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 mediagoblin import mg_globals as mgg
  21
  22 from mediagoblin.processing import BadMediaFail, \
  23     create_pub_filepath, THUMB_SIZE, MEDIUM_SIZE
  24
  25 ################################
  26 # Media processing initial steps
  27 ################################
  28
  29
  30 def process_image(entry):
  31     """
  32     Code to process an image
  33     """
  34     workbench = mgg.workbench_manager.create_workbench()
  35     # Conversions subdirectory to avoid collisions
  36     conversions_subdir = os.path.join(
  37         workbench.dir, 'conversions')
  38     os.mkdir(conversions_subdir)
  39
  40     queued_filepath = entry.queued_media_file
  41     queued_filename = workbench.localized_file(
  42         mgg.queue_store, queued_filepath,
  43         'source')
  44
  45     filename_bits = os.path.splitext(queued_filename)
  46     basename = os.path.split(filename_bits[0])[1]
  47     extension = filename_bits[1].lower()
  48
  49     try:
  50         thumb = Image.open(queued_filename)
  51     except IOError:
  52         raise BadMediaFail()
  53
  54     thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
  55
  56     # Copy the thumb to the conversion subdir, then remotely.
  57     thumb_filename = 'thumbnail' + extension
  58     thumb_filepath = create_pub_filepath(entry, thumb_filename)
  59     tmp_thumb_filename = os.path.join(
  60         conversions_subdir, thumb_filename)
  61     with file(tmp_thumb_filename, 'w') as thumb_file:
  62         thumb.save(thumb_file)
  63     mgg.public_store.copy_local_to_storage(
  64         tmp_thumb_filename, thumb_filepath)
  65
  66     # If the size of the original file exceeds the specified size of a `medium`
  67     # file, a `medium.jpg` files is created and later associated with the media
  68     # entry.
  69     medium = Image.open(queued_filename)
  70     medium_processed = False
  71
  72     if medium.size[0] > MEDIUM_SIZE[0] or medium.size[1] > MEDIUM_SIZE[1]:
  73         medium.thumbnail(MEDIUM_SIZE, Image.ANTIALIAS)
  74
  75         medium_filename = 'medium' + extension
  76         medium_filepath = create_pub_filepath(entry, medium_filename)
  77         tmp_medium_filename = os.path.join(
  78             conversions_subdir, medium_filename)
  79
  80         with file(tmp_medium_filename, 'w') as medium_file:
  81             medium.save(medium_file)
  82
  83         mgg.public_store.copy_local_to_storage(
  84             tmp_medium_filename, medium_filepath)
  85
  86         medium_processed = True
  87
  88     # we have to re-read because unlike PIL, not everything reads
  89     # things in string representation :)
  90     queued_file = file(queued_filename, 'rb')
  91
  92     with queued_file:
  93         #create_pub_filepath(entry, queued_filepath[-1])
  94         original_filepath = create_pub_filepath(entry, basename + extension)
  95
  96         with mgg.public_store.get_file(original_filepath, 'wb') \
  97             as original_file:
  98             original_file.write(queued_file.read())
  99
 100     mgg.queue_store.delete_file(queued_filepath)
 101     entry.queued_media_file = []
 102     media_files_dict = entry.setdefault('media_files', {})
 103     media_files_dict['thumb'] = thumb_filepath
 104     media_files_dict['original'] = original_filepath
 105     if medium_processed:
 106         media_files_dict['medium'] = medium_filepath
 107
 108     # clean up workbench
 109     workbench.destroy_self()