mirror-yt: Support limiting video height

Users might want to download not the biggest version of a video, so we
support passing a video height limit into yt-dlp.

mirror-yt.py

@@ -11,8 +11,10 @@ import click
               help='Error out if one of the directories from the given list does not exist')
 @click.option('--base-dir', type=Path, default='.', show_default=True,
               help='Base directory where the channel directories get created')
+@click.option('--max-video-height', type=int,
+              help='Maximum height of the video e.g. 720 or 1080 to filter video formats by')
 @click.argument('CHANNEL_FILE', required=True)
-def download(allow_unknown, base_dir, channel_file):
+def download(allow_unknown, base_dir, max_video_height, channel_file):
     """Mirror channels from YouTube
 
     The list of channels needs to be provided via CHANNEL_FILE. The format of the file should be one channel per line.
@@ -58,8 +60,11 @@ def download(allow_unknown, base_dir, channel_file):
             '--download-archive', target_dir / '.archive',
             '--break-on-existing',
             '--write-thumbnail',
-            url
+            '--embed-thumbnail',
         ]
+        if max_video_height:
+            cmd.extend(['-f', f"bv*[height<={max_video_height}]+ba"])
+        cmd.append(url)
         p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, cwd=target_dir)
         prev_output = ''
         while p.poll() is None: