Add 'tmpdir' option to convert plugin

Closes #1382

Add tmpdir setting

document tmpdir setting

beetsplug/convert.py

@@ -125,6 +125,7 @@ def __init__(self):
             },
             u'max_bitrate': 500,
             u'auto': False,
+            u'tmpdir': None,
             u'quiet': False,
             u'embed': True,
             u'paths': {},
@@ -388,7 +389,8 @@ def convert_on_import(self, lib, item):
         fmt = self.config['format'].get(unicode).lower()
         if should_transcode(item, fmt):
             command, ext = get_format()
-            fd, dest = tempfile.mkstemp('.' + ext)
+            tmpdir = self.config['tmpdir'].get()
+            fd, dest = tempfile.mkstemp('.' + ext, dir=tmpdir)
             os.close(fd)
             _temp_files.append(dest)  # Delete the transcode later.
             try:

docs/plugins/convert.rst

@@ -58,6 +58,8 @@ file. The available options are:
   default configuration) non-MP3 files over the maximum bitrate before adding
   them to your library.
   Default: ``no``.
+- **tmpdir**: The directory where temporary files will be stored during import.
+  Default: none (system default),
 - **copy_album_art**: Copy album art when copying or transcoding albums matched
   using the ``-a`` option. Default: ``no``.
 - **dest**: The directory where the files will be converted (or copied) to.