[YoutubeDL] Add more numeric fields for NA substitution in outtmpl

diff --git a/youtube_dl/YoutubeDL.py b/youtube_dl/YoutubeDL.py
index fc5e67828aba8e8aa9fe9ad043630f65b9ecd89e..56a8691eb01d203c0f05a6a14f6855985fd1ab01 100755 (executable)
--- a/youtube_dl/YoutubeDL.py
+++ b/youtube_dl/YoutubeDL.py
@@ -635,6 +635,7 @@ class YoutubeDL(object):
                 'average_rating', 'comment_count', 'age_limit',
                 'start_time', 'end_time',
                 'chapter_number', 'season_number', 'episode_number',
+                'track_number', 'disc_number', 'release_year',
                 'playlist_index',
             ))