From a43af01b6ba2f730206d6c334ca55e9cbbf04204 Mon Sep 17 00:00:00 2001
From: Thomas Scholtes <thomas-scholtes@gmx.de>
Date: Mon, 10 Feb 2014 16:28:48 +0100
Subject: [PATCH] Add storage style for MP4 images

---
 beets/mediafile.py           | 68 +++++++++++++++++++-----------------
 test/test_mediafile_basic.py | 10 +++---
 2 files changed, 41 insertions(+), 37 deletions(-)

diff --git a/beets/mediafile.py b/beets/mediafile.py
index 7d3b58056..b0de8aebe 100644
--- a/beets/mediafile.py
+++ b/beets/mediafile.py
@@ -519,6 +519,38 @@ class MP4BoolStorageStyle(MP4StorageStyle):
         raise NotImplementedError('MP4 bool storage does not support lists')
 
 
+class MP4ImageStorageStyle(MP4ListStorageStyle):
+
+    def __init__(self, **kwargs):
+        super(MP4ImageStorageStyle, self).__init__(key='covr', **kwargs)
+
+    def store(self, mediafile, images):
+        covers = [self._mp4_cover(image) for image in images]
+        mediafile.mgfile['covr'] = covers
+
+    @classmethod
+    def _mp4_cover(cls, data):
+        """Make ``MP4Cover`` tag from image data.
+
+        Returns instance of ``mutagen.mp4.MP4Cover`` with correct cover
+        format.
+        """
+        kind = imghdr.what(None, h=data)
+        if kind == 'png':
+            kind = mutagen.mp4.MP4Cover.FORMAT_PNG
+        if kind == 'jpg':
+            kind = mutagen.mp4.MP4Cover.FORMAT_JPEG
+        else:
+            kind = mutagen.mp4.MP4Cover.FORMAT_JPEG
+            # TODO use this later
+            # raise ValueError('MP4 only supports PNG and JPEG images')
+
+        return mutagen.mp4.MP4Cover(data, kind)
+
+    def serialize(self, value):
+        return bytearray(value)
+
+
 class MP3StorageStyle(StorageStyle):
 
     def __init__(self, key, id3_lang=None, **kwargs):
@@ -760,7 +792,7 @@ class ImageField(MediaField):
         super(ImageField, self).__init__(
             out_type=bytearray,
             mp3=MP3ImageStorageStyle(),
-            mp4=[],
+            mp4=MP4ImageStorageStyle(),
             asf=[],
             etc=[],
         )
@@ -777,33 +809,11 @@ class ImageField(MediaField):
             # Currently just fall back to JPEG.
             return 'image/jpeg'
 
-    @classmethod
-    def _mp4kind(cls, data):
-        """Return the MPEG-4 image type code of the data. If the image
-        is not a PNG or JPEG, JPEG is assumed.
-        """
-        kind = imghdr.what(None, h=data)
-        if kind == 'png':
-            return mutagen.mp4.MP4Cover.FORMAT_PNG
-        else:
-            return mutagen.mp4.MP4Cover.FORMAT_JPEG
-
     def __get__(self, obj, owner):
-        if obj.type == 'mp3':
+        if obj.type == 'mp3' or obj.type in MP4_TYPES:
             for style in self._styles(obj):
                 return style.get(obj)
 
-        elif obj.type in MP4_TYPES:
-            if 'covr' in obj.mgfile:
-                covers = obj.mgfile['covr']
-                if covers:
-                    cover = covers[0]
-                    # cover is an MP4Cover, which is a subclass of str.
-                    return cover
-
-            # No cover found.
-            return None
-
         elif obj.type == 'flac':
             pictures = obj.mgfile.pictures
             if pictures:
@@ -852,18 +862,10 @@ class ImageField(MediaField):
             if not isinstance(val, str):
                 raise ValueError('value must be a byte string or None')
 
-        if obj.type == 'mp3':
+        if obj.type == 'mp3' or obj.type in MP4_TYPES:
             for style in self._styles(obj):
                 style.set(obj, val)
 
-        elif obj.type in MP4_TYPES:
-            if val is None:
-                if 'covr' in obj.mgfile:
-                    del obj.mgfile['covr']
-            else:
-                cover = mutagen.mp4.MP4Cover(val, self._mp4kind(val))
-                obj.mgfile['covr'] = [cover]
-
         elif obj.type == 'flac':
             obj.mgfile.clear_pictures()
 
diff --git a/test/test_mediafile_basic.py b/test/test_mediafile_basic.py
index 77c179da1..f5646b83d 100644
--- a/test/test_mediafile_basic.py
+++ b/test/test_mediafile_basic.py
@@ -310,13 +310,15 @@ class ReadWriteTestBase(ArtTestMixin):
             base = self.empty_tags
 
         for key, value in base.items():
-            if isinstance(value, unicode) or key == 'art':
+            if key == 'art':
+                tags[key] = self.jpg_data
+            elif isinstance(value, unicode):
                 tags[key] = 'value %s' % key
-            if isinstance(value, int):
+            elif isinstance(value, int):
                 tags[key] = 1
-            if isinstance(value, float):
+            elif isinstance(value, float):
                 tags[key] = 1.0
-            if isinstance(value, bool):
+            elif isinstance(value, bool):
                 tags[key] = True
 
         date = datetime.date(2001, 4, 3)