diff --git a/beets/importer.py b/beets/importer.py
index 558dcc03c..060a188c9 100644
--- a/beets/importer.py
+++ b/beets/importer.py
@@ -179,6 +179,7 @@ class ImportSession(object):
         self.paths = paths
         self.query = query
         self.seen_idents = set()
+        self._is_resuming = dict()
 
         # Normalize the paths.
         if self.paths:
@@ -294,6 +295,50 @@ class ImportSession(object):
             # User aborted operation. Silently stop.
             pass
 
+    # Incremental and resumed imports
+
+    def already_imported(self, toppath, paths):
+        """Returns true if the files belonging to this task have already
+        been imported in a previous session.
+        """
+        if self.is_resuming(toppath) \
+           and all(map(lambda p: progress_element(toppath, p), paths)):
+            return True
+        if self.config['incremental'] \
+           and tuple(paths) in self.history_dirs:
+            return True
+
+        return False
+
+    @property
+    def history_dirs(self):
+        if not hasattr(self, '_history_dirs'):
+            self._history_dirs = history_get()
+        return self._history_dirs
+
+    def is_resuming(self, toppath):
+        """Return `True` if user wants to resume import of this path.
+
+        You have to call `ask_resume` first to determine the return value.
+        """
+        return self._is_resuming.get(toppath, False)
+
+    def ask_resume(self, toppath):
+        """If import of `toppath` was aborted in an earlier session, ask
+        user if she wants to resume the import.
+
+        Determines the return value of `is_resuming(toppath)`.
+        """
+        if self.want_resume and has_progress(toppath):
+            # Either accept immediately or prompt for input to decide.
+            if self.want_resume is True or \
+               self.should_resume(toppath):
+                log.warn('Resuming interrupted import of %s' % toppath)
+                self._is_resuming[toppath] = True
+            else:
+                # Clear progress; we're starting from the top.
+                progress_reset(toppath)
+
 
 # The importer task class.
 
@@ -638,10 +683,6 @@ class SingletonImportTask(ImportTask):
     def imported_items(self):
         return [self.item]
 
-    def save_history(self):
-        # TODO we should also save history for singletons
-        pass
-
     def apply_metadata(self):
         autotag.apply_item_metadata(self.item, self.match.info)
 
@@ -819,24 +860,11 @@ def read_tasks(session):
     in the user-specified list of paths. In the case of a singleton
     import, yields single-item tasks instead.
     """
-    # Look for saved incremental directories.
-    if session.config['incremental']:
-        incremental_skipped = 0
-        history_dirs = history_get()
-
+    skipped = 0
     for toppath in session.paths:
 
         # Determine if we want to resume import of the toppath
-        resuming = False
-        if session.want_resume and has_progress(toppath):
-            # Either accept immediately or prompt for input to decide.
-            if session.want_resume is True or \
-               session.should_resume(toppath):
-                log.warn('Resuming interrupted import of %s' % toppath)
-                resuming = True
-            else:
-                # Clear progress; we're starting from the top.
-                progress_reset(toppath)
+        session.ask_resume(toppath)
 
         # Extract archives.
         archive_task = None
@@ -860,7 +888,13 @@ def read_tasks(session):
 
         # Check whether the path is to a file.
         if not os.path.isdir(syspath(toppath)):
-            if resuming and progress_element(toppath, toppath):
+            # FIXME remove duplicate code. We could put the debug
+            # statement into `session.alread_imported` but I don't feel
+            # comfortable triggering an action in a query.
+            if session.already_imported(toppath, toppath):
+                log.debug(u'Skipping previously-imported path: {0}'
+                          .format(displayable_path(toppath)))
+                skipped += 1
                 continue
 
             try:
@@ -882,32 +916,33 @@ def read_tasks(session):
             for _, items in autotag.albums_in_dir(toppath):
                 all_items += items
             if all_items:
+                if session.already_imported(toppath, [toppath]):
+                    log.debug(u'Skipping previously-imported path: {0}'
+                              .format(displayable_path(toppath)))
+                    skipped += 1
+                    continue
                 yield ImportTask(toppath, [toppath], all_items)
                 yield SentinelImportTask(toppath)
             continue
 
         # Produce paths under this directory.
         for paths, items in autotag.albums_in_dir(toppath):
-            # Skip according to progress.
-            if resuming \
-               and all(map(lambda p: progress_element(toppath, p), paths)):
-                continue
-
-            # When incremental, skip paths in the history.
-            if session.config['incremental'] \
-               and tuple(paths) in history_dirs:
-                log.debug(u'Skipping previously-imported path: %s' %
-                          displayable_path(paths))
-                incremental_skipped += 1
-                continue
-
-            # Yield all the necessary tasks.
             if session.config['singletons']:
                 for item in items:
-                    if not (resuming and progress_element(toppath, item.path)):
-                        yield SingletonImportTask(toppath, item)
+                    if session.already_imported(toppath, [item.path]):
+                        log.debug(u'Skipping previously-imported path: {0}'
+                                  .format(displayable_path(paths)))
+                        skipped += 1
+                        continue
+                    yield SingletonImportTask(toppath, item)
                 yield SentinelImportTask(toppath, paths)
+
             else:
+                if session.already_imported(toppath, paths):
+                    log.debug(u'Skipping previously-imported path: {0}'
+                              .format(displayable_path(paths)))
+                    skipped += 1
+                    continue
                 yield ImportTask(toppath, paths, items)
 
         # Indicate the directory is finished.
@@ -918,9 +953,8 @@ def read_tasks(session):
             yield archive_task
 
     # Show skipped directories.
-    if session.config['incremental'] and incremental_skipped:
-        log.info(u'Incremental import: skipped %i directories.' %
-                 incremental_skipped)
+    if skipped:
+        log.info(u'Skipped {0} directories.'.format(skipped))
 
 
 def query_tasks(session):
diff --git a/beetsplug/convert.py b/beetsplug/convert.py
index 8bf048039..a94f4c284 100644
--- a/beetsplug/convert.py
+++ b/beetsplug/convert.py
@@ -25,6 +25,7 @@ import pipes
 from beets import ui, util, plugins, config
 from beets.plugins import BeetsPlugin
 from beetsplug.embedart import embed_item
+from beets.util.confit import ConfigTypeError
 
 log = logging.getLogger('beets')
 _fs_lock = threading.Lock()
@@ -37,57 +38,53 @@ ALIASES = {
 }
 
 
-def _destination(dest_dir, item, keep_new, path_formats):
-    """Return the path under `dest_dir` where the file should be placed
-    (possibly after conversion).
+def replace_ext(path, ext):
+    """Return the path with its extension replaced by `ext`.
+
+    The new extension must not contain a leading dot.
     """
-    dest = item.destination(basedir=dest_dir, path_formats=path_formats)
-    if keep_new:
-        # When we're keeping the converted file, no extension munging
-        # occurs.
-        return dest
-    else:
-        # Otherwise, replace the extension.
-        _, ext = get_format()
-        return os.path.splitext(dest)[0] + ext
+    return os.path.splitext(path)[0] + '.' + ext
 
 
-def get_format():
-    """Get the currently configured format command and extension.
+def get_format(format=None):
+    """Return the command tempate and the extension from the config.
     """
-    format = config['convert']['format'].get(unicode).lower()
+    if not format:
+        format = config['convert']['format'].get(unicode).lower()
     format = ALIASES.get(format, format)
-    format_info = config['convert']['formats'][format].get(dict)
-
-    # Convenience and backwards-compatibility shortcuts.
-    keys = config['convert'].keys()
-    if 'command' in keys:
-        format_info['command'] = config['convert']['command'].get(unicode)
-    elif 'opts' in keys:
-        # Undocumented option for backwards compatibility with < 1.3.1.
-        format_info['command'] = u'ffmpeg -i $source -y {0} $dest'.format(
-            config['convert']['opts'].get(unicode)
-        )
-    if 'extension' in keys:
-        format_info['extension'] = config['convert']['extension'].get(unicode)
 
     try:
-        return (
-            format_info['command'].encode('utf8'),
-            (u'.' + format_info['extension']).encode('utf8'),
-        )
+        format_info = config['convert']['formats'][format].get(dict)
+        command = format_info['command']
+        extension = format_info['extension']
     except KeyError:
         raise ui.UserError(
             u'convert: format {0} needs "command" and "extension" fields'
             .format(format)
         )
+    except ConfigTypeError:
+        command = config['convert']['formats'][format].get(str)
+        extension = format
+
+    # Convenience and backwards-compatibility shortcuts.
+    keys = config['convert'].keys()
+    if 'command' in keys:
+        command = config['convert']['command'].get(unicode)
+    elif 'opts' in keys:
+        # Undocumented option for backwards compatibility with < 1.3.1.
+        command = u'ffmpeg -i $source -y {0} $dest'.format(
+            config['convert']['opts'].get(unicode)
+        )
+    if 'extension' in keys:
+        extension = config['convert']['extension'].get(unicode)
+
+    return (command.encode('utf8'), extension.encode('utf8'))
 
 
-def encode(source, dest, pretend=False):
-    """Encode ``source`` to ``dest`` using the command from ``get_format()``.
+def encode(command, source, dest, pretend=False):
+    """Encode `source` to `dest` using command template `command`.
 
-    Raises an ``ui.UserError`` if the command was not found and a
-    ``subprocess.CalledProcessError`` if the command exited with a
+    Raises `subprocess.CalledProcessError` if the command exited with a
     non-zero status code.
     """
     quiet = config['convert']['quiet'].get()
@@ -95,7 +92,6 @@ def encode(source, dest, pretend=False):
     if not quiet and not pretend:
         log.info(u'Started encoding {0}'.format(util.displayable_path(source)))
 
-    command, _ = get_format()
     command = Template(command).safe_substitute({
         'source': pipes.quote(source),
         'dest':   pipes.quote(dest),
@@ -117,7 +113,7 @@ def encode(source, dest, pretend=False):
         raise
     except OSError as exc:
         raise ui.UserError(
-            u'convert: could invoke ffmpeg: {0}'.format(exc)
+            u"convert: could invoke '{0}': {0}".format(command, exc)
         )
 
     if not quiet and not pretend:
@@ -136,16 +132,22 @@ def should_transcode(item):
         item.bitrate >= 1000 * maxbr
 
 
-def convert_item(dest_dir, keep_new, path_formats, pretend=False):
+def convert_item(dest_dir, keep_new, path_formats, command, ext,
+                 pretend=False):
     while True:
         item = yield
-        dest = _destination(dest_dir, item, keep_new, path_formats)
+        dest = item.destination(basedir=dest_dir, path_formats=path_formats)
 
-        if os.path.exists(util.syspath(dest)):
-            log.info(u'Skipping {0} (target file exists)'.format(
-                util.displayable_path(item.path)
-            ))
-            continue
+        # When keeping the new file in the library, we first move the
+        # current (pristine) file to the destination. We'll then copy it
+        # back to its old path or transcode it to a new path.
+        if keep_new:
+            original = dest
+            converted = replace_ext(item.path, ext)
+        else:
+            original = item.path
+            dest = replace_ext(dest, ext)
+            converted = dest
 
         # Ensure that only one thread tries to create directories at a
         # time. (The existence check is not atomic with the directory
@@ -153,19 +155,16 @@ def convert_item(dest_dir, keep_new, path_formats, pretend=False):
         with _fs_lock:
             util.mkdirall(dest, pretend)
 
-        # When keeping the new file in the library, we first move the
-        # current (pristine) file to the destination. We'll then copy it
-        # back to its old path or transcode it to a new path.
+        if os.path.exists(util.syspath(dest)):
+            log.info(u'Skipping {0} (target file exists)'.format(
+                util.displayable_path(item.path)
+            ))
+            continue
+
         if keep_new:
             log.info(u'Moving to {0}'.
-                     format(util.displayable_path(dest)))
-            util.move(item.path, dest, pretend)
-            original = dest
-            _, ext = get_format()
-            converted = os.path.splitext(item.path)[0] + ext
-        else:
-            original = item.path
-            converted = dest
+                     format(util.displayable_path(original)))
+            util.move(item.path, original, pretend)
 
         if not should_transcode(item):
             # No transcoding necessary.
@@ -173,7 +172,7 @@ def convert_item(dest_dir, keep_new, path_formats, pretend=False):
             util.copy(original, converted, pretend)
         else:
             try:
-                encode(original, converted, pretend)
+                encode(command, original, converted, pretend)
             except subprocess.CalledProcessError:
                 continue
 
@@ -204,12 +203,12 @@ def convert_on_import(lib, item):
     library.
     """
     if should_transcode(item):
-        _, ext = get_format()
+        command, ext = get_format()
         fd, dest = tempfile.mkstemp(ext)
         os.close(fd)
         _temp_files.append(dest)  # Delete the transcode later.
         try:
-            encode(item.path, dest)
+            encode(command, item.path, dest)
         except subprocess.CalledProcessError:
             return
         item.path = dest
@@ -219,21 +218,24 @@ def convert_on_import(lib, item):
 
 
 def convert_func(lib, opts, args):
-    dest = opts.dest if opts.dest is not None else \
-        config['convert']['dest'].get()
-
-    if not dest:
+    if not opts.dest:
+        opts.dest = config['convert']['dest'].get()
+    if not opts.dest:
         raise ui.UserError('no convert destination set')
+    opts.dest = util.bytestring_path(opts.dest)
 
-    dest = util.bytestring_path(dest)
-    threads = opts.threads if opts.threads is not None else \
-        config['convert']['threads'].get(int)
-    keep_new = opts.keep_new
+    if not opts.threads:
+        opts.threads = config['convert']['threads'].get(int)
 
-    if not config['convert']['paths']:
-        path_formats = ui.get_path_formats()
-    else:
+    if config['convert']['paths']:
         path_formats = ui.get_path_formats(config['convert']['paths'])
+    else:
+        path_formats = ui.get_path_formats()
+
+    if not opts.format:
+        opts.format = config['convert']['format'].get(unicode).lower()
+
+    command, ext = get_format(opts.format)
 
     pretend = opts.pretend if opts.pretend is not None else \
         config['convert']['pretend'].get()
@@ -248,8 +250,13 @@ def convert_func(lib, opts, args):
         items = (i for a in lib.albums(ui.decargs(args)) for i in a.items())
     else:
         items = iter(lib.items(ui.decargs(args)))
-    convert = [convert_item(dest, keep_new, path_formats, pretend)
-               for _ in range(threads)]
+    convert = [convert_item(opts.dest,
+                            opts.keep_new,
+                            path_formats,
+                            command,
+                            ext,
+                            pretend)
+               for _ in range(opts.threads)]
     pipe = util.pipeline.Pipeline([items, convert])
     pipe.run_parallel()
 
@@ -272,29 +279,14 @@ class ConvertPlugin(BeetsPlugin):
                     u'command': u'ffmpeg -i $source -y -vn -acodec alac $dest',
                     u'extension': u'm4a',
                 },
-                u'flac': {
-                    u'command': u'ffmpeg -i $source -y -vn -acodec flac $dest',
-                    u'extension': u'flac',
-                },
-                u'mp3': {
-                    u'command': u'ffmpeg -i $source -y -vn -aq 2 $dest',
-                    u'extension': u'mp3',
-                },
-                u'opus': {
-                    u'command': u'ffmpeg -i $source -y -vn -acodec libopus '
-                                u'-ab 96k $dest',
-                    u'extension': u'opus',
-                },
-                u'ogg': {
-                    u'command': u'ffmpeg -i $source -y -vn -acodec libvorbis '
-                                u'-aq 2 $dest',
-                    u'extension': u'ogg',
-                },
-                u'windows media': {
-                    u'command': u'ffmpeg -i $source -y -vn -acodec wmav2 '
-                                u'-vn $dest',
-                    u'extension': u'wma',
-                },
+                u'flac': u'ffmpeg -i $source -y -vn -acodec flac $dest',
+                u'mp3': u'ffmpeg -i $source -y -vn -aq 2 $dest',
+                u'opus':
+                    u'ffmpeg -i $source -y -vn -acodec libopus -ab 96k $dest',
+                u'ogg':
+                    u'ffmpeg -i $source -y -vn -acodec libvorbis -aq 2 $dest',
+                u'wma':
+                    u'ffmpeg -i $source -y -vn -acodec wmav2 -vn $dest',
             },
             u'max_bitrate': 500,
             u'auto': False,
@@ -318,6 +310,8 @@ class ConvertPlugin(BeetsPlugin):
                               and move the old files')
         cmd.parser.add_option('-d', '--dest', action='store',
                               help='set the destination directory')
+        cmd.parser.add_option('-f', '--format', action='store', dest='format',
+                              help='set the destination directory')
         cmd.func = convert_func
         return [cmd]
 
diff --git a/docs/changelog.rst b/docs/changelog.rst
index 26e095cd0..74ce6195b 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -67,6 +67,8 @@ Little improvements and fixes:
   import.
 * :doc:`/plugins/chroma`: A new ``auto`` configuration option disables
   fingerprinting on import. Thanks to ddettrittus.
+* :doc:`/plugins/convert`: Add ``--format`` option to select the
+  transoding command from the command-line.
 
 
 1.3.6 (May 10, 2014)
diff --git a/docs/plugins/convert.rst b/docs/plugins/convert.rst
index 5eff02f1e..485c80400 100644
--- a/docs/plugins/convert.rst
+++ b/docs/plugins/convert.rst
@@ -4,23 +4,17 @@ Convert Plugin
 The ``convert`` plugin lets you convert parts of your collection to a
 directory of your choice, transcoding audio and embedding album art along the
 way. It can transcode to and from any format using a configurable command
-line. It will skip files that are already present in the target directory.
-Converted files follow the same path formats as your library.
-
-.. _FFmpeg: http://ffmpeg.org
+line.
 
 
 Installation
 ------------
 
-First, enable the ``convert`` plugin (see :doc:`/plugins/index`).
+Enable the ``convert`` plugin in your configuration (see
+:doc:`/plugins/index`).  By default, the plugin depends on `FFmpeg`_ to
+transcode the audio, so you might want to install it.
 
-To transcode music, this plugin requires the ``ffmpeg`` command-line
-tool. If its executable is in your path, it  will be found automatically
-by the plugin. Otherwise, configure the plugin to locate the executable::
-
-    convert:
-        ffmpeg: /usr/bin/ffmpeg
+.. _FFmpeg: http://ffmpeg.org
 
 
 Usage
@@ -28,11 +22,22 @@ Usage
 
 To convert a part of your collection, run ``beet convert QUERY``. This
 will display all items matching ``QUERY`` and ask you for confirmation before
-starting the conversion. The ``-a`` (or ``--album``) option causes the command
+starting the conversion. The command will then transcode all the
+matching files to the destination directory given by the ``-d``
+(``--dest``) option or the ``dest`` configuration. The path layout
+mirrors that of your library, but it may be customized through the
+``paths`` configuration.
+
+The plugin uses a command-line program to transcode the audio. With the
+``-f`` (``--format``) option you can choose the transcoding command
+and customize the available commands
+:ref:`through the configuration <convert-format-config>`.
+
+The ``-a`` (or ``--album``) option causes the command
 to match albums instead of tracks.
 
-The ``-t`` (``--threads``) and ``-d`` (``--dest``) options allow you to specify
-or overwrite the respective configuration options.
+The ``-t`` (``--threads``) option allows you to specify or overwrite
+the respective configuration option.
 
 By default, the command places converted files into the destination directory
 and leaves your library pristine. To instead back up your original files into
@@ -48,7 +53,7 @@ The plugin offers several configuration options, all of which live under the
 
 * ``dest`` sets the directory the files will be converted (or copied) to.
   A destination is required---you either have to provide it in the config file
-  or on the command line using the ``-d`` flag.
+  or on the command-line using the ``-d`` flag.
 * ``embed`` indicates whether or not to embed album art in converted items.
   Default: true.
 * If you set ``max_bitrate``, all lossy files with a higher bitrate will be
@@ -69,39 +74,14 @@ The plugin offers several configuration options, all of which live under the
   encoding. By default, the plugin will detect the number of processors
   available and use them all.
 
-These config options control the transcoding process:
+.. _convert-format-config:
 
-* ``format`` is the name of the audio file format to transcode to. Files that
-  are already in the format (and are below the maximum bitrate) will not be
-  transcoded. The plugin includes default commands for the formats MP3, AAC,
-  ALAC, FLAC, Opus, Vorbis, and Windows Media; the default is MP3. If you want
-  to use a different format (or customize the transcoding options), use the
-  options below.
-* ``extension`` is the filename extension to be used for newly transcoded
-  files. This is implied by the ``format`` option, but you can set it yourself
-  if you're using a different format.
-* ``command`` is the command line to use to transcode audio. A default
-  command, usually using an FFmpeg invocation, is implied by the ``format``
-  option. The tokens ``$source`` and ``$dest`` in the command are replaced
-  with the paths to the existing and new file. For example, the command
-  ``ffmpeg -i $source -y -aq 4 $dest`` transcodes to MP3 using FFmpeg at the
-  V4 quality level.
+Configuring the transcoding command
+```````````````````````````````````
 
-Here's an example configuration::
-
-    convert:
-        embed: false
-        format: aac
-        max_bitrate: 200
-        dest: /home/user/MusicForPhone
-        threads: 4
-        paths:
-            default: $albumartist/$title
-
-If you have several formats you want to switch between, you can list them
-under the ``formats`` key and refer to them using the ``format`` option. Each
-key under ``formats`` should contain values for ``command`` and ``extension``
-as described above::
+You can customize the transcoding command through the ``formats`` map
+and select a command with the ``--format`` command-line option or the
+``format`` configuration.::
 
     convert:
         format: speex
@@ -109,6 +89,28 @@ as described above::
             speex:
                 command: ffmpeg -i $source -y -acodec speex $dest
                 extension: spx
-            wav:
-                command: ffmpeg -i $source -y -acodec pcm_s16le $dest
-                extension: wav
+            wav: ffmpeg -i $source -y -acodec pcm_s16le $dest
+
+In this example ``beet convert`` will use the *speex* command by
+default. To convert the audio to `wav`, run ``beet convert -f wav``.
+This will also use the format key (`wav`) as the file extension.
+
+Each entry in the ``formats`` map consists of a key (the name of the
+format) as well as the command and the possibly the file extension.
+``extension`` is the filename extension to be used for newly transcoded
+files.  If only the command is given as a string, the file extension
+defaults to the format’s name. ``command`` is the command-line to use
+to transcode audio. The tokens ``$source`` and ``$dest`` in the command
+are replaced with the paths to the existing and new file.
+
+The plugin in comes with default commands for the most common audio
+formats: `mp3`, `alac`, `flac`, `aac`, `opus`, `ogg`, `wmv`. For
+details have a look at the output of ``beet config -d``.
+
+For a one-command-fits-all solution use the ``convert.command`` and
+``convert.extension`` options. If these are set the formats are ignored
+and the given command is used for all conversions.::
+
+    convert:
+        command: ffmpeg -i $source -y -vn -aq 2 $dest
+        extension: mp3
diff --git a/test/helper.py b/test/helper.py
index aa9c92add..4bcab88ad 100644
--- a/test/helper.py
+++ b/test/helper.py
@@ -180,24 +180,35 @@ class TestHelper(object):
         beets.plugins._instances = {}
 
     def create_importer(self, item_count=1, album_count=1):
-        """Returns import session with fixtures.
+        """Create files to import and return corresponding session.
 
         Copies the specified number of files to a subdirectory of
-        ``self.temp_dir`` and creates a ``TestImportSession`` for this
-        path.
+        `self.temp_dir` and creates a `TestImportSession` for this path.
         """
         import_dir = os.path.join(self.temp_dir, 'import')
         if not os.path.isdir(import_dir):
             os.mkdir(import_dir)
 
-        for i in range(album_count):
-            album = u'album {0}'.format(i)
+        album_no = 0
+        while album_count:
+            album = u'album {0}'.format(album_no)
             album_dir = os.path.join(import_dir, album)
+            if os.path.exists(album_dir):
+                album_no += 1
+                continue
             os.mkdir(album_dir)
-            for j in range(item_count):
-                title = 'track {0}'.format(j)
+            album_count -= 1
+
+            track_no = 0
+            album_item_count = item_count
+            while album_item_count:
+                title = 'track {0}'.format(track_no)
                 src = os.path.join(_common.RSRC, 'full.mp3')
                 dest = os.path.join(album_dir, '{0}.mp3'.format(title))
+                if os.path.exists(dest):
+                    track_no += 1
+                    continue
+                album_item_count -= 1
                 shutil.copy(src, dest)
                 mediafile = MediaFile(dest)
                 mediafile.update({
diff --git a/test/test_convert.py b/test/test_convert.py
index 21de94696..24ed44748 100644
--- a/test/test_convert.py
+++ b/test/test_convert.py
@@ -72,9 +72,18 @@ class ConvertCliTest(unittest.TestCase, TestHelper):
         self.load_plugins('convert')
 
         self.convert_dest = os.path.join(self.temp_dir, 'convert_dest')
-        self.config['convert']['dest'] = str(self.convert_dest)
-        self.config['convert']['command'] = u'cp $source $dest'
-        self.config['convert']['paths']['default'] = u'converted'
+        self.config['convert'] = {
+            'dest': self.convert_dest,
+            'paths': {'default': 'converted'},
+            'format': 'mp3',
+            'formats': {
+                'mp3': 'cp $source $dest',
+                'opus': {
+                    'command': 'cp $source $dest',
+                    'extension': 'ops',
+                }
+            }
+        }
 
     def tearDown(self):
         self.unload_plugins()
@@ -95,6 +104,12 @@ class ConvertCliTest(unittest.TestCase, TestHelper):
         self.item.load()
         self.assertEqual(os.path.splitext(self.item.path)[1], '.mp3')
 
+    def test_format_option(self):
+        with control_stdin('y'):
+            self.run_command('convert', '--format', 'opus', self.item.path)
+            converted = os.path.join(self.convert_dest, 'converted.ops')
+        self.assertTrue(os.path.isfile(converted))
+
     def test_embed_album_art(self):
         self.config['convert']['embed'] = True
         image_path = os.path.join(_common.RSRC, 'image-2x3.jpg')
diff --git a/test/test_importer.py b/test/test_importer.py
index 4f99e5157..80a94833a 100644
--- a/test/test_importer.py
+++ b/test/test_importer.py
@@ -1159,6 +1159,45 @@ class ResumeImportTest(unittest.TestCase, TestHelper):
         self.assertIsNotNone(self.lib.items('title:track 1').get())
 
 
+class IncrementalImportTest(unittest.TestCase, TestHelper):
+
+    def setUp(self):
+        self.setup_beets()
+        self.config['import']['incremental'] = True
+
+    def tearDown(self):
+        self.teardown_beets()
+
+    def test_incremental_album(self):
+        importer = self.create_importer(album_count=1)
+        importer.run()
+
+        # Change album name so the original file would be imported again
+        # if incremental was off.
+        album = self.lib.albums().get()
+        album['album'] = 'edited album'
+        album.store()
+
+        importer = self.create_importer(album_count=1)
+        importer.run()
+        self.assertEqual(len(self.lib.albums()), 2)
+
+    def test_incremental_item(self):
+        self.config['import']['singletons'] = True
+        importer = self.create_importer(item_count=1)
+        importer.run()
+
+        # Change track name so the original file would be imported again
+        # if incremental was off.
+        item = self.lib.items().get()
+        item['artist'] = 'edited artist'
+        item.store()
+
+        importer = self.create_importer(item_count=1)
+        importer.run()
+        self.assertEqual(len(self.lib.items()), 2)
+
+
 def suite():
     return unittest.TestLoader().loadTestsFromName(__name__)