From 6298f49d9eea09d70987f3205139370a4cc51f58 Mon Sep 17 00:00:00 2001
From: akata01 <akata0612@gmail.com>
Date: Mon, 10 Aug 2020 01:44:16 +0000
Subject: [PATCH] Don't fail if input contents contain
 SampleGroupDescriptionBox with 0 entries

Fixes #812.
---
 packager/media/formats/mp4/box_definitions.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/packager/media/formats/mp4/box_definitions.cc b/packager/media/formats/mp4/box_definitions.cc
index ffbbb032b1..7bc205d276 100644
--- a/packager/media/formats/mp4/box_definitions.cc
+++ b/packager/media/formats/mp4/box_definitions.cc
@@ -1059,7 +1059,12 @@ bool SampleGroupDescription::ReadWriteEntries(BoxBuffer* buffer,
 
   uint32_t count = static_cast<uint32_t>(entries->size());
   RCHECK(buffer->ReadWriteUInt32(&count));
-  RCHECK(count != 0);
+  if (buffer->Reading()) {
+    if (count == 0)
+      return true;
+  } else {
+    RCHECK(count != 0);
+  }
   entries->resize(count);
 
   for (T& entry : *entries) {