Adds WebMClusterParserTest coverage for duration default/estimation/fallback logic

media/formats/webm/webm_cluster_parser_unittest.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <algorithm>
+#include <cstdlib>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "media/base/decrypt_config.h"
 #include "media/formats/webm/cluster_builder.h"
 #include "media/formats/webm/webm_cluster_parser.h"
 #include "media/formats/webm/webm_constants.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using ::testing::InSequence;
 using ::testing::Return;
 using ::testing::_;
 
 namespace media {
 
+typedef WebMTracksParser::TextTracks TextTracks;

[acolwell GONE FROM CHROMIUM, 2014/04/15 00:32:24]

nit: How about "using" instead of a typedef?

[wolenetz, 2014/04/15 01:49:12]

using only worked as an alias. Keeping as typedef. see also this CL's messages
for details.

+
 enum {
   kTimecodeScale = 1000000,  // Timecode scale for millisecond timestamps.
   kAudioTrackNum = 1,
   kVideoTrackNum = 2,
   kTextTrackNum = 3,
+  kTestAudioFrameDefaultDurationInMs = 13,
+  kTestVideoFrameDefaultDurationInMs = 17
 };
 
+COMPILE_ASSERT(kTestAudioFrameDefaultDurationInMs !=
+                   WebMClusterParser::kDefaultAudioBufferDurationInMs,
+               test_default_is_same_as_estimation_fallback_audio_duration);
+COMPILE_ASSERT(kTestVideoFrameDefaultDurationInMs !=
+                   WebMClusterParser::kDefaultVideoBufferDurationInMs,
+               test_default_is_same_as_estimation_fallback_video_duration);
+
 struct BlockInfo {
   int track_num;
   int timestamp;
+
+  // Negative value is allowed only for block groups (not simple blocks) and
+  // directs CreateCluster() to exclude BlockDuration entry from the cluster for
+  // this BlockGroup. The absolute value is used for parser verification.
+  // For simple blocks, this value must be non-negative, and is used only for
+  // parser verification.
   int duration;
   bool use_simple_block;
 };
 
 static const BlockInfo kDefaultBlockInfo[] = {
   { kAudioTrackNum, 0, 23, true },
   { kAudioTrackNum, 23, 23, true },
   { kVideoTrackNum, 33, 34, true },  // Assumes not using DefaultDuration
   { kAudioTrackNum, 46, 23, true },
   { kVideoTrackNum, 67, 33, false },
   { kAudioTrackNum, 69, 23, false },
   { kVideoTrackNum, 100, 33, false },
 };
 
 static const uint8 kEncryptedFrame[] = {
   0x01,  // Block is encrypted
   0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08  // IV
 };
 
 static scoped_ptr<Cluster> CreateCluster(int timecode,
                                          const BlockInfo* block_info,
                                          int block_count) {
   ClusterBuilder cb;
   cb.SetClusterTimecode(0);
 
   for (int i = 0; i < block_count; i++) {
     uint8 data[] = { 0x00 };
     if (block_info[i].use_simple_block) {
+      CHECK_GE(block_info[i].duration, 0);
       cb.AddSimpleBlock(block_info[i].track_num,
                         block_info[i].timestamp,
                         0, data, sizeof(data));
       continue;
     }
 
-    CHECK_GE(block_info[i].duration, 0);
+    if (block_info[i].duration < 0) {
+      cb.AddBlockGroupWithoutBlockDuration(block_info[i].track_num,
+                                           block_info[i].timestamp,
+                                           0, data, sizeof(data));
+      continue;
+    }
+
     cb.AddBlockGroup(block_info[i].track_num,
                      block_info[i].timestamp,
                      block_info[i].duration,
                      0, data, sizeof(data));
   }
 
   return cb.Finish();
 }
 
 // Creates a Cluster with one encrypted Block. |bytes_to_write| is number of
@@ skipping 37 matching lines @@
       LOG(ERROR) << "Unexpected track number " << block_info[i].track_num;
       return false;
     }
 
     if (*offset >= buffers->size())
       return false;
 
     scoped_refptr<StreamParserBuffer> buffer = (*buffers)[(*offset)++];
 
     EXPECT_EQ(block_info[i].timestamp, buffer->timestamp().InMilliseconds());
-    EXPECT_EQ(block_info[i].duration, buffer->duration().InMilliseconds());
+    EXPECT_EQ(std::abs(block_info[i].duration),
+              buffer->duration().InMilliseconds());
     EXPECT_EQ(expected_type, buffer->type());
     EXPECT_EQ(block_info[i].track_num, buffer->track_id());
   }
 
   return true;
 }
 
 static bool VerifyBuffers(const scoped_ptr<WebMClusterParser>& parser,
                           const BlockInfo* block_info,
                           int block_count) {
@@ skipping 29 matching lines @@
     const BlockInfo& block_info = *block_info_ptr++;
 
     if (block_info.track_num != text_track_num)
       continue;
 
     EXPECT_FALSE(block_info.use_simple_block);
     EXPECT_FALSE(buffer_iter == buffer_end);
 
     const scoped_refptr<StreamParserBuffer> buffer = *buffer_iter++;
     EXPECT_EQ(block_info.timestamp, buffer->timestamp().InMilliseconds());
-    EXPECT_EQ(block_info.duration, buffer->duration().InMilliseconds());
+    EXPECT_EQ(std::abs(block_info.duration),
+              buffer->duration().InMilliseconds());
     EXPECT_EQ(DemuxerStream::TEXT, buffer->type());
     EXPECT_EQ(text_track_num, buffer->track_id());
   }
 
   EXPECT_TRUE(buffer_iter == buffer_end);
   return true;
 }
 
 static void VerifyEncryptedBuffer(
     scoped_refptr<StreamParserBuffer> buffer) {
@@ skipping 11 matching lines @@
 }
 
 class WebMClusterParserTest : public testing::Test {
  public:
   WebMClusterParserTest()
       : parser_(new WebMClusterParser(kTimecodeScale,
                                       kAudioTrackNum,
                                       kNoTimestamp(),
                                       kVideoTrackNum,
                                       kNoTimestamp(),
-                                      WebMTracksParser::TextTracks(),
+                                      TextTracks(),
                                       std::set<int64>(),
                                       std::string(),
                                       std::string(),
                                       LogCB())) {}
 
  protected:
+  void ResetParserToHaveDefaultDurations() {
+    base::TimeDelta default_audio_duration = base::TimeDelta::FromMilliseconds(
+        kTestAudioFrameDefaultDurationInMs);
+    base::TimeDelta default_video_duration = base::TimeDelta::FromMilliseconds(
+        kTestVideoFrameDefaultDurationInMs);
+    ASSERT_GE(default_audio_duration, base::TimeDelta());
+    ASSERT_GE(default_video_duration, base::TimeDelta());
+    ASSERT_NE(kNoTimestamp(), default_audio_duration);
+    ASSERT_NE(kNoTimestamp(), default_video_duration);
+
+    parser_.reset(new WebMClusterParser(kTimecodeScale,
+                                        kAudioTrackNum,
+                                        default_audio_duration,
+                                        kVideoTrackNum,
+                                        default_video_duration,
+                                        TextTracks(),
+                                        std::set<int64>(),
+                                        std::string(),
+                                        std::string(),
+                                        LogCB()));
+  }
+
   scoped_ptr<WebMClusterParser> parser_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WebMClusterParserTest);
 };
 
 TEST_F(WebMClusterParserTest, Reset) {
   InSequence s;
 
   int block_count = arraysize(kDefaultBlockInfo);
   scoped_ptr<Cluster> cluster(CreateCluster(0, kDefaultBlockInfo, block_count));
 
   // Send slightly less than the full cluster so all but the last block is
   // parsed.
@@ skipping 106 matching lines @@
 
 TEST_F(WebMClusterParserTest, IgnoredTracks) {
   std::set<int64> ignored_tracks;
   ignored_tracks.insert(kTextTrackNum);
 
   parser_.reset(new WebMClusterParser(kTimecodeScale,
                                       kAudioTrackNum,
                                       kNoTimestamp(),
                                       kVideoTrackNum,
                                       kNoTimestamp(),
-                                      WebMTracksParser::TextTracks(),
+                                      TextTracks(),
                                       ignored_tracks,
                                       std::string(),
                                       std::string(),
                                       LogCB()));
 
   const BlockInfo kInputBlockInfo[] = {
     { kAudioTrackNum, 0,  23, true },
     { kAudioTrackNum, 23, 23, true },
     { kVideoTrackNum, 33, 34, true },
     { kTextTrackNum,  33, 99, true },
@@ skipping 13 matching lines @@
 
   scoped_ptr<Cluster> cluster(
       CreateCluster(0, kInputBlockInfo, input_block_count));
 
   int result = parser_->Parse(cluster->data(), cluster->size());
   EXPECT_EQ(cluster->size(), result);
   ASSERT_TRUE(VerifyBuffers(parser_, kOutputBlockInfo, output_block_count));
 }
 
 TEST_F(WebMClusterParserTest, ParseTextTracks) {
-  typedef WebMTracksParser::TextTracks TextTracks;
   TextTracks text_tracks;
 
   text_tracks.insert(std::make_pair(TextTracks::key_type(kTextTrackNum),
                                     TextTrackConfig(kTextSubtitles, "", "",
                                                     "")));
 
   parser_.reset(new WebMClusterParser(kTimecodeScale,
                                       kAudioTrackNum,
                                       kNoTimestamp(),
                                       kVideoTrackNum,
@@ skipping 17 matching lines @@
 
   scoped_ptr<Cluster> cluster(
       CreateCluster(0, kInputBlockInfo, input_block_count));
 
   int result = parser_->Parse(cluster->data(), cluster->size());
   EXPECT_EQ(cluster->size(), result);
   ASSERT_TRUE(VerifyBuffers(parser_, kInputBlockInfo, input_block_count));
 }
 
 TEST_F(WebMClusterParserTest, TextTracksSimpleBlock) {
-  typedef WebMTracksParser::TextTracks TextTracks;
-  WebMTracksParser::TextTracks text_tracks;
+  TextTracks text_tracks;
 
   text_tracks.insert(std::make_pair(TextTracks::key_type(kTextTrackNum),
                                     TextTrackConfig(kTextSubtitles, "", "",
                                                     "")));
 
   parser_.reset(new WebMClusterParser(kTimecodeScale,
                                       kAudioTrackNum,
                                       kNoTimestamp(),
                                       kVideoTrackNum,
                                       kNoTimestamp(),
                                       text_tracks,
                                       std::set<int64>(),
                                       std::string(),
                                       std::string(),
                                       LogCB()));
 
   const BlockInfo kInputBlockInfo[] = {
     { kTextTrackNum,  33, 42, true },
   };
   int input_block_count = arraysize(kInputBlockInfo);
 
   scoped_ptr<Cluster> cluster(
       CreateCluster(0, kInputBlockInfo, input_block_count));
 
   int result = parser_->Parse(cluster->data(), cluster->size());
   EXPECT_LT(result, 0);
 }
 
 TEST_F(WebMClusterParserTest, ParseMultipleTextTracks) {
-  typedef WebMTracksParser::TextTracks TextTracks;
   TextTracks text_tracks;
 
   const int kSubtitleTextTrackNum = kTextTrackNum;
   const int kCaptionTextTrackNum = kTextTrackNum + 1;
 
   text_tracks.insert(std::make_pair(TextTracks::key_type(kSubtitleTextTrackNum),
                                     TextTrackConfig(kTextSubtitles, "", "",
                                                     "")));
 
   text_tracks.insert(std::make_pair(TextTracks::key_type(kCaptionTextTrackNum),
@@ skipping 28 matching lines @@
 
   int result = parser_->Parse(cluster->data(), cluster->size());
   EXPECT_EQ(cluster->size(), result);
 
   const WebMClusterParser::TextBufferQueueMap& text_map =
       parser_->GetTextBuffers();
   for (WebMClusterParser::TextBufferQueueMap::const_iterator itr =
            text_map.begin();
        itr != text_map.end();
        ++itr) {
-    const WebMTracksParser::TextTracks::const_iterator find_result =
+    const TextTracks::const_iterator find_result =
         text_tracks.find(itr->first);
     ASSERT_TRUE(find_result != text_tracks.end());
     ASSERT_TRUE(VerifyTextBuffers(parser_, kInputBlockInfo, input_block_count,
                                   itr->first, itr->second));
   }
 }
 
 TEST_F(WebMClusterParserTest, ParseEncryptedBlock) {
   scoped_ptr<Cluster> cluster(CreateEncryptedCluster(sizeof(kEncryptedFrame)));
 
   parser_.reset(new WebMClusterParser(kTimecodeScale,
                                       kAudioTrackNum,
                                       kNoTimestamp(),
                                       kVideoTrackNum,
                                       kNoTimestamp(),
-                                      WebMTracksParser::TextTracks(),
+                                      TextTracks(),
                                       std::set<int64>(),
                                       std::string(),
                                       "video_key_id",
                                       LogCB()));
   int result = parser_->Parse(cluster->data(), cluster->size());
   EXPECT_EQ(cluster->size(), result);
   ASSERT_EQ(1UL, parser_->GetVideoBuffers().size());
   scoped_refptr<StreamParserBuffer> buffer = parser_->GetVideoBuffers()[0];
   VerifyEncryptedBuffer(buffer);
 }
 
 TEST_F(WebMClusterParserTest, ParseBadEncryptedBlock) {
   scoped_ptr<Cluster> cluster(
       CreateEncryptedCluster(sizeof(kEncryptedFrame) - 1));
 
   parser_.reset(new WebMClusterParser(kTimecodeScale,
                                       kAudioTrackNum,
                                       kNoTimestamp(),
                                       kVideoTrackNum,
                                       kNoTimestamp(),
-                                      WebMTracksParser::TextTracks(),
+                                      TextTracks(),
                                       std::set<int64>(),
                                       std::string(),
                                       "video_key_id",
                                       LogCB()));
   int result = parser_->Parse(cluster->data(), cluster->size());
   EXPECT_EQ(-1, result);
 }
 
 TEST_F(WebMClusterParserTest, ParseInvalidZeroSizedCluster) {
   const uint8 kBuffer[] = {
     0x1F, 0x43, 0xB6, 0x75, 0x80,  // CLUSTER (size = 0)
   };
 
   EXPECT_EQ(-1, parser_->Parse(kBuffer, sizeof(kBuffer)));
 }
 
 TEST_F(WebMClusterParserTest, ParseInvalidUnknownButActuallyZeroSizedCluster) {
   const uint8 kBuffer[] = {
     0x1F, 0x43, 0xB6, 0x75, 0xFF,  // CLUSTER (size = "unknown")
     0x1F, 0x43, 0xB6, 0x75, 0x85,  // CLUSTER (size = 5)
   };
 
   EXPECT_EQ(-1, parser_->Parse(kBuffer, sizeof(kBuffer)));
 }
 
+TEST_F(WebMClusterParserTest, ParseInvalidTextBlockGroupWithoutDuration) {
+  // Text track frames must have explicitly specified BlockGroup BlockDurations.
+  TextTracks text_tracks;
+
+  text_tracks.insert(std::make_pair(TextTracks::key_type(kTextTrackNum),
+                                    TextTrackConfig(kTextSubtitles, "", "",
+                                                    "")));
+
+  parser_.reset(new WebMClusterParser(kTimecodeScale,
+                                      kAudioTrackNum,
+                                      kNoTimestamp(),
+                                      kVideoTrackNum,
+                                      kNoTimestamp(),
+                                      text_tracks,
+                                      std::set<int64>(),
+                                      std::string(),
+                                      std::string(),
+                                      LogCB()));
+
+  const BlockInfo kBlockInfo[] = {
+    { kTextTrackNum,  33, -42, false },
+  };
+  int block_count = arraysize(kBlockInfo);
+  scoped_ptr<Cluster> cluster(CreateCluster(0, kBlockInfo, block_count));
+  int result = parser_->Parse(cluster->data(), cluster->size());
+  EXPECT_LT(result, 0);
+}
+
+TEST_F(WebMClusterParserTest, ParseWithDefaultDurationsSimpleBlocks) {
+  InSequence s;
+  ResetParserToHaveDefaultDurations();
+
+  EXPECT_LT(kTestAudioFrameDefaultDurationInMs, 23);
+  EXPECT_LT(kTestVideoFrameDefaultDurationInMs, 33);
+
+  const BlockInfo kBlockInfo[] = {
+    { kAudioTrackNum, 0, kTestAudioFrameDefaultDurationInMs, true },
+    { kAudioTrackNum, 23, kTestAudioFrameDefaultDurationInMs, true },
+    { kVideoTrackNum, 33, kTestVideoFrameDefaultDurationInMs, true },
+    { kAudioTrackNum, 46, kTestAudioFrameDefaultDurationInMs, true },
+    { kVideoTrackNum, 67, kTestVideoFrameDefaultDurationInMs, true },
+    { kAudioTrackNum, 69, kTestAudioFrameDefaultDurationInMs, true },
+    { kVideoTrackNum, 100, kTestVideoFrameDefaultDurationInMs, true },
+  };
+
+  int block_count = arraysize(kBlockInfo);
+  scoped_ptr<Cluster> cluster(CreateCluster(0, kBlockInfo, block_count));
+
+  // Send slightly less than the full cluster so all but the last block is
+  // parsed. Though all the blocks are simple blocks, none should be held aside
+  // for duration estimation prior to end of cluster detection because all the
+  // tracks have DefaultDurations.
+  int result = parser_->Parse(cluster->data(), cluster->size() - 1);
+  EXPECT_GT(result, 0);
+  EXPECT_LT(result, cluster->size());
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo, block_count - 1));
+
+  parser_->Reset();
+
+  // Now parse a whole cluster to verify that all the blocks will get parsed.
+  result = parser_->Parse(cluster->data(), cluster->size());
+  EXPECT_EQ(cluster->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo, block_count));
+}
+
+TEST_F(WebMClusterParserTest, ParseWithoutAnyDurationsSimpleBlocks) {
+  InSequence s;
+
+  // Absent DefaultDuration information, SimpleBlock durations are derived from
+  // inter-buffer track timestamp delta if within the cluster, and are estimated
+  // as the highest duration seen so far if the last buffer in the track in the
+  // cluster (independently for each track in the cluster).
+  const BlockInfo kBlockInfo1[] = {
+    { kAudioTrackNum, 0, 23, true },
+    { kAudioTrackNum, 23, 22, true },
+    { kVideoTrackNum, 33, 33, true },
+    { kAudioTrackNum, 45, 23, true },
+    { kVideoTrackNum, 66, 34, true },
+    { kAudioTrackNum, 68, 23, true },  // Estimated from maximum audio dur
+    { kVideoTrackNum, 100, 34, true },  // Estimated from maximum video dur
+  };
+
+  int block_count1 = arraysize(kBlockInfo1);
+  scoped_ptr<Cluster> cluster1(CreateCluster(0, kBlockInfo1, block_count1));
+
+  // Send slightly less than the first full cluster so all but the last video
+  // block is parsed. Verify the last fully parsed audio and video buffer are
+  // both missing from the result (parser should hold them aside for duration
+  // estimation prior to end of cluster detection in the absence of
+  // DefaultDurations.)
+  int result = parser_->Parse(cluster1->data(), cluster1->size() - 1);
+  EXPECT_GT(result, 0);
+  EXPECT_LT(result, cluster1->size());
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo1, block_count1 - 3));
+  EXPECT_EQ(3UL, parser_->GetAudioBuffers().size());
+  EXPECT_EQ(1UL, parser_->GetVideoBuffers().size());
+
+  parser_->Reset();
+
+  // Now parse the full first cluster and verify all the blocks are parsed.
+  result = parser_->Parse(cluster1->data(), cluster1->size());
+  EXPECT_EQ(cluster1->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo1, block_count1));
+
+  // Verify that the estimated frame duration is tracked across clusters for
+  // each track.
+  const BlockInfo kBlockInfo2[] = {
+    { kAudioTrackNum, 200, 23, true },  // Estimate carries over across clusters
+    { kVideoTrackNum, 201, 34, true },  // Estimate carries over across clusters
+  };
+
+  int block_count2 = arraysize(kBlockInfo2);
+  scoped_ptr<Cluster> cluster2(CreateCluster(0, kBlockInfo2, block_count2));
+  result = parser_->Parse(cluster2->data(), cluster2->size());
+  EXPECT_EQ(cluster2->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo2, block_count2));
+}
+
+TEST_F(WebMClusterParserTest, ParseWithoutAnyDurationsBlockGroups) {
+  InSequence s;
+
+  // Absent DefaultDuration and BlockDuration information, BlockGroup block
+  // durations are derived from inter-buffer track timestamp delta if within the
+  // cluster, and are estimated as the highest duration seen so far if the last

[acolwell GONE FROM CHROMIUM, 2014/04/15 00:32:24]

Doesn't this become lowest w/ Dale's change?

[wolenetz, 2014/04/15 01:49:12]

Correct. In patch set 3, I've rebased onto his CL and reworked these tests'
expectations accordingly.

+  // buffer in the track in the cluster (independently for each track in the
+  // cluster).
+    const BlockInfo kBlockInfo1[] = {
+    { kAudioTrackNum, 0, -23, false },
+    { kAudioTrackNum, 23, -22, false },
+    { kVideoTrackNum, 33, -33, false },
+    { kAudioTrackNum, 45, -23, false },
+    { kVideoTrackNum, 66, -34, false },
+    { kAudioTrackNum, 68, -23, false },  // Estimated from maximum audio dur
+    { kVideoTrackNum, 100, -34, false },  // Estimated from maximum video dur
+  };
+
+  int block_count1 = arraysize(kBlockInfo1);
+  scoped_ptr<Cluster> cluster1(CreateCluster(0, kBlockInfo1, block_count1));
+
+  // Send slightly less than the first full cluster so all but the last video
+  // block is parsed. Verify the last fully parsed audio and video buffer are
+  // both missing from the result (parser should hold them aside for duration
+  // estimation prior to end of cluster detection in the absence of
+  // DefaultDurations.)
+  int result = parser_->Parse(cluster1->data(), cluster1->size() - 1);
+  EXPECT_GT(result, 0);
+  EXPECT_LT(result, cluster1->size());
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo1, block_count1 - 3));
+  EXPECT_EQ(3UL, parser_->GetAudioBuffers().size());
+  EXPECT_EQ(1UL, parser_->GetVideoBuffers().size());
+
+  parser_->Reset();
+
+  // Now parse the full first cluster and verify all the blocks are parsed.
+  result = parser_->Parse(cluster1->data(), cluster1->size());
+  EXPECT_EQ(cluster1->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo1, block_count1));
+
+  // Verify that the estimated frame duration is tracked across clusters for
+  // each track.
+  const BlockInfo kBlockInfo2[] = {
+    { kAudioTrackNum, 200, -23, false },
+    { kVideoTrackNum, 201, -34, false },
+  };
+
+  int block_count2 = arraysize(kBlockInfo2);
+  scoped_ptr<Cluster> cluster2(CreateCluster(0, kBlockInfo2, block_count2));
+  result = parser_->Parse(cluster2->data(), cluster2->size());
+  EXPECT_EQ(cluster2->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo2, block_count2));
+}
+
+// TODO(wolenetz): Is parser behavior correct? See http://crbug.com/363433.
+TEST_F(WebMClusterParserTest,
+       ParseWithDefaultDurationsBlockGroupsWithoutDurations) {
+  InSequence s;
+  ResetParserToHaveDefaultDurations();
+
+  EXPECT_LT(kTestAudioFrameDefaultDurationInMs, 23);
+  EXPECT_LT(kTestVideoFrameDefaultDurationInMs, 33);
+
+  const BlockInfo kBlockInfo[] = {
+    { kAudioTrackNum, 0, -kTestAudioFrameDefaultDurationInMs, false },
+    { kAudioTrackNum, 23, -kTestAudioFrameDefaultDurationInMs, false },
+    { kVideoTrackNum, 33, -kTestVideoFrameDefaultDurationInMs, false },
+    { kAudioTrackNum, 46, -kTestAudioFrameDefaultDurationInMs, false },
+    { kVideoTrackNum, 67, -kTestVideoFrameDefaultDurationInMs, false },
+    { kAudioTrackNum, 69, -kTestAudioFrameDefaultDurationInMs, false },
+    { kVideoTrackNum, 100, -kTestVideoFrameDefaultDurationInMs, false },
+  };
+
+  int block_count = arraysize(kBlockInfo);
+  scoped_ptr<Cluster> cluster(CreateCluster(0, kBlockInfo, block_count));
+
+  // Send slightly less than the full cluster so all but the last block is
+  // parsed. None should be held aside for duration estimation prior to end of
+  // cluster detection because all the tracks have DefaultDurations.
+  int result = parser_->Parse(cluster->data(), cluster->size() - 1);
+  EXPECT_GT(result, 0);
+  EXPECT_LT(result, cluster->size());
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo, block_count - 1));
+
+  parser_->Reset();
+
+  // Now parse a whole cluster to verify that all the blocks will get parsed.
+  result = parser_->Parse(cluster->data(), cluster->size());
+  EXPECT_EQ(cluster->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo, block_count));
+}
+
+TEST_F(WebMClusterParserTest,
+       ParseDegenerateClusterYieldsHardcodedEstimatedDurations) {
+  const BlockInfo kBlockInfo[] = {
+    {
+      kAudioTrackNum,
+      0,
+      WebMClusterParser::kDefaultAudioBufferDurationInMs,
+      true
+    }, {
+      kVideoTrackNum,
+      0,
+      WebMClusterParser::kDefaultVideoBufferDurationInMs,
+      true
+    },
+  };
+
+  int block_count = arraysize(kBlockInfo);
+  scoped_ptr<Cluster> cluster(CreateCluster(0, kBlockInfo, block_count));
+  int result = parser_->Parse(cluster->data(), cluster->size());
+  EXPECT_EQ(cluster->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo, block_count));
+}
+
+TEST_F(WebMClusterParserTest,
+       ParseDegenerateClusterWithDefaultDurationsYieldsDefaultDurations) {
+  ResetParserToHaveDefaultDurations();
+  EXPECT_LT(kTestAudioFrameDefaultDurationInMs, 23);
+  EXPECT_LT(kTestVideoFrameDefaultDurationInMs, 33);
+
+  const BlockInfo kBlockInfo[] = {
+    { kAudioTrackNum, 0, kTestAudioFrameDefaultDurationInMs, true },
+    { kVideoTrackNum, 0, kTestVideoFrameDefaultDurationInMs, true },
+  };
+
+  int block_count = arraysize(kBlockInfo);
+  scoped_ptr<Cluster> cluster(CreateCluster(0, kBlockInfo, block_count));
+  int result = parser_->Parse(cluster->data(), cluster->size());
+  EXPECT_EQ(cluster->size(), result);
+  ASSERT_TRUE(VerifyBuffers(parser_, kBlockInfo, block_count));
+}
+
 }  // namespace media