From dba798798b47b1231fdcca9cab748f18fbccf443 Mon Sep 17 00:00:00 2001
From: Sergio Garcia Murillo <sergio.garcia.murillo@gmail.com>
Date: Sat, 25 Apr 2020 23:09:48 +0200
Subject: [PATCH] Prevent seg fault when finalizing empty segment (#759)

Fixes #757.
---
 packager/media/formats/webm/segmenter.cc | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/packager/media/formats/webm/segmenter.cc b/packager/media/formats/webm/segmenter.cc
index e9efa6bc98..b3ffdcfb18 100644
--- a/packager/media/formats/webm/segmenter.cc
+++ b/packager/media/formats/webm/segmenter.cc
@@ -150,9 +150,11 @@ Status Segmenter::Initialize(const StreamInfo& info,
 }
 
 Status Segmenter::Finalize() {
-  uint64_t duration =
-      prev_sample_->pts() - first_timestamp_ + prev_sample_->duration();
-  segment_info_.set_duration(FromBmffTimestamp(duration));
+  if (prev_sample_) {
+    uint64_t duration =
+        prev_sample_->pts() - first_timestamp_ + prev_sample_->duration();
+    segment_info_.set_duration(FromBmffTimestamp(duration));
+  }
   return DoFinalize();
 }