From b30627714196ef759a3900dcc24423c8ffd02bd4 Mon Sep 17 00:00:00 2001
From: Robin Neatherway <robin.neatherway@gmail.com>
Date: Wed, 12 Jul 2017 18:31:30 +0100
Subject: [PATCH] Avoid overriding smhd_payload

---
 youtube_dl/downloader/ism.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/youtube_dl/downloader/ism.py b/youtube_dl/downloader/ism.py
index eba1750de..9b001ecff 100644
--- a/youtube_dl/downloader/ism.py
+++ b/youtube_dl/downloader/ism.py
@@ -98,7 +98,7 @@ def write_piff_header(stream, params):
 
     if is_audio:
         smhd_payload = s88.pack(0)  # balance
-        smhd_payload = u16.pack(0)  # reserved
+        smhd_payload += u16.pack(0)  # reserved
         media_header_box = full_box(b'smhd', 0, 0, smhd_payload)  # Sound Media Header
     else:
         vmhd_payload = u16.pack(0)  # graphics mode