Add test cases for CEA closed captions

Issue #1404

Change-Id: I35e679ef985ac5cef1f8d8673192845cae29b114

lib/media/media_source_engine.js

@@ -532,7 +532,7 @@ shaka.media.MediaSourceEngine.prototype.appendBuffer =
           return this.enqueueOperation_(contentType,
               this.append_.bind(this, contentType, transmuxedData.data.buffer));
         }.bind(this));
-  } else if (hasClosedCaptions) {
+  } else if (hasClosedCaptions && window.muxjs) {
     if (!this.textEngine_) {
       this.reinitText('text/vtt');
     }
@@ -1095,3 +1095,22 @@ shaka.media.MediaSourceEngine.prototype.popFromQueue_ = function(contentType) {
     }
   }
 };
+
+
+/**
+ * Set the closed caption parser. Used only for unit tests.
+ * @param {muxjs.mp4.CaptionParser} captionParser
+ */
+shaka.media.MediaSourceEngine.prototype.setCaptionParser = function(
+    captionParser) {
+  this.captionParser_ = captionParser;
+};
+
+
+/**
+ * Get the closed caption parser. Used only for unit tests.
+ * @return {muxjs.mp4.CaptionParser} captionParser
+ */
+shaka.media.MediaSourceEngine.prototype.getCaptionParser = function() {
+  return this.captionParser_;
+};

lib/text/text_engine.js

@@ -90,8 +90,16 @@ shaka.text.TextEngine.unregisterParser = function(mimeType) {
  * @return {boolean}
  */
 shaka.text.TextEngine.isTypeSupported = function(mimeType) {
-  return !!shaka.text.TextEngine.parserMap_[mimeType] ||
-      mimeType == shaka.util.MimeUtils.CLOSED_CAPTION_MIMETYPE;
+  if (shaka.text.TextEngine.parserMap_[mimeType]) {
+    // An actual parser is available.
+    return true;
+  }
+  if (window.muxjs &&
+      mimeType == shaka.util.MimeUtils.CLOSED_CAPTION_MIMETYPE) {
+    // Will be handled by mux.js.
+    return true;
+  }
+  return false;
 };
 
 

test/dash/dash_parser_manifest_unit.js

@@ -181,7 +181,6 @@ describe('DashParser Manifest', function() {
         .build());
   });
 
-
   it('skips any periods after one without duration', async () => {
     let periodContents = [
       '    <AdaptationSet mimeType="video/mp4" lang="en" group="1">',
@@ -359,7 +358,6 @@ describe('DashParser Manifest', function() {
     expect(stream3.closedCaptions).toEqual(expectedClosedCaptions);
   });
 
-
   it('correctly parses closed captions without channel numbers', async () => {
     const source = [
       '<MPD minBufferTime="PT75S">',
@@ -386,7 +384,6 @@ describe('DashParser Manifest', function() {
     expect(stream.closedCaptions).toEqual(expectedClosedCaptions);
   });
 
-
   it('correctly parses closed captions with no channel and language info',
       async () => {
     const source = [
@@ -410,7 +407,6 @@ describe('DashParser Manifest', function() {
     expect(stream.closedCaptions).toEqual(expectedClosedCaptions);
   });
 
-
   it('correctly parses UTF-8', async () => {
     let source = [
       '<MPD>',

test/media/media_source_engine_unit.js

@@ -72,6 +72,8 @@ describe('MediaSourceEngine', function() {
   let video;
   let mockMediaSource;
   let mockTextEngine;
+  /** @type {shaka.test.FakeCaptionParser} */
+  let mockCaptionParser;
   /** @type {!jasmine.Spy} */
   let createMediaSourceSpy;
 
@@ -143,6 +145,7 @@ describe('MediaSourceEngine', function() {
     };
     video = /** @type {HTMLMediaElement} */(mockVideo);
     mediaSourceEngine = new shaka.media.MediaSourceEngine(video);
+    mockCaptionParser = new shaka.test.FakeCaptionParser();
   });
 
   afterEach(function() {
@@ -524,6 +527,63 @@ describe('MediaSourceEngine', function() {
         videoSourceBuffer.updateend();
       });
     });
+
+    it('appends parsed closed captions from CaptionParser', async () => {
+      const initObject = new Map();
+      initObject.set(ContentType.VIDEO, fakeVideoStream);
+      await mediaSourceEngine.init(initObject, false);
+
+      mediaSourceEngine.setUseEmbeddedText(false);
+      // Initialize the closed caption parser.
+      const appendInit = mediaSourceEngine.appendBuffer(
+          ContentType.VIDEO, buffer, null, null, true);
+      // In MediaSourceEngine, appendBuffer() is async and Promise-based, but
+      // at the browser level, it's event-based.
+      // MediaSourceEngine waits for the 'updateend' event from the
+      // SourceBuffer, and uses that to resolve the appendBuffer Promise.
+      // Here, we must trigger the event on the fake/mock SourceBuffer before
+      // waiting on the appendBuffer Promise.
+      videoSourceBuffer.updateend();
+      await appendInit;
+
+      mediaSourceEngine.setCaptionParser(mockCaptionParser);
+      expect(mockTextEngine.storeAndAppendClosedCaptions).not.
+          toHaveBeenCalled();
+      // Parse and append the closed captions embedded in video stream.
+      const appendVideo = mediaSourceEngine.appendBuffer(
+          ContentType.VIDEO, buffer, 0, Infinity, true);
+      videoSourceBuffer.updateend();
+      await appendVideo;
+
+      expect(mockTextEngine.storeAndAppendClosedCaptions).toHaveBeenCalled();
+    });
+
+    it('appends closed caption data only when mux.js is available',
+        async () => {
+      const originalMuxjs = window.muxjs;
+      try {
+        window['muxjs'] = null;
+        const initObject = new Map();
+        initObject.set(ContentType.VIDEO, fakeVideoStream);
+        await mediaSourceEngine.init(initObject, false);
+
+        mediaSourceEngine.setUseEmbeddedText(false);
+        const appendBuffer = mediaSourceEngine.appendBuffer(
+            ContentType.VIDEO, buffer, null, null, true);
+        // In MediaSourceEngine, appendBuffer() is async and Promise-based, but
+        // at the browser level, it's event-based.
+        // MediaSourceEngine waits for the 'updateend' event from the
+        // SourceBuffer, and uses that to resolve the appendBuffer Promise.
+        // Here, we must trigger the event on the fake/mock SourceBuffer before
+        // waiting on the appendBuffer Promise.
+        videoSourceBuffer.updateend();
+        await appendBuffer;
+
+        expect(mediaSourceEngine.getCaptionParser()).toBeNull();
+      } finally {
+        window['muxjs'] = originalMuxjs;
+      }
+    });
   });
 
   describe('remove', function() {
@@ -1101,7 +1161,7 @@ describe('MediaSourceEngine', function() {
       mockTextEngine = jasmine.createSpyObj('TextEngine', [
         'initParser', 'destroy', 'appendBuffer', 'remove', 'setTimestampOffset',
         'setAppendWindow', 'bufferStart', 'bufferEnd', 'bufferedAheadOf',
-        'setDisplayer', 'appendCues',
+        'setDisplayer', 'appendCues', 'storeAndAppendClosedCaptions',
       ]);
 
       let resolve = Promise.resolve.bind(Promise);

test/media/streaming_engine_unit.js

@@ -627,7 +627,6 @@ describe('StreamingEngine', function() {
 
       streamingEngine.init();
 
-      // TODO: add another test case for loading the same text stream.
       runTest(function() {
         if (playheadTime == 20) {
           mediaSourceEngine.clear.calls.reset();
@@ -642,6 +641,27 @@ describe('StreamingEngine', function() {
         }
       });
     });
+
+    it('only clears MediaSourceEngine when it loads a different text stream',
+        function() {
+      setupVod();
+      mediaSourceEngine = new shaka.test.FakeMediaSourceEngine(segmentData);
+      createStreamingEngine();
+      playhead.getTime.and.returnValue(0);
+      onStartupComplete.and.callFake(function() { setupFakeGetTime(0); });
+      onChooseStreams.and.callFake(onChooseStreamsWithUnloadedText);
+
+      streamingEngine.init();
+
+      runTest(function() {
+        if (playheadTime == 20) {
+          mediaSourceEngine.clear.calls.reset();
+          mediaSourceEngine.init.calls.reset();
+          streamingEngine.loadNewTextStream(textStream1);
+          expect(mediaSourceEngine.clear).not.toHaveBeenCalledWith('text');
+        }
+      });
+    });
   });
 
   describe('unloadTextStream', function() {

test/test/util/simple_fakes.js

@@ -16,6 +16,7 @@
  */
 
 goog.provide('shaka.test.FakeAbrManager');
+goog.provide('shaka.test.FakeCaptionParser');
 goog.provide('shaka.test.FakeManifestParser');
 goog.provide('shaka.test.FakePlayhead');
 goog.provide('shaka.test.FakePlayheadObserver');
@@ -547,6 +548,28 @@ shaka.test.FakeTextTrack.prototype.addCue;
 shaka.test.FakeTextTrack.prototype.removeCue;
 
 
+/**
+ * Creates a mux.js closed caption parser.
+ *
+ * @constructor
+ * @struct
+ * @extends {muxjs.mp4.CaptionParser}
+ * @return {muxjs.mp4.CaptionParser}
+ */
+shaka.test.FakeCaptionParser = function() {
+  let parsedData = {
+      captionStreams: {},
+      captions: ['foo', 'bar'],
+  };
+  let captionParser = {
+    init: jasmine.createSpy('init'),
+    parse: jasmine.createSpy('parse'),
+    clearParsedCaptions: jasmine.createSpy('clearParsedCaptions'),
+  };
+  captionParser.parse.and.returnValue(parsedData);
+  return captionParser;
+};
+
 /**
  * Creates a text track.
  *

test/text/text_engine_unit.js

@@ -65,6 +65,20 @@ describe('TextEngine', function() {
       TextEngine.unregisterParser(dummyMimeType);
       expect(TextEngine.isTypeSupported(dummyMimeType)).toBe(false);
     });
+
+    it('reports support when it\'s closed captions and muxjs is available',
+          function() {
+        const closedCaptionsType =
+           shaka.util.MimeUtils.CLOSED_CAPTION_MIMETYPE;
+        const originalMuxjs = window.muxjs;
+        expect(TextEngine.isTypeSupported(closedCaptionsType)).toBe(true);
+        try {
+          window['muxjs'] = null;
+          expect(TextEngine.isTypeSupported(closedCaptionsType)).toBe(false);
+        } finally {
+          window['muxjs'] = originalMuxjs;
+        }
+    });
   });
 
   describe('appendBuffer', function() {