From 4956b2dec65352af32dc71bab553acb631c64177 Mon Sep 17 00:00:00 2001
From: Tom Finegan <tomfinegan@google.com>
Date: Thu, 12 Jan 2017 13:15:46 -0800
Subject: [PATCH] mkvmuxer: Force new clusters when audio queue gets too long.

Force creation of a new Cluster when writing queued audio would
cause an error due to violating maximum block duration.

BUG=675521

Change-Id: I6ad09c2a2f71d95bb04eed5ead04dc8072aaa59d
---
 mkvmuxer/mkvmuxer.cc | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/mkvmuxer/mkvmuxer.cc b/mkvmuxer/mkvmuxer.cc
index 299b45c..8323ec7 100644
--- a/mkvmuxer/mkvmuxer.cc
+++ b/mkvmuxer/mkvmuxer.cc
@@ -3490,6 +3490,19 @@ bool Segment::AddGenericFrame(const Frame* frame) {
   if (frame->discard_padding() != 0)
     doc_type_version_ = 4;
 
+  if (cluster_list_size_ > 0) {
+    const uint64_t timecode_scale = segment_info_.timecode_scale();
+    const uint64_t frame_timecode = frame->timestamp() / timecode_scale;
+
+    const Cluster* const last_cluster = cluster_list_[cluster_list_size_ - 1];
+    const uint64_t last_cluster_timecode = last_cluster->timecode();
+
+    const uint64_t rel_timecode = frame_timecode - last_cluster_timecode;
+    if (rel_timecode > kMaxBlockTimecode) {
+      force_new_cluster_ = true;
+    }
+  }
+
   // If the segment has a video track hold onto audio frames to make sure the
   // audio that is associated with the start time of a video key-frame is
   // muxed into the same cluster.