Refine function added to utils to extract metadata from mkv files.

src/utils.py

@@ -2,9 +2,15 @@
 from datetime import datetime
 import hashlib
 import os
+import logging
 import re
 import struct
 
+from babelfish import Error as BabelfishError, Language
+from enzyme import MKV
+
+logger = logging.getLogger(__name__)
+
 def sanitize(string, ignore_characters=None):
     """Sanitize a string to strip special characters.
 
@@ -36,3 +42,89 @@ def sanitize(string, ignore_characters=None):
     # strip and lower case
     return string.strip().lower()
 
+
+def refine(video, embedded_subtitles=True, **kwargs):
+    """Refine a video by searching its metadata.
+    Several :class:`~subliminal.video.Video` attributes can be found:
+      * :attr:`~subliminal.video.Video.resolution`
+      * :attr:`~subliminal.video.Video.video_codec`
+      * :attr:`~subliminal.video.Video.audio_codec`
+      * :attr:`~subliminal.video.Video.subtitle_languages`
+    :param bool embedded_subtitles: search for embedded subtitles.
+    """
+    # skip non existing videos
+    if not video.exists:
+        return
+
+    # check extensions
+    extension = os.path.splitext(video.name)[1]
+    if extension == '.mkv':
+        with open(video.name, 'rb') as f:
+            mkv = MKV(f)
+
+        # main video track
+        if mkv.video_tracks:
+            video_track = mkv.video_tracks[0]
+
+            # resolution
+            if video_track.height in (480, 720, 1080):
+                if video_track.interlaced:
+                    video.resolution = '%di' % video_track.height
+                else:
+                    video.resolution = '%dp' % video_track.height
+                logger.debug('Found resolution %s', video.resolution)
+
+            # video codec
+            if video_track.codec_id == 'V_MPEG4/ISO/AVC':
+                video.video_codec = 'h264'
+                logger.debug('Found video_codec %s', video.video_codec)
+            elif video_track.codec_id == 'V_MPEG4/ISO/SP':
+                video.video_codec = 'DivX'
+                logger.debug('Found video_codec %s', video.video_codec)
+            elif video_track.codec_id == 'V_MPEG4/ISO/ASP':
+                video.video_codec = 'XviD'
+                logger.debug('Found video_codec %s', video.video_codec)
+        else:
+            logger.warning('MKV has no video track')
+
+        # main audio track
+        if mkv.audio_tracks:
+            audio_track = mkv.audio_tracks[0]
+            # audio codec
+            if audio_track.codec_id == 'A_AC3':
+                video.audio_codec = 'AC3'
+                logger.debug('Found audio_codec %s', video.audio_codec)
+            elif audio_track.codec_id == 'A_DTS':
+                video.audio_codec = 'DTS'
+                logger.debug('Found audio_codec %s', video.audio_codec)
+            elif audio_track.codec_id == 'A_AAC':
+                video.audio_codec = 'AAC'
+                logger.debug('Found audio_codec %s', video.audio_codec)
+        else:
+            logger.warning('MKV has no audio track')
+
+        # subtitle tracks
+        if mkv.subtitle_tracks:
+            if embedded_subtitles:
+                embedded_subtitle_languages = set()
+                for st in mkv.subtitle_tracks:
+                    if st.language:
+                        try:
+                            embedded_subtitle_languages.add(Language.fromalpha3b(st.language))
+                        except BabelfishError:
+                            logger.error('Embedded subtitle track language %r is not a valid language', st.language)
+                            embedded_subtitle_languages.add(Language('und'))
+                    elif st.name:
+                        try:
+                            embedded_subtitle_languages.add(Language.fromname(st.name))
+                        except BabelfishError:
+                            logger.debug('Embedded subtitle track name %r is not a valid language', st.name)
+                            embedded_subtitle_languages.add(Language('und'))
+                    else:
+                        embedded_subtitle_languages.add(Language('und'))
+                logger.debug('Found embedded subtitle %r', embedded_subtitle_languages)
+                video.subtitle_languages |= embedded_subtitle_languages
+        else:
+            logger.debug('MKV has no subtitle track')
+    else:
+        logger.debug('Unsupported video extension %s', extension)