diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 4802aca4f1..de2c38b86a 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -47,9 +47,12 @@
         ([#8205](https://github.com/google/ExoPlayer/issues/8205)).
 *   Metadata retriever:
     *   Parse Google Photos HEIC motion photos metadata.
-*   FFMPEG extension:
-    *   Link the FFMPEG library statically, saving 350KB in binary size on
+*   FFmpeg extension:
+    *   Link the FFmpeg library statically, saving 350KB in binary size on
         average.
+*   Text:
+    *   Gracefully handle null-terminated subtitle content in Matroska
+        containers.
 
 ### 2.12.2 (2020-12-01) ###
 
diff --git a/library/core/src/test/java/com/google/android/exoplayer2/e2etest/MkvPlaybackTest.java b/library/core/src/test/java/com/google/android/exoplayer2/e2etest/MkvPlaybackTest.java
index b837255ffc..483b4aa3e5 100644
--- a/library/core/src/test/java/com/google/android/exoplayer2/e2etest/MkvPlaybackTest.java
+++ b/library/core/src/test/java/com/google/android/exoplayer2/e2etest/MkvPlaybackTest.java
@@ -45,7 +45,9 @@ public final class MkvPlaybackTest {
         "sample.mkv",
         "sample_with_htc_rotation_track_name.mkv",
         "sample_with_ssa_subtitles.mkv",
-        "sample_with_srt.mkv");
+        "sample_with_null_terminated_ssa_subtitles.mkv",
+        "sample_with_srt.mkv",
+        "sample_with_null_terminated_srt.mkv");
   }
 
   @ParameterizedRobolectricTestRunner.Parameter public String inputFile;
diff --git a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java
index af011fa751..e009dc97f1 100644
--- a/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java
+++ b/library/extractor/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java
@@ -1307,6 +1307,15 @@ public class MatroskaExtractor implements Extractor {
           Log.w(TAG, "Skipping subtitle sample with no duration.");
         } else {
           setSubtitleEndTime(track.codecId, blockDurationUs, subtitleSample.getData());
+          // The Matroska spec doesn't clearly define whether subtitle samples are null-terminated
+          // or the sample should instead be sized precisely. We truncate the sample at a null-byte
+          // to gracefully handle null-terminated strings followed by garbage bytes.
+          for (int i = subtitleSample.getPosition(); i < subtitleSample.limit(); i++) {
+            if (subtitleSample.getData()[i] == 0) {
+              subtitleSample.setLimit(i);
+              break;
+            }
+          }
           // Note: If we ever want to support DRM protected subtitles then we'll need to output the
           // appropriate encryption data here.
           track.output.sampleData(subtitleSample, subtitleSample.limit());
diff --git a/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractorTest.java b/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractorTest.java
index 20d6435256..16bcfc2f76 100644
--- a/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractorTest.java
+++ b/library/extractor/src/test/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractorTest.java
@@ -46,12 +46,27 @@ public final class MatroskaExtractorTest {
         MatroskaExtractor::new, "media/mkv/sample_with_srt.mkv", simulationConfig);
   }
 
+  @Test
+  public void mkvSample_withNullTerminatedSubripSubtitles() throws Exception {
+    ExtractorAsserts.assertBehavior(
+        MatroskaExtractor::new, "media/mkv/sample_with_null_terminated_srt.mkv", simulationConfig);
+  }
+
   @Test
   public void mkvSample_withSsaSubtitles() throws Exception {
     ExtractorAsserts.assertBehavior(
         MatroskaExtractor::new, "media/mkv/sample_with_ssa_subtitles.mkv", simulationConfig);
   }
 
+  // https://github.com/google/ExoPlayer/pull/8265
+  @Test
+  public void mkvSample_withNullTerminatedSsaSubtitles() throws Exception {
+    ExtractorAsserts.assertBehavior(
+        MatroskaExtractor::new,
+        "media/mkv/sample_with_null_terminated_ssa_subtitles.mkv",
+        simulationConfig);
+  }
+
   @Test
   public void mkvSample_withHtcRotationInfoInTrackName() throws Exception {
     ExtractorAsserts.assertBehavior(
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.0.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.0.dump
new file mode 100644
index 0000000000..ccf35b8c27
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.0.dump
@@ -0,0 +1,281 @@
+seekMap:
+  isSeekable = true
+  duration = 1234000
+  getPosition(0) = [[timeUs=0, position=1163]]
+  getPosition(1) = [[timeUs=0, position=1163]]
+  getPosition(617000) = [[timeUs=0, position=1163]]
+  getPosition(1234000) = [[timeUs=0, position=1163]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 67000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 33000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 200000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 133000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 100000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 167000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 333000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 267000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 233000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 300000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 433000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 400000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 367000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 567000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 500000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 467000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 533000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 700000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 633000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 600000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 667000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 833000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 767000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 733000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 800000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 967000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 900000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 867000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 933000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 62000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 97000
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 131000
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 166000
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 201000
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 236000
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 270000
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 306000
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 341000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 376000
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 410000
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 445000
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 480000
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 514000
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 550000
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 585000
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 620000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 654000
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 690000
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 724000
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 759000
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 793000
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 829000
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 864000
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 898000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 932000
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 968000
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1002000
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1037000
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 49
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = application/x-subrip
+    selectionFlags = 1
+    language = en
+    label = Subs Label
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 49, hash DE7F89EF
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.1.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.1.dump
new file mode 100644
index 0000000000..ccf35b8c27
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.1.dump
@@ -0,0 +1,281 @@
+seekMap:
+  isSeekable = true
+  duration = 1234000
+  getPosition(0) = [[timeUs=0, position=1163]]
+  getPosition(1) = [[timeUs=0, position=1163]]
+  getPosition(617000) = [[timeUs=0, position=1163]]
+  getPosition(1234000) = [[timeUs=0, position=1163]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 67000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 33000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 200000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 133000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 100000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 167000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 333000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 267000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 233000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 300000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 433000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 400000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 367000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 567000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 500000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 467000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 533000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 700000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 633000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 600000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 667000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 833000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 767000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 733000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 800000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 967000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 900000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 867000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 933000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 62000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 97000
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 131000
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 166000
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 201000
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 236000
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 270000
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 306000
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 341000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 376000
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 410000
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 445000
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 480000
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 514000
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 550000
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 585000
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 620000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 654000
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 690000
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 724000
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 759000
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 793000
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 829000
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 864000
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 898000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 932000
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 968000
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1002000
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1037000
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 49
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = application/x-subrip
+    selectionFlags = 1
+    language = en
+    label = Subs Label
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 49, hash DE7F89EF
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.2.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.2.dump
new file mode 100644
index 0000000000..ccf35b8c27
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.2.dump
@@ -0,0 +1,281 @@
+seekMap:
+  isSeekable = true
+  duration = 1234000
+  getPosition(0) = [[timeUs=0, position=1163]]
+  getPosition(1) = [[timeUs=0, position=1163]]
+  getPosition(617000) = [[timeUs=0, position=1163]]
+  getPosition(1234000) = [[timeUs=0, position=1163]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 67000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 33000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 200000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 133000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 100000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 167000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 333000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 267000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 233000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 300000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 433000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 400000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 367000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 567000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 500000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 467000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 533000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 700000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 633000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 600000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 667000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 833000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 767000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 733000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 800000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 967000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 900000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 867000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 933000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 62000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 97000
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 131000
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 166000
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 201000
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 236000
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 270000
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 306000
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 341000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 376000
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 410000
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 445000
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 480000
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 514000
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 550000
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 585000
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 620000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 654000
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 690000
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 724000
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 759000
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 793000
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 829000
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 864000
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 898000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 932000
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 968000
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1002000
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1037000
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 49
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = application/x-subrip
+    selectionFlags = 1
+    language = en
+    label = Subs Label
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 49, hash DE7F89EF
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.3.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.3.dump
new file mode 100644
index 0000000000..ccf35b8c27
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.3.dump
@@ -0,0 +1,281 @@
+seekMap:
+  isSeekable = true
+  duration = 1234000
+  getPosition(0) = [[timeUs=0, position=1163]]
+  getPosition(1) = [[timeUs=0, position=1163]]
+  getPosition(617000) = [[timeUs=0, position=1163]]
+  getPosition(1234000) = [[timeUs=0, position=1163]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 67000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 33000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 200000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 133000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 100000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 167000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 333000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 267000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 233000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 300000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 433000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 400000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 367000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 567000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 500000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 467000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 533000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 700000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 633000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 600000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 667000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 833000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 767000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 733000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 800000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 967000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 900000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 867000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 933000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 62000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 97000
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 131000
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 166000
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 201000
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 236000
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 270000
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 306000
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 341000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 376000
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 410000
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 445000
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 480000
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 514000
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 550000
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 585000
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 620000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 654000
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 690000
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 724000
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 759000
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 793000
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 829000
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 864000
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 898000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 932000
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 968000
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1002000
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1037000
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 49
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = application/x-subrip
+    selectionFlags = 1
+    language = en
+    label = Subs Label
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 49, hash DE7F89EF
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.unknown_length.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.unknown_length.dump
new file mode 100644
index 0000000000..ccf35b8c27
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_srt.mkv.unknown_length.dump
@@ -0,0 +1,281 @@
+seekMap:
+  isSeekable = true
+  duration = 1234000
+  getPosition(0) = [[timeUs=0, position=1163]]
+  getPosition(1) = [[timeUs=0, position=1163]]
+  getPosition(617000) = [[timeUs=0, position=1163]]
+  getPosition(1234000) = [[timeUs=0, position=1163]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 67000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 33000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 200000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 133000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 100000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 167000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 333000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 267000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 233000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 300000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 433000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 400000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 367000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 567000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 500000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 467000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 533000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 700000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 633000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 600000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 667000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 833000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 767000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 733000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 800000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 967000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 900000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 867000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 933000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 62000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 97000
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 131000
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 166000
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 201000
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 236000
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 270000
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 306000
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 341000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 376000
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 410000
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 445000
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 480000
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 514000
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 550000
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 585000
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 620000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 654000
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 690000
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 724000
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 759000
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 793000
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 829000
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 864000
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 898000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 932000
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 968000
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1002000
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1037000
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 49
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = application/x-subrip
+    selectionFlags = 1
+    language = en
+    label = Subs Label
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 49, hash DE7F89EF
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.0.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.0.dump
new file mode 100644
index 0000000000..ec1eaf729b
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.0.dump
@@ -0,0 +1,283 @@
+seekMap:
+  isSeekable = true
+  duration = 1139000
+  getPosition(0) = [[timeUs=0, position=6106]]
+  getPosition(1) = [[timeUs=0, position=6106], [timeUs=67000, position=6106]]
+  getPosition(569500) = [[timeUs=67000, position=6106]]
+  getPosition(1139000) = [[timeUs=67000, position=6106]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 67000
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 134000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 100000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 267000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 200000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 167000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 234000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 400000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 334000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 300000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 367000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 500000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 467000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 434000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 634000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 567000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 534000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 600000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 767000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 700000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 667000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 734000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 900000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 834000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 800000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 867000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 1034000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 967000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 934000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 1000000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 129000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 163829
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 198659
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 233489
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 268319
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 303149
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 337979
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 372809
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 408000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 442829
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 477659
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 512489
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 547319
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 582149
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 616979
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 651809
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 687000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 721829
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 756659
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 791489
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 826319
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 861149
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 895979
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 930809
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 965000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 999829
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 1034659
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1069489
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1104319
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 71
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = text/x-ssa
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 90, hash A5E21974
+      data = length 470, hash 40E7D996
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 71, hash 2B8E631C
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.1.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.1.dump
new file mode 100644
index 0000000000..ec1eaf729b
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.1.dump
@@ -0,0 +1,283 @@
+seekMap:
+  isSeekable = true
+  duration = 1139000
+  getPosition(0) = [[timeUs=0, position=6106]]
+  getPosition(1) = [[timeUs=0, position=6106], [timeUs=67000, position=6106]]
+  getPosition(569500) = [[timeUs=67000, position=6106]]
+  getPosition(1139000) = [[timeUs=67000, position=6106]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 67000
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 134000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 100000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 267000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 200000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 167000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 234000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 400000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 334000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 300000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 367000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 500000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 467000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 434000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 634000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 567000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 534000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 600000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 767000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 700000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 667000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 734000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 900000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 834000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 800000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 867000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 1034000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 967000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 934000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 1000000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 129000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 163829
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 198659
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 233489
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 268319
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 303149
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 337979
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 372809
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 408000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 442829
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 477659
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 512489
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 547319
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 582149
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 616979
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 651809
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 687000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 721829
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 756659
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 791489
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 826319
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 861149
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 895979
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 930809
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 965000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 999829
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 1034659
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1069489
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1104319
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 71
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = text/x-ssa
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 90, hash A5E21974
+      data = length 470, hash 40E7D996
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 71, hash 2B8E631C
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.2.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.2.dump
new file mode 100644
index 0000000000..ec1eaf729b
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.2.dump
@@ -0,0 +1,283 @@
+seekMap:
+  isSeekable = true
+  duration = 1139000
+  getPosition(0) = [[timeUs=0, position=6106]]
+  getPosition(1) = [[timeUs=0, position=6106], [timeUs=67000, position=6106]]
+  getPosition(569500) = [[timeUs=67000, position=6106]]
+  getPosition(1139000) = [[timeUs=67000, position=6106]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 67000
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 134000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 100000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 267000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 200000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 167000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 234000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 400000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 334000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 300000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 367000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 500000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 467000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 434000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 634000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 567000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 534000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 600000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 767000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 700000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 667000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 734000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 900000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 834000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 800000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 867000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 1034000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 967000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 934000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 1000000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 129000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 163829
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 198659
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 233489
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 268319
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 303149
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 337979
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 372809
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 408000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 442829
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 477659
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 512489
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 547319
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 582149
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 616979
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 651809
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 687000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 721829
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 756659
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 791489
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 826319
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 861149
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 895979
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 930809
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 965000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 999829
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 1034659
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1069489
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1104319
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 71
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = text/x-ssa
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 90, hash A5E21974
+      data = length 470, hash 40E7D996
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 71, hash 2B8E631C
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.3.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.3.dump
new file mode 100644
index 0000000000..ec1eaf729b
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.3.dump
@@ -0,0 +1,283 @@
+seekMap:
+  isSeekable = true
+  duration = 1139000
+  getPosition(0) = [[timeUs=0, position=6106]]
+  getPosition(1) = [[timeUs=0, position=6106], [timeUs=67000, position=6106]]
+  getPosition(569500) = [[timeUs=67000, position=6106]]
+  getPosition(1139000) = [[timeUs=67000, position=6106]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 67000
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 134000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 100000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 267000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 200000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 167000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 234000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 400000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 334000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 300000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 367000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 500000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 467000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 434000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 634000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 567000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 534000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 600000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 767000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 700000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 667000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 734000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 900000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 834000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 800000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 867000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 1034000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 967000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 934000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 1000000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 129000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 163829
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 198659
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 233489
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 268319
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 303149
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 337979
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 372809
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 408000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 442829
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 477659
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 512489
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 547319
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 582149
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 616979
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 651809
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 687000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 721829
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 756659
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 791489
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 826319
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 861149
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 895979
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 930809
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 965000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 999829
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 1034659
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1069489
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1104319
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 71
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = text/x-ssa
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 90, hash A5E21974
+      data = length 470, hash 40E7D996
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 71, hash 2B8E631C
+tracksEnded = true
diff --git a/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.unknown_length.dump b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.unknown_length.dump
new file mode 100644
index 0000000000..ec1eaf729b
--- /dev/null
+++ b/testdata/src/test/assets/extractordumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.unknown_length.dump
@@ -0,0 +1,283 @@
+seekMap:
+  isSeekable = true
+  duration = 1139000
+  getPosition(0) = [[timeUs=0, position=6106]]
+  getPosition(1) = [[timeUs=0, position=6106], [timeUs=67000, position=6106]]
+  getPosition(569500) = [[timeUs=67000, position=6106]]
+  getPosition(1139000) = [[timeUs=67000, position=6106]]
+numberOfTracks = 3
+track 1:
+  total output bytes = 89502
+  sample count = 30
+  format 0:
+    id = 1
+    sampleMimeType = video/avc
+    width = 1080
+    height = 720
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 30, hash F6F3D010
+      data = length 10, hash 7A0D0F2B
+  sample 0:
+    time = 67000
+    flags = 1
+    data = length 36477, hash F0F36CFE
+  sample 1:
+    time = 134000
+    flags = 0
+    data = length 5341, hash 40B85E2
+  sample 2:
+    time = 100000
+    flags = 0
+    data = length 596, hash 357B4D92
+  sample 3:
+    time = 267000
+    flags = 0
+    data = length 7704, hash A39EDA06
+  sample 4:
+    time = 200000
+    flags = 0
+    data = length 989, hash 2813C72D
+  sample 5:
+    time = 167000
+    flags = 0
+    data = length 721, hash C50D1C73
+  sample 6:
+    time = 234000
+    flags = 0
+    data = length 519, hash 65FE1911
+  sample 7:
+    time = 400000
+    flags = 0
+    data = length 6160, hash E1CAC0EC
+  sample 8:
+    time = 334000
+    flags = 0
+    data = length 953, hash 7160C661
+  sample 9:
+    time = 300000
+    flags = 0
+    data = length 620, hash 7A7AE07C
+  sample 10:
+    time = 367000
+    flags = 0
+    data = length 405, hash 5CC7F4E7
+  sample 11:
+    time = 500000
+    flags = 0
+    data = length 4852, hash 9DB6979D
+  sample 12:
+    time = 467000
+    flags = 0
+    data = length 547, hash E31A6979
+  sample 13:
+    time = 434000
+    flags = 0
+    data = length 570, hash FEC40D00
+  sample 14:
+    time = 634000
+    flags = 0
+    data = length 5525, hash 7C478F7E
+  sample 15:
+    time = 567000
+    flags = 0
+    data = length 1082, hash DA07059A
+  sample 16:
+    time = 534000
+    flags = 0
+    data = length 807, hash 93478E6B
+  sample 17:
+    time = 600000
+    flags = 0
+    data = length 744, hash 9A8E6026
+  sample 18:
+    time = 767000
+    flags = 0
+    data = length 4732, hash C73B23C0
+  sample 19:
+    time = 700000
+    flags = 0
+    data = length 1004, hash 8A19A228
+  sample 20:
+    time = 667000
+    flags = 0
+    data = length 794, hash 8126022C
+  sample 21:
+    time = 734000
+    flags = 0
+    data = length 645, hash F08300E5
+  sample 22:
+    time = 900000
+    flags = 0
+    data = length 2684, hash 727FE378
+  sample 23:
+    time = 834000
+    flags = 0
+    data = length 787, hash 419A7821
+  sample 24:
+    time = 800000
+    flags = 0
+    data = length 649, hash 5C159346
+  sample 25:
+    time = 867000
+    flags = 0
+    data = length 509, hash F912D655
+  sample 26:
+    time = 1034000
+    flags = 0
+    data = length 1226, hash 29815C21
+  sample 27:
+    time = 967000
+    flags = 0
+    data = length 898, hash D997AD0A
+  sample 28:
+    time = 934000
+    flags = 0
+    data = length 476, hash A0423645
+  sample 29:
+    time = 1000000
+    flags = 0
+    data = length 486, hash DDF32CBB
+track 2:
+  total output bytes = 12120
+  sample count = 29
+  format 0:
+    id = 2
+    sampleMimeType = audio/ac3
+    channelCount = 1
+    sampleRate = 44100
+    selectionFlags = 1
+    language = und
+  sample 0:
+    time = 129000
+    flags = 1
+    data = length 416, hash 211F2286
+  sample 1:
+    time = 163829
+    flags = 1
+    data = length 418, hash 77425A86
+  sample 2:
+    time = 198659
+    flags = 1
+    data = length 418, hash A0FE5CA1
+  sample 3:
+    time = 233489
+    flags = 1
+    data = length 418, hash 2309B066
+  sample 4:
+    time = 268319
+    flags = 1
+    data = length 418, hash 928A653B
+  sample 5:
+    time = 303149
+    flags = 1
+    data = length 418, hash 3422F0CB
+  sample 6:
+    time = 337979
+    flags = 1
+    data = length 418, hash EFF43D5B
+  sample 7:
+    time = 372809
+    flags = 1
+    data = length 418, hash FC8093C7
+  sample 8:
+    time = 408000
+    flags = 1
+    data = length 418, hash CCC08A16
+  sample 9:
+    time = 442829
+    flags = 1
+    data = length 418, hash 2A6EE863
+  sample 10:
+    time = 477659
+    flags = 1
+    data = length 418, hash D69A9251
+  sample 11:
+    time = 512489
+    flags = 1
+    data = length 418, hash BCFB758D
+  sample 12:
+    time = 547319
+    flags = 1
+    data = length 418, hash 11B66799
+  sample 13:
+    time = 582149
+    flags = 1
+    data = length 418, hash C824D392
+  sample 14:
+    time = 616979
+    flags = 1
+    data = length 418, hash C167D872
+  sample 15:
+    time = 651809
+    flags = 1
+    data = length 418, hash 4221C855
+  sample 16:
+    time = 687000
+    flags = 1
+    data = length 418, hash 4D4FF934
+  sample 17:
+    time = 721829
+    flags = 1
+    data = length 418, hash 984AA025
+  sample 18:
+    time = 756659
+    flags = 1
+    data = length 418, hash BB788B46
+  sample 19:
+    time = 791489
+    flags = 1
+    data = length 418, hash 9EFBFD97
+  sample 20:
+    time = 826319
+    flags = 1
+    data = length 418, hash DF1A460C
+  sample 21:
+    time = 861149
+    flags = 1
+    data = length 418, hash 2BDB56A
+  sample 22:
+    time = 895979
+    flags = 1
+    data = length 418, hash CA230060
+  sample 23:
+    time = 930809
+    flags = 1
+    data = length 418, hash D2F19F41
+  sample 24:
+    time = 965000
+    flags = 1
+    data = length 418, hash AF392D79
+  sample 25:
+    time = 999829
+    flags = 1
+    data = length 418, hash C5D7F2A3
+  sample 26:
+    time = 1034659
+    flags = 1
+    data = length 418, hash 733A35AE
+  sample 27:
+    time = 1069489
+    flags = 1
+    data = length 418, hash DE46E5D3
+  sample 28:
+    time = 1104319
+    flags = 1
+    data = length 418, hash 56AB8D37
+track 3:
+  total output bytes = 71
+  sample count = 1
+  format 0:
+    id = 3
+    sampleMimeType = text/x-ssa
+    selectionFlags = 1
+    language = und
+    initializationData:
+      data = length 90, hash A5E21974
+      data = length 470, hash 40E7D996
+  sample 0:
+    time = 0
+    flags = 1
+    data = length 71, hash 2B8E631C
+tracksEnded = true
diff --git a/testdata/src/test/assets/media/mkv/sample_with_null_terminated_srt.mkv b/testdata/src/test/assets/media/mkv/sample_with_null_terminated_srt.mkv
new file mode 100644
index 0000000000..8a9298a7bc
Binary files /dev/null and b/testdata/src/test/assets/media/mkv/sample_with_null_terminated_srt.mkv differ
diff --git a/testdata/src/test/assets/media/mkv/sample_with_null_terminated_ssa_subtitles.mkv b/testdata/src/test/assets/media/mkv/sample_with_null_terminated_ssa_subtitles.mkv
new file mode 100644
index 0000000000..8a125b2d50
Binary files /dev/null and b/testdata/src/test/assets/media/mkv/sample_with_null_terminated_ssa_subtitles.mkv differ
diff --git a/testdata/src/test/assets/playbackdumps/mkv/sample_with_null_terminated_srt.mkv.dump b/testdata/src/test/assets/playbackdumps/mkv/sample_with_null_terminated_srt.mkv.dump
new file mode 100644
index 0000000000..9cae6de0ca
--- /dev/null
+++ b/testdata/src/test/assets/playbackdumps/mkv/sample_with_null_terminated_srt.mkv.dump
@@ -0,0 +1,65 @@
+MediaCodec (audio/ac3):
+  buffers.length = 30
+  buffers[0] = length 416, hash 211F2286
+  buffers[1] = length 418, hash 77425A86
+  buffers[2] = length 418, hash A0FE5CA1
+  buffers[3] = length 418, hash 2309B066
+  buffers[4] = length 418, hash 928A653B
+  buffers[5] = length 418, hash 3422F0CB
+  buffers[6] = length 418, hash EFF43D5B
+  buffers[7] = length 418, hash FC8093C7
+  buffers[8] = length 418, hash CCC08A16
+  buffers[9] = length 418, hash 2A6EE863
+  buffers[10] = length 418, hash D69A9251
+  buffers[11] = length 418, hash BCFB758D
+  buffers[12] = length 418, hash 11B66799
+  buffers[13] = length 418, hash C824D392
+  buffers[14] = length 418, hash C167D872
+  buffers[15] = length 418, hash 4221C855
+  buffers[16] = length 418, hash 4D4FF934
+  buffers[17] = length 418, hash 984AA025
+  buffers[18] = length 418, hash BB788B46
+  buffers[19] = length 418, hash 9EFBFD97
+  buffers[20] = length 418, hash DF1A460C
+  buffers[21] = length 418, hash 2BDB56A
+  buffers[22] = length 418, hash CA230060
+  buffers[23] = length 418, hash D2F19F41
+  buffers[24] = length 418, hash AF392D79
+  buffers[25] = length 418, hash C5D7F2A3
+  buffers[26] = length 418, hash 733A35AE
+  buffers[27] = length 418, hash DE46E5D3
+  buffers[28] = length 418, hash 56AB8D37
+  buffers[29] = length 0, hash 1
+MediaCodec (video/avc):
+  buffers.length = 31
+  buffers[0] = length 36477, hash F0F36CFE
+  buffers[1] = length 5341, hash 40B85E2
+  buffers[2] = length 596, hash 357B4D92
+  buffers[3] = length 7704, hash A39EDA06
+  buffers[4] = length 989, hash 2813C72D
+  buffers[5] = length 721, hash C50D1C73
+  buffers[6] = length 519, hash 65FE1911
+  buffers[7] = length 6160, hash E1CAC0EC
+  buffers[8] = length 953, hash 7160C661
+  buffers[9] = length 620, hash 7A7AE07C
+  buffers[10] = length 405, hash 5CC7F4E7
+  buffers[11] = length 4852, hash 9DB6979D
+  buffers[12] = length 547, hash E31A6979
+  buffers[13] = length 570, hash FEC40D00
+  buffers[14] = length 5525, hash 7C478F7E
+  buffers[15] = length 1082, hash DA07059A
+  buffers[16] = length 807, hash 93478E6B
+  buffers[17] = length 744, hash 9A8E6026
+  buffers[18] = length 4732, hash C73B23C0
+  buffers[19] = length 1004, hash 8A19A228
+  buffers[20] = length 794, hash 8126022C
+  buffers[21] = length 645, hash F08300E5
+  buffers[22] = length 2684, hash 727FE378
+  buffers[23] = length 787, hash 419A7821
+  buffers[24] = length 649, hash 5C159346
+  buffers[25] = length 509, hash F912D655
+  buffers[26] = length 1226, hash 29815C21
+  buffers[27] = length 898, hash D997AD0A
+  buffers[28] = length 476, hash A0423645
+  buffers[29] = length 486, hash DDF32CBB
+  buffers[30] = length 0, hash 1
diff --git a/testdata/src/test/assets/playbackdumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.dump b/testdata/src/test/assets/playbackdumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.dump
new file mode 100644
index 0000000000..9cae6de0ca
--- /dev/null
+++ b/testdata/src/test/assets/playbackdumps/mkv/sample_with_null_terminated_ssa_subtitles.mkv.dump
@@ -0,0 +1,65 @@
+MediaCodec (audio/ac3):
+  buffers.length = 30
+  buffers[0] = length 416, hash 211F2286
+  buffers[1] = length 418, hash 77425A86
+  buffers[2] = length 418, hash A0FE5CA1
+  buffers[3] = length 418, hash 2309B066
+  buffers[4] = length 418, hash 928A653B
+  buffers[5] = length 418, hash 3422F0CB
+  buffers[6] = length 418, hash EFF43D5B
+  buffers[7] = length 418, hash FC8093C7
+  buffers[8] = length 418, hash CCC08A16
+  buffers[9] = length 418, hash 2A6EE863
+  buffers[10] = length 418, hash D69A9251
+  buffers[11] = length 418, hash BCFB758D
+  buffers[12] = length 418, hash 11B66799
+  buffers[13] = length 418, hash C824D392
+  buffers[14] = length 418, hash C167D872
+  buffers[15] = length 418, hash 4221C855
+  buffers[16] = length 418, hash 4D4FF934
+  buffers[17] = length 418, hash 984AA025
+  buffers[18] = length 418, hash BB788B46
+  buffers[19] = length 418, hash 9EFBFD97
+  buffers[20] = length 418, hash DF1A460C
+  buffers[21] = length 418, hash 2BDB56A
+  buffers[22] = length 418, hash CA230060
+  buffers[23] = length 418, hash D2F19F41
+  buffers[24] = length 418, hash AF392D79
+  buffers[25] = length 418, hash C5D7F2A3
+  buffers[26] = length 418, hash 733A35AE
+  buffers[27] = length 418, hash DE46E5D3
+  buffers[28] = length 418, hash 56AB8D37
+  buffers[29] = length 0, hash 1
+MediaCodec (video/avc):
+  buffers.length = 31
+  buffers[0] = length 36477, hash F0F36CFE
+  buffers[1] = length 5341, hash 40B85E2
+  buffers[2] = length 596, hash 357B4D92
+  buffers[3] = length 7704, hash A39EDA06
+  buffers[4] = length 989, hash 2813C72D
+  buffers[5] = length 721, hash C50D1C73
+  buffers[6] = length 519, hash 65FE1911
+  buffers[7] = length 6160, hash E1CAC0EC
+  buffers[8] = length 953, hash 7160C661
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