From 418e741f7f46480dc0bfb8dae6c9e6654bf02483 Mon Sep 17 00:00:00 2001
From: KongQun Yang <kqyang@google.com>
Date: Thu, 21 Jun 2018 14:26:41 -0700
Subject: [PATCH] [DASH] Fix potential text Segment Timeline not grouped

This happens when --allow_approximate_segment_timeline_ is set.

Fixes #417.

Change-Id: Idf938ad4e0f7788a00c7485b7eeda43358a94178
---
 packager/mpd/base/representation.cc          |  2 +-
 packager/mpd/base/representation_unittest.cc | 40 +++++++++++++++++++-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/packager/mpd/base/representation.cc b/packager/mpd/base/representation.cc
index 44092d30bd..3883fc45d9 100644
--- a/packager/mpd/base/representation.cc
+++ b/packager/mpd/base/representation.cc
@@ -420,7 +420,7 @@ bool Representation::ApproximiatelyEqual(uint64_t time1, uint64_t time2) const {
       std::min(frame_duration_,
                static_cast<uint32_t>(kErrorThresholdSeconds *
                                      media_info_.reference_time_scale()));
-  return time1 < time2 + error_threshold && time2 < time1 + error_threshold;
+  return time1 <= time2 + error_threshold && time2 <= time1 + error_threshold;
 }
 
 uint64_t Representation::AdjustDuration(uint64_t duration) const {
diff --git a/packager/mpd/base/representation_unittest.cc b/packager/mpd/base/representation_unittest.cc
index 7fb55f4965..f7c24fc3c8 100644
--- a/packager/mpd/base/representation_unittest.cc
+++ b/packager/mpd/base/representation_unittest.cc
@@ -856,8 +856,8 @@ TEST_P(ApproximateSegmentTimelineTest, SegmentsWithSimilarDurations2) {
   std::string expected_s_elements;
   if (allow_approximate_segment_timeline_) {
     expected_s_elements =
-        "<S t=\"0\" d=\"10\"/>"
-        "<S t=\"10\" d=\"12\" r=\"1\"/>";
+        "<S t=\"0\" d=\"10\" r=\"1\"/>"
+        "<S t=\"20\" d=\"13\"/>";
   } else {
     uint64_t kNumSegments = 3;
     expected_s_elements = base::StringPrintf(kSElementTemplate, kStartTime,
@@ -915,6 +915,42 @@ TEST_P(ApproximateSegmentTimelineTest, FillSmallOverlap) {
               XmlNodeEqual(ExpectedXml(expected_s_elements)));
 }
 
+// Check the segments are grouped correctly when sample duration is not
+// available, which happens for text streams.
+// See https://github.com/google/shaka-packager/issues/417 for the background.
+TEST_P(ApproximateSegmentTimelineTest, NoSampleDuration) {
+  const char kMediaInfo[] =
+      "text_info {\n"
+      "  codec: 'wvtt'\n"
+      "}\n"
+      "reference_time_scale: 1000\n"
+      "container_type: 1\n"
+      "init_segment_url: 'init.mp4'\n"
+      "segment_template_url: '$Number$.mp4'\n";
+  representation_ = CreateRepresentation(ConvertToMediaInfo(kMediaInfo),
+                                         kAnyRepresentationId, NoListener());
+  ASSERT_TRUE(representation_->Init());
+
+  const uint64_t kStartTime = 0;
+  const uint64_t kDuration = kScaledTargetSegmentDuration;
+  const uint64_t kSize = 128;
+  AddSegments(kStartTime, kDuration, kSize, 0);
+  AddSegments(kStartTime + kDuration, kDuration, kSize, 0);
+  AddSegments(kStartTime + 2 * kDuration, kDuration, kSize, 0);
+
+  const char kExpectedXml[] =
+      "<Representation id=\"1\" bandwidth=\"102400\" codecs=\"wvtt\""
+      " mimeType=\"application/mp4\">\n"
+      "  <SegmentTemplate timescale=\"1000\" initialization=\"init.mp4\" "
+      "   media=\"$Number$.mp4\" startNumber=\"1\">\n"
+      "    <SegmentTimeline>\n"
+      "      <S t=\"0\" d=\"10\" r=\"2\"/>\n"
+      "     </SegmentTimeline>\n"
+      "  </SegmentTemplate>\n"
+      "</Representation>\n";
+  EXPECT_THAT(representation_->GetXml().get(), XmlNodeEqual(kExpectedXml));
+}
+
 INSTANTIATE_TEST_CASE_P(ApproximateSegmentTimelineTest,
                         ApproximateSegmentTimelineTest,
                         Bool());