more rubustness when user dir is not writable (see #54

imageio/core/util.py

@@ -442,6 +442,7 @@ def appdata_dir(appname=None, roaming=False):
         path = os.path.join(path, appname)
         if not os.path.isdir(path):  # pragma: no cover
             os.mkdir(path)
+
 
     # Done
     return path

imageio/plugins/_freeimage.py

@@ -404,7 +404,11 @@ def _load_freeimage(self):
 
         # todo: we want to load from location relative to exe in frozen apps
         # Get lib dirs
-        lib_dirs = [appdata_dir('imageio')]
+        lib_dirs = []
+        try:
+            lib_dirs.append(appdata_dir('imageio'))
+        except Exception:
+            pass  # The home dir may not be writable
 
         # Make sure that we have our binary version of the libary
         lib_filename = get_freeimage_lib() or 'notavalidlibname'

imageio/plugins/ffmpeg.py

@@ -42,11 +42,18 @@ def get_exe():
     plat = get_platform()
 
     if plat and plat in FNAME_PER_PLATFORM:
-        exe = get_remote_file('ffmpeg/' + FNAME_PER_PLATFORM[plat])
-        os.chmod(exe, os.stat(exe).st_mode | stat.S_IEXEC)  # executable
-        return exe
-    else:
-        return 'ffmpeg'  # Let's hope the system has ffmpeg
+        try:
+            exe = get_remote_file('ffmpeg/' + FNAME_PER_PLATFORM[plat])
+            os.chmod(exe, os.stat(exe).st_mode | stat.S_IEXEC)  # executable
+            return exe
+        except OSError:  # pragma: no cover
+            print("Warning: could not load imageio's ffmpeg library.")
+            e_type, e_value, e_tb = sys.exc_info()
+            del e_tb
+            print(str(e_value))
+
+    # Fallback, let's hope the system has ffmpeg
+    return 'ffmpeg'
 
 
 # Get camera format