mediagoblin/media_types/image/processing.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 import Image
  18 import os
  19
  20 from celery.task import Task
  21 from celery import registry
  22
  23 from mediagoblin.db.util import ObjectId
  24 from mediagoblin import mg_globals as mgg
  25
  26 from mediagoblin.processing import BaseProcessingFail, \
  27     mark_entry_failed, BadMediaFail, create_pub_filepath, THUMB_SIZE, \
  28     MEDIUM_SIZE
  29
  30 ################################
  31 # Media processing initial steps
  32 ################################
  33
  34
  35 def process_image(entry):
  36     """
  37     Code to process an image
  38     """
  39     workbench = mgg.workbench_manager.create_workbench()
  40     # Conversions subdirectory to avoid collisions
  41     conversions_subdir = os.path.join(
  42         workbench.dir, 'conversions')
  43     os.mkdir(conversions_subdir)
  44
  45     queued_filepath = entry['queued_media_file']
  46     queued_filename = workbench.localized_file(
  47         mgg.queue_store, queued_filepath,
  48         'source')
  49
  50     filename_bits = os.path.splitext(queued_filename)
  51     basename = os.path.split(filename_bits[0])[1]
  52     extension = filename_bits[1].lower()
  53
  54     try:
  55         thumb = Image.open(queued_filename)
  56     except IOError:
  57         raise BadMediaFail()
  58
  59     thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
  60
  61     # Copy the thumb to the conversion subdir, then remotely.
  62     thumb_filename = 'thumbnail' + extension
  63     thumb_filepath = create_pub_filepath(entry, thumb_filename)
  64     tmp_thumb_filename = os.path.join(
  65         conversions_subdir, thumb_filename)
  66     with file(tmp_thumb_filename, 'w') as thumb_file:
  67         thumb.save(thumb_file)
  68     mgg.public_store.copy_local_to_storage(
  69         tmp_thumb_filename, thumb_filepath)
  70
  71     # If the size of the original file exceeds the specified size of a `medium`
  72     # file, a `medium.jpg` files is created and later associated with the media
  73     # entry.
  74     medium = Image.open(queued_filename)
  75     medium_processed = False
  76
  77     if medium.size[0] > MEDIUM_SIZE[0] or medium.size[1] > MEDIUM_SIZE[1]:
  78         medium.thumbnail(MEDIUM_SIZE, Image.ANTIALIAS)
  79
  80         medium_filename = 'medium' + extension
  81         medium_filepath = create_pub_filepath(entry, medium_filename)
  82         tmp_medium_filename = os.path.join(
  83             conversions_subdir, medium_filename)
  84
  85         with file(tmp_medium_filename, 'w') as medium_file:
  86             medium.save(medium_file)
  87
  88         mgg.public_store.copy_local_to_storage(
  89             tmp_medium_filename, medium_filepath)
  90
  91         medium_processed = True
  92
  93     # we have to re-read because unlike PIL, not everything reads
  94     # things in string representation :)
  95     queued_file = file(queued_filename, 'rb')
  96
  97     with queued_file:
  98         #create_pub_filepath(entry, queued_filepath[-1])
  99         original_filepath = create_pub_filepath(entry, basename + extension)
 100
 101         with mgg.public_store.get_file(original_filepath, 'wb') \
 102             as original_file:
 103             original_file.write(queued_file.read())
 104
 105     mgg.queue_store.delete_file(queued_filepath)
 106     entry['queued_media_file'] = []
 107     media_files_dict = entry.setdefault('media_files', {})
 108     media_files_dict['thumb'] = thumb_filepath
 109     media_files_dict['original'] = original_filepath
 110     if medium_processed:
 111         media_files_dict['medium'] = medium_filepath
 112
 113     # clean up workbench
 114     workbench.destroy_self()