Merge pull request #3100 from TheYokai/vgm_tagging

Improved `VGM` Metadata Tag Parsing. (GD3 Support)

quodlibet/quodlibet/formats/vgm.py

@@ -4,12 +4,31 @@
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.
-
-"""http://www.smspower.org/uploads/Music/vgmspec161.txt"""
-
 import struct
+import os
 
+from senf import path2fsn, fsn2text
 from ._audio import AudioFile, translate_errors
+from quodlibet.util.dprint import print_d
+from quodlibet.util import list_unique
+
+# VGM and GD3 SPECs:
+# http://www.smspower.org/uploads/Music/vgmspec170.txt
+# http://www.smspower.org/uploads/Music/gd3spec100.txt
+GD3_TAG_PTR_POS = 0x14
+GD3_TAG_PTR_SIZE = 4
+
+GD3_ENGLISH_TITLE = 0
+GD3_JAPANESE_TITLE = 1
+GD3_ENGLISH_GAME = 2
+GD3_JAPANESE_GAME = 3
+GD3_ENGLISH_SYSTEM = 4
+GD3_JAPANESE_SYSTEM = 5
+GD3_ENGLISH_ARTIST = 6
+GD3_JAPANESE_ARTIST = 7
+GD3_DATE = 8
+GD3_DUMPER = 9
+GD3_COMMENT = 10
 
 
 class VgmFile(AudioFile):
@@ -21,7 +40,8 @@ def __init__(self, filename):
             with open(filename, "rb") as h:
                 header = h.read(64)
                 if len(header) != 64 or header[:4] != b"Vgm ":
-                    raise Exception("Not a VGM file")
+                    # filename useful to show (helps w/ faulty VGM files.)
+                    raise Exception(filename + " not a VGM file")
 
                 samples_to_sec = lambda s: s / 44100.
                 samples = struct.unpack('<i', header[24:28])[0]
@@ -38,24 +58,90 @@ def __init__(self, filename):
 
                 self["~#length"] = length
 
+                gd3_position = struct.unpack('<i',
+                                             header[GD3_TAG_PTR_POS:
+                                                    GD3_TAG_PTR_POS
+                                                    + GD3_TAG_PTR_SIZE])[0]
+                h.seek(GD3_TAG_PTR_POS + gd3_position)
+                self.update(parse_gd3(h.read()))
+
+        self.setdefault(
+            "title", fsn2text(path2fsn(os.path.basename(filename)[:-4])))
         self.sanitize(filename)
 
     def write(self):
         pass
 
-    def reload(self, *args):
-        title = self.get("title")
-        super(VgmFile, self).reload(*args)
-        if title is not None:
-            self.setdefault("title", title)
-
     def can_change(self, k=None):
         if k is None:
             return ["title"]
         else:
             return k == "title"
 
 
+def parse_gd3(data):
+    tags = {}
+    if data[0:4] != b'Gd3 ':
+        print_d('Invalid Gd3, Missing Header...')
+        return tags
+
+    # version = data[4:8]
+    # Should be [0x00, 0x10, 0x00, 0x00] currently.
+    # We should hold onto it for possible branching if standards change.
+
+    gd3_length = struct.unpack('<i', data[8:12])[0]
+    # Length of gd3 footer. This means we can actually add more tags to the end
+    # with APETAG at some point. (Or at least consider...)
+
+    entries = data[12:12 + gd3_length].decode('utf-16-le').split('\0')
+
+    if len(entries) > GD3_JAPANESE_TITLE:
+        titles = gd3_filter_entries([entries[GD3_ENGLISH_TITLE],
+                                     entries[GD3_JAPANESE_TITLE]])
+        if len(titles) > 0:
+            tags["title"] = '\n'.join(titles)
+
+    if len(entries) > GD3_JAPANESE_ARTIST:
+        artists = gd3_filter_entries([entries[GD3_ENGLISH_ARTIST],
+                                      entries[GD3_JAPANESE_ARTIST]])
+        if len(artists) > 0:
+            tags["artist"] = '\n'.join(artists)
+
+    if len(entries) > GD3_JAPANESE_SYSTEM:
+        consoles = gd3_filter_entries([entries[GD3_ENGLISH_SYSTEM],
+                                       entries[GD3_JAPANESE_SYSTEM]])
+        if len(consoles) > 0:
+            tags["console"] = '\n'.join(consoles)
+
+    if len(entries) > GD3_JAPANESE_GAME:
+        games = gd3_filter_entries([entries[GD3_ENGLISH_GAME],
+                                    entries[GD3_JAPANESE_GAME]])
+        if len(games) > 0:
+            tags["album"] = '\n'.join(games)
+
+    if len(entries) > GD3_DATE and entries[GD3_DATE] != "":
+        tags["date"] = entries[GD3_DATE]
+
+    if len(entries) > GD3_DUMPER and entries[GD3_DUMPER] != "":
+        tags["dumper"] = entries[GD3_DUMPER]
+
+    if len(entries) > GD3_COMMENT:
+        tags["comment"] = entries[GD3_COMMENT]
+
+    return tags
+
+
+def gd3_filter_entries(entries):
+    # First, filter out empty strings...
+    filtered = list(filter(None, entries))
+    if len(filtered) == 0:
+        return filtered
+
+    # Then, filter out any duplicate strings...
+    filtered = list_unique(filtered)
+    return sorted(filtered)
+
+
 loader = VgmFile
 types = [VgmFile]
 extensions = [".vgm"]

quodlibet/tests/test_formats_vgm.py

@@ -19,7 +19,19 @@ def test_length(self):
     def test_reload(self):
         self.song["title"] = "foobar"
         self.song.reload()
-        self.failUnlessEqual(self.song("title"), "foobar")
+        self.failUnlessEqual(self.song("title"), "Chaos Emerald")
+
+    def test_gd3_tags(self):
+        expected_tags = {
+            "title": "Chaos Emerald",
+            "album": "Sonic the Hedgehog\nソニック・ザ・ヘッジホッグ",
+            "console": "Sega Mega Drive\nセガメガドライブ",
+            "artist": "Masato Nakamura\n中村正人",
+            "date": "1991"
+        }
+
+        for k, v in expected_tags.items():
+            self.failUnlessEqual(self.song[k], v)
 
     def test_write(self):
         self.song.write()