Bug 1513651 - Add gtest for MP4 metadata telemetry probes. r=chutten

Add a gtest to cover the new telemetry probes which collect info on sample
description entries.

Add a new init segment to those already in our gtests. This segment has data for
one video track, and covers the case where multiple sample description entries
are present for a single track. In this case, because separate sample
description entries are used for unencrypted and encrypted samples.

For reference, the test init segment was created from our existing bipbop using
shaka-packager via the following command (non-init segments were discarded and
the output was renamed):

packager-win.exe
in=bipbop.mp4,stream=video,init_segment=bipbop_cbcs_video_init.mp4,segment_template=bipbop_cbcs_video_$Number$.m4s
--protection_scheme cbcs --enable_raw_key_encryption  --keys
label=:key_id=7e571d047e571d047e571d047e571d21:key=7e5744447e5744447e5744447e574421
--iv 11223344556677889900112233445566 --generate_static_mpd --mpd_output
bipbop_cbcs.mpd

Depends on D14426

Differential Revision: https://phabricator.services.mozilla.com/D19386

--HG--
extra : moz-landing-system : lando

dom/media/gtest/mp4_demuxer/TestParser.cpp

@@ -7,9 +7,12 @@
 #include "MediaData.h"
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/Tuple.h"
 #include "BufferStream.h"
 #include "MP4Metadata.h"
 #include "MoofParser.h"
+#include "TelemetryFixture.h"
+#include "TelemetryTestHelpers.h"
 
 class TestStream;
 namespace mozilla {
@@ -767,3 +770,210 @@ TEST(MP4Metadata, EmptyCTTS) {
   EXPECT_TRUE(metadata.CanSeek());
   EXPECT_FALSE(metadata.Crypto().Ref()->valid);
 }
+
+// Fixture so we test telemetry probes.
+class MP4MetadataTelemetryFixture : public TelemetryTestFixture {};
+
+TEST_F(MP4MetadataTelemetryFixture, Telemetry) {
+  // Helper to fetch the metadata from a file and send telemetry in the process.
+  auto UpdateMetadataAndHistograms = [](const char* testFileName) {
+    nsTArray<uint8_t> buffer = ReadTestFile(testFileName);
+    ASSERT_FALSE(buffer.IsEmpty());
+    RefPtr<ByteStream> stream =
+        new TestStream(buffer.Elements(), buffer.Length());
+
+    MP4Metadata::ResultAndByteBuffer metadataBuffer =
+        MP4Metadata::Metadata(stream);
+    EXPECT_EQ(NS_OK, metadataBuffer.Result());
+    EXPECT_TRUE(metadataBuffer.Ref());
+
+    MP4Metadata metadata(stream);
+    nsresult res = metadata.Parse();
+    EXPECT_TRUE(NS_SUCCEEDED(res));
+    auto audioTrackCount = metadata.GetNumberTracks(TrackInfo::kAudioTrack);
+    ASSERT_NE(audioTrackCount.Ref(), MP4Metadata::NumberTracksError());
+    auto videoTrackCount = metadata.GetNumberTracks(TrackInfo::kVideoTrack);
+    ASSERT_NE(videoTrackCount.Ref(), MP4Metadata::NumberTracksError());
+
+    // Need to read the track data to get telemetry to fire.
+    for (uint32_t i = 0; i < audioTrackCount.Ref(); i++) {
+      metadata.GetTrackInfo(TrackInfo::kAudioTrack, i);
+    }
+    for (uint32_t i = 0; i < videoTrackCount.Ref(); i++) {
+      metadata.GetTrackInfo(TrackInfo::kVideoTrack, i);
+    }
+  };
+
+  AutoJSContextWithGlobal cx(mCleanGlobal);
+
+  // Checks the current state of the histograms relating to sample description
+  // entries and verifies they're in an expected state.
+  // aExpectedMultipleCodecCounts is a tuple where the first value represents
+  // the number of expected 'false' count, and the second the expected 'true'
+  // count for the sample description entries have multiple codecs histogram.
+  // aExpectedMultipleCryptoCounts is the same, but for the sample description
+  // entires have multiple crypto histogram.
+  // aExpectedSampleDescriptionEntryCounts is a tuple with 6 values, each is
+  // the expected number of sample description seen. I.e, the first value in the
+  // tuple is the number of tracks we've seen with 0 sample descriptions, the
+  // second value with 1 sample description, and so on up to 5 sample
+  // descriptions. aFileName is the name of the most recent file we've parsed,
+  // and is used to log if our telem counts are not in an expected state.
+  auto CheckHistograms =
+      [this, &cx](
+          const Tuple<uint32_t, uint32_t>& aExpectedMultipleCodecCounts,
+          const Tuple<uint32_t, uint32_t>& aExpectedMultipleCryptoCounts,
+          const Tuple<uint32_t, uint32_t, uint32_t, uint32_t, uint32_t,
+                      uint32_t>& aExpectedSampleDescriptionEntryCounts,
+          const char* aFileName) {
+        // Get a snapshot of the current histograms
+        JS::RootedValue snapshot(cx.GetJSContext());
+        TelemetryTestHelpers::GetSnapshots(cx.GetJSContext(), mTelemetry,
+                                           "" /* this string is unused */,
+                                           &snapshot, false /* is_keyed */);
+
+        // We'll use these to pull values out of the histograms.
+        JS::RootedValue values(cx.GetJSContext());
+        JS::RootedValue value(cx.GetJSContext());
+
+        // Verify our multiple codecs count histogram.
+        JS::RootedValue multipleCodecsHistogram(cx.GetJSContext());
+        TelemetryTestHelpers::GetProperty(
+            cx.GetJSContext(),
+            "MEDIA_MP4_PARSE_SAMPLE_DESCRIPTION_ENTRIES_HAVE_MULTIPLE_CODECS",
+            snapshot, &multipleCodecsHistogram);
+        ASSERT_TRUE(multipleCodecsHistogram.isObject())
+            << "Multiple codecs histogram should exist!";
+
+        TelemetryTestHelpers::GetProperty(cx.GetJSContext(), "values",
+                                          multipleCodecsHistogram, &values);
+        // False count.
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 0, values, &value);
+        uint32_t uValue = 0;
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<0>(aExpectedMultipleCodecCounts), uValue)
+            << "Unexpected number of false multiple codecs after parsing "
+            << aFileName;
+        // True count.
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 1, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<1>(aExpectedMultipleCodecCounts), uValue)
+            << "Unexpected number of true multiple codecs after parsing "
+            << aFileName;
+
+        // Verify our multiple crypto count histogram.
+        JS::RootedValue multipleCryptoHistogram(cx.GetJSContext());
+        TelemetryTestHelpers::GetProperty(
+            cx.GetJSContext(),
+            "MEDIA_MP4_PARSE_SAMPLE_DESCRIPTION_ENTRIES_HAVE_MULTIPLE_CRYPTO",
+            snapshot, &multipleCryptoHistogram);
+        ASSERT_TRUE(multipleCryptoHistogram.isObject())
+            << "Multiple crypto histogram should exist!";
+
+        TelemetryTestHelpers::GetProperty(cx.GetJSContext(), "values",
+                                          multipleCryptoHistogram, &values);
+        // False count.
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 0, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<0>(aExpectedMultipleCryptoCounts), uValue)
+            << "Unexpected number of false multiple cryptos after parsing "
+            << aFileName;
+        // True count.
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 1, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<1>(aExpectedMultipleCryptoCounts), uValue)
+            << "Unexpected number of true multiple cryptos after parsing "
+            << aFileName;
+
+        // Verify our sample description entry count histogram.
+        JS::RootedValue numSamplesHistogram(cx.GetJSContext());
+        TelemetryTestHelpers::GetProperty(
+            cx.GetJSContext(), "MEDIA_MP4_PARSE_NUM_SAMPLE_DESCRIPTION_ENTRIES",
+            snapshot, &numSamplesHistogram);
+        ASSERT_TRUE(numSamplesHistogram.isObject())
+            << "Num sample description entries histogram should exist!";
+
+        TelemetryTestHelpers::GetProperty(cx.GetJSContext(), "values",
+                                          numSamplesHistogram, &values);
+
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 0, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<0>(aExpectedSampleDescriptionEntryCounts), uValue)
+            << "Unexpected number of 0 sample entry descriptions after parsing "
+            << aFileName;
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 1, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<1>(aExpectedSampleDescriptionEntryCounts), uValue)
+            << "Unexpected number of 1 sample entry descriptions after parsing "
+            << aFileName;
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 2, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<2>(aExpectedSampleDescriptionEntryCounts), uValue)
+            << "Unexpected number of 2 sample entry descriptions after parsing "
+            << aFileName;
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 3, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<3>(aExpectedSampleDescriptionEntryCounts), uValue)
+            << "Unexpected number of 3 sample entry descriptions after parsing "
+            << aFileName;
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 4, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<4>(aExpectedSampleDescriptionEntryCounts), uValue)
+            << "Unexpected number of 4 sample entry descriptions after parsing "
+            << aFileName;
+        TelemetryTestHelpers::GetElement(cx.GetJSContext(), 5, values, &value);
+        JS::ToUint32(cx.GetJSContext(), value, &uValue);
+        EXPECT_EQ(Get<5>(aExpectedSampleDescriptionEntryCounts), uValue)
+            << "Unexpected number of 5 sample entry descriptions after parsing "
+            << aFileName;
+      };
+
+  // Clear histograms
+  TelemetryTestHelpers::GetAndClearHistogram(
+      cx.GetJSContext(), mTelemetry,
+      NS_LITERAL_CSTRING(
+          "MEDIA_MP4_PARSE_SAMPLE_DESCRIPTION_ENTRIES_HAVE_MULTIPLE_CODECS"),
+      false /* is_keyed */);
+
+  TelemetryTestHelpers::GetAndClearHistogram(
+      cx.GetJSContext(), mTelemetry,
+      NS_LITERAL_CSTRING(
+          "MEDIA_MP4_PARSE_SAMPLE_DESCRIPTION_ENTRIES_HAVE_MULTIPLE_CRYPTO"),
+      false /* is_keyed */);
+
+  TelemetryTestHelpers::GetAndClearHistogram(
+      cx.GetJSContext(), mTelemetry,
+      NS_LITERAL_CSTRING("MEDIA_MP4_PARSE_NUM_SAMPLE_DESCRIPTION_ENTRIES"),
+      false /* is_keyed */);
+
+  // The snapshot won't have any data in it until we populate our histograms, so
+  // we don't check for a baseline here. Just read out first MP4 metadata.
+
+  // Grab one of the test cases we know should parse and parse it, this should
+  // trigger telemetry gathering.
+
+  // This file contains 2 moovs, each with a video and audio track with one
+  // sample description entry. So we should see 4 tracks, each with a single
+  // codec, no crypto, and a single sample description entry.
+  UpdateMetadataAndHistograms("test_case_1185230.mp4");
+
+  // Verify our histograms are updated.
+  CheckHistograms(
+      MakeTuple<uint32_t, uint32_t>(4, 0), MakeTuple<uint32_t, uint32_t>(4, 0),
+      MakeTuple<uint32_t, uint32_t, uint32_t, uint32_t, uint32_t, uint32_t>(
+          0, 4, 0, 0, 0, 0),
+      "test_case_1185230.mp4");
+
+  // Parse another test case. This one has a single moov with a single video
+  // track. However, the track has two sample description entries, and our
+  // updated telemetry should reflect that.
+  UpdateMetadataAndHistograms(
+      "test_case_1513651-2-sample-description-entries.mp4");
+
+  // Verify our histograms are updated.
+  CheckHistograms(
+      MakeTuple<uint32_t, uint32_t>(5, 0), MakeTuple<uint32_t, uint32_t>(5, 0),
+      MakeTuple<uint32_t, uint32_t, uint32_t, uint32_t, uint32_t, uint32_t>(
+          0, 4, 1, 0, 0, 0),
+      "test_case_1513651-2-sample-description-entries.mp4");
+}

dom/media/gtest/mp4_demuxer/moz.build

@@ -42,6 +42,7 @@ TEST_HARNESS_FILES.gtest += [
     'test_case_1389527.mp4',
     'test_case_1395244.mp4',
     'test_case_1410565.mp4',
+    'test_case_1513651-2-sample-description-entries.mp4',
     'test_case_1519617-cenc-init-with-track_id-0.mp4',
     'test_case_1519617-track2-trafs-removed.mp4',
     'test_case_1519617-video-has-track_id-0.mp4',
@@ -53,6 +54,7 @@ TEST_HARNESS_FILES.gtest += [
 ]
 LOCAL_INCLUDES += [
     '../../mp4',
+    '/toolkit/components/telemetry/tests/gtest',
 ]
 
 FINAL_LIBRARY = 'xul-gtest'