set-config", "syncdatetime=1",

"--set-config", "capturetarget=sdram" ]

if zoom:

args.append("--set-config")

args.append("zoom=%s" % str(zoom))

# The capture image command and filename have to come last:

args.append("--capture-image-and-download")

args.append("--filename")

args.append(outfile)

if self.verbose:

print("Calling:", args)

rv = subprocess.call(args)

if __name__ == '__main__':

gphoto = Gphoto(verbose=True)

if not gphoto.has_camera():

print("No camera connected!")

sys.exit(0)

gphoto.take_still()

gphoto.take_still(zoom=10)