feat(uploader): generate cover for video

cps/uploader.py

@@ -18,6 +18,7 @@
 
 import os
 import hashlib
+import subprocess
 from tempfile import gettempdir
 from flask_babel import gettext as _
 
@@ -84,6 +85,9 @@ def process(tmp_file_path, original_file_name, original_file_extension, rarExecu
                                         original_file_name,
                                         original_file_extension,
                                         rarExecutable)
+        elif ".WEBM" == extension_upper or ".MP4" == extension_upper:
+            meta = video_metadata(tmp_file_path, original_file_name, original_file_extension)
+
     except Exception as ex:
         log.warning('cannot parse metadata, using default: %s', ex)
 
@@ -238,7 +242,36 @@ def pdf_preview(tmp_file_path, tmp_dir):
         log.warning('On Windows this error could be caused by missing ghostscript')
         return None
 
-
+def video_metadata(tmp_file_path, original_file_name, original_file_extension):
+    video_cover(tmp_file_path)
+    meta = BookMeta(
+        file_path=tmp_file_path,
+        extension=original_file_extension,
+        title=original_file_name,
+        author='Unknown',
+        cover=os.path.splitext(tmp_file_path)[0] + '.cover.jpg',
+        description='',
+        tags='',
+        series="",
+        series_id="",
+        languages="",
+        publisher="",
+        pubdate="",
+        identifiers=[])
+    return meta
+    
+def video_cover(tmp_file_path):
+    """ generate cover image from video using ffmpeg """
+    ffmpeg_executable = os.getenv('FFMPEG_PATH', 'ffmpeg')
+    try:
+        subprocess.call([ffmpeg_executable, '-i', tmp_file_path, '-vframes', '1', '-y', os.path.splitext(tmp_file_path)[0] + '.cover.jpg'])
+        tmp_file_path = os.path.splitext(tmp_file_path)[0] + '.cover.jpg'
+        return tmp_file_path
+    except Exception as ex:
+        log.warning('Cannot extract cover image, using default: %s', ex)
+        return None
+    
+    
 def get_magick_version():
     ret = dict()
     if not use_generic_pdf_cover: