From 5faf9fed7e1c7922578467cfd48db5867ef9b91b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sergey=20M=E2=80=A4?= <dstftw@gmail.com>
Date: Sat, 28 Nov 2015 18:50:21 +0600
Subject: [PATCH] [youtube] Clarify rationale for yt:stretch validation

---
 youtube_dl/extractor/youtube.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/youtube_dl/extractor/youtube.py b/youtube_dl/extractor/youtube.py
index 9da8d4bc5..1c2420a33 100644
--- a/youtube_dl/extractor/youtube.py
+++ b/youtube_dl/extractor/youtube.py
@@ -1514,6 +1514,8 @@ def _map_to_format_list(urlmap):
         if stretched_m:
             w = float(stretched_m.group('w'))
             h = float(stretched_m.group('h'))
+            # yt:stretch may hold invalid ratio data (e.g. for Q39EVAstoRM ratio is 17:0).
+            # We will only process correct ratios.
             if w > 0 and h > 0:
                 ratio = w / h
                 for f in formats: