feat: Update usage of minBufferTime according to the DASH spec

Related to #7602 (comment)

docs/tutorials/faq.md

@@ -191,19 +191,6 @@ the ad blocker in compiled mode as well.
 
 <hr>
 
-**Q:** Why does some DASH content take a long time to start playback?
-
-**A:** Shaka Player honors the `minBufferTime` field in DASH.  If this field is
-set to a large value, Shaka Player will buffer that much content before
-beginning playback.  To override this behavior and ignore the `minBufferTime`
-field, we offer the following configuration:
-
-```js
-player.configure('manifest.dash.ignoreMinBufferTime', true);
-```
-
-<hr>
-
 **Q:** My HLS stream is failing on Chrome, with a chunk demuxer append failed
 error.
 

docs/tutorials/manifest-parser.md

@@ -256,7 +256,6 @@ MyManifestParser.prototype.loadManifest_ = function(data) {
 
   return {
     presentationTimeline: timeline,
-    minBufferTime: 5,  // seconds
     offlineSessionIds: [],
     variants: [
       this.loadVariant_(true, true),

docs/tutorials/network-and-buffering-config.md

@@ -70,13 +70,6 @@ content will be removed from the start of the buffer to save memory.
 This is a minimum; if the stream's max segment size is longer than the
 'bufferBehind', then that will be used instead.
 
-
-*NOTES:*
- - *`rebufferingGoal` should always be less than `bufferingGoal`.*
- - *A DASH manifest's `minBufferTime`, if greater, overrides `rebufferingGoal`.*
- - *You can ignore `minBufferTime` by setting the
-   `manifest.dash.ignoreMinBufferTime` configuration to true.*
-
 All of these settings should be customized for your application.  The default
 values are very conservative.
 

externs/shaka/manifest.js

@@ -17,7 +17,6 @@
  *   textStreams: !Array.<shaka.extern.Stream>,
  *   imageStreams: !Array.<shaka.extern.Stream>,
  *   offlineSessionIds: !Array.<string>,
- *   minBufferTime: number,
  *   sequenceMode: boolean,
  *   ignoreManifestTimestampsInSegmentsMode: boolean,
  *   type: string,
@@ -76,11 +75,6 @@
  * @property {!Array.<string>} offlineSessionIds
  *   <i>Defaults to [].</i> <br>
  *   An array of EME sessions to load for offline playback.
- * @property {number} minBufferTime
- *   <i>Defaults to 0.</i> <br>
- *   The minimum number of seconds of content that must be buffered before
- *   playback can begin.  Can be overridden by a higher value from the Player
- *   configuration.
  * @property {boolean} sequenceMode
  *   If true, we will append the media segments using sequence mode; that is to
  *   say, ignoring any timestamps inside the media files.

externs/shaka/player.js

@@ -1104,8 +1104,7 @@ shaka.extern.xml.Node;
  *   Defaults to <code>false</code>.
  * @property {boolean} ignoreMinBufferTime
  *   If true will cause DASH parser to ignore <code>minBufferTime</code> from
- *   manifest. It allows player config to take precedence over manifest for
- *   <code>rebufferingGoal</code>.
+ *   manifest.
  *   <br>
  *   Defaults to <code>false</code>.
  * @property {boolean} autoCorrectDrift

lib/dash/dash_parser.js

@@ -799,10 +799,7 @@ shaka.dash.DashParser = class {
 
     await contentSteeringPromise;
 
-    // Set minBufferTime to 0 for low-latency DASH live stream to achieve the
-    // best latency
     if (this.lowLatencyMode_) {
-      minBufferTime = 0;
       const presentationDelay = suggestedPresentationDelay != null ?
           suggestedPresentationDelay : this.config_.defaultPresentationDelay;
       presentationTimeline.setDelay(presentationDelay);
@@ -818,7 +815,6 @@ shaka.dash.DashParser = class {
         textStreams: this.periodCombiner_.getTextStreams(),
         imageStreams: this.periodCombiner_.getImageStreams(),
         offlineSessionIds: [],
-        minBufferTime: minBufferTime || 0,
         sequenceMode: this.config_.dash.sequenceMode,
         ignoreManifestTimestampsInSegmentsMode: false,
         type: shaka.media.ManifestParser.DASH,

lib/hls/hls_parser.js

@@ -1002,7 +1002,6 @@ shaka.hls.HlsParser = class {
       textStreams,
       imageStreams,
       offlineSessionIds: [],
-      minBufferTime: 0,
       sequenceMode: this.config_.hls.sequenceMode,
       ignoreManifestTimestampsInSegmentsMode:
         this.config_.hls.ignoreManifestTimestampsInSegmentsMode,

lib/media/playhead.js

@@ -231,9 +231,6 @@ shaka.media.MediaSourcePlayhead = class {
     /** @private {shaka.media.PresentationTimeline} */
     this.timeline_ = manifest.presentationTimeline;
 
-    /** @private {number} */
-    this.minBufferTime_ = manifest.minBufferTime || 0;
-
     /** @private {?shaka.extern.StreamingConfiguration} */
     this.config_ = config;
 
@@ -482,10 +479,7 @@ shaka.media.MediaSourcePlayhead = class {
     const isBuffered = (playheadTime) => shaka.media.TimeRangesUtils.isBuffered(
         this.mediaElement_.buffered, playheadTime);
 
-    const rebufferingGoal = Math.max(
-        this.minBufferTime_,
-        this.config_.rebufferingGoal);
-
+    const rebufferingGoal = this.config_.rebufferingGoal;
     const safeSeekOffset = this.config_.safeSeekOffset;
 
     let start = this.timeline_.getSeekRangeStart();

lib/media/streaming_engine.js

@@ -779,9 +779,7 @@ shaka.media.StreamingEngine = class {
     // If the new segment can be finished in time without risking a buffer
     // underflow, we should abort the old one and switch.
     const bufferedAhead = (bufferEnd || 0) - presentationTime;
-    const safetyBuffer = Math.max(
-        this.manifest_.minBufferTime || 0,
-        this.config_.rebufferingGoal);
+    const safetyBuffer = this.config_.rebufferingGoal;
     const safeBufferedAhead = bufferedAhead - safetyBuffer;
     if (timeToFetchNewSegment < safeBufferedAhead) {
       return true;
@@ -1366,9 +1364,7 @@ shaka.media.StreamingEngine = class {
         'bufferedAhead=' + bufferedAhead);
 
     const unscaledBufferingGoal = Math.max(
-        this.manifest_.minBufferTime || 0,
-        this.config_.rebufferingGoal,
-        this.config_.bufferingGoal);
+        this.config_.rebufferingGoal, this.config_.bufferingGoal);
 
     const scaledBufferingGoal = Math.max(1,
         unscaledBufferingGoal * this.bufferingScale_);

lib/mss/mss_parser.js

@@ -431,7 +431,6 @@ shaka.mss.MssParser = class {
         textStreams: context.textStreams,
         imageStreams: [],
         offlineSessionIds: [],
-        minBufferTime: 0,
         sequenceMode: this.config_.mss.sequenceMode,
         ignoreManifestTimestampsInSegmentsMode: false,
         type: shaka.media.ManifestParser.MSS,

lib/offline/manifest_converter.js

@@ -84,7 +84,6 @@ shaka.offline.ManifestConverter = class {
 
     return {
       presentationTimeline: timeline,
-      minBufferTime: 2,
       offlineSessionIds: manifestDB.sessionIds,
       variants: Array.from(variants.values()),
       textStreams: textStreams,

lib/player.js

@@ -2638,13 +2638,8 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       this.playheadObservers_ =
           this.createPlayheadObserversForMSE_(startTime);
 
-      // We need to start the buffer management code near the end because it
-      // will set the initial buffering state and that depends on other
-      // components being initialized.
-      const rebufferThreshold = Math.max(
-          this.manifest_.minBufferTime,
-          this.config_.streaming.rebufferingGoal);
-      this.startBufferManagement_(mediaElement, rebufferThreshold);
+      this.startBufferManagement_(
+          mediaElement, this.config_.streaming.rebufferingGoal);
     };
 
     if (!this.config_.streaming.startAtSegmentBoundary) {
@@ -4187,12 +4182,7 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       this.onAbrStatusChanged_();
     }
     if (this.bufferObserver_) {
-      let rebufferThreshold = this.config_.streaming.rebufferingGoal;
-      if (this.manifest_) {
-        rebufferThreshold =
-            Math.max(rebufferThreshold, this.manifest_.minBufferTime);
-      }
-      this.updateBufferingSettings_(rebufferThreshold);
+      this.updateBufferingSettings_(this.config_.streaming.rebufferingGoal);
     }
 
     if (this.manifest_) {

test/dash/dash_parser_manifest_unit.js

@@ -170,7 +170,6 @@ describe('DashParser Manifest', () => {
           manifest.sequenceMode = true;
           manifest.type = shaka.media.ManifestParser.DASH;
           manifest.anyTimeline();
-          manifest.minBufferTime = 75;
           manifest.addPartialVariant((variant) => {
             variant.language = 'en';
             variant.bandwidth = 200;
@@ -256,7 +255,6 @@ describe('DashParser Manifest', () => {
           manifest.sequenceMode = false;
           manifest.type = shaka.media.ManifestParser.DASH;
           manifest.anyTimeline();
-          manifest.minBufferTime = 75;
           manifest.addPartialVariant((variant) => {
             variant.language = 'en';
             variant.bandwidth = 200;
@@ -1759,56 +1757,6 @@ describe('DashParser Manifest', () => {
     expect(stream).toBeUndefined();
   });
 
-  it('override manifest value if ignoreMinBufferTime is true', async () => {
-    const manifestText = [
-      '<MPD minBufferTime="PT75S">',
-      '  <Period id="1" duration="PT30S">',
-      '    <AdaptationSet id="1" mimeType="video/mp4">',
-      '      <Representation id="video-sd" width="640" height="480">',
-      '        <BaseURL>v-sd.mp4</BaseURL>',
-      '        <SegmentBase indexRange="100-200" />',
-      '      </Representation>',
-      '    </AdaptationSet>',
-      '  </Period>',
-      '</MPD>',
-    ].join('\n');
-
-    fakeNetEngine.setResponseText('dummy://foo', manifestText);
-    const config = shaka.util.PlayerConfiguration.createDefault().manifest;
-    config.dash.ignoreMinBufferTime = true;
-    parser.configure(config);
-
-    /** @type {shaka.extern.Manifest} */
-    const manifest = await parser.start('dummy://foo', playerInterface);
-    const minBufferTime = manifest.minBufferTime;
-    expect(minBufferTime).toBe(0);
-  });
-
-  it('get manifest value if ignoreMinBufferTime is false', async () => {
-    const manifestText = [
-      '<MPD minBufferTime="PT75S">',
-      '  <Period id="1" duration="PT30S">',
-      '    <AdaptationSet id="1" mimeType="video/mp4">',
-      '      <Representation id="video-sd" width="640" height="480">',
-      '        <BaseURL>v-sd.mp4</BaseURL>',
-      '        <SegmentBase indexRange="100-200" />',
-      '      </Representation>',
-      '    </AdaptationSet>',
-      '  </Period>',
-      '</MPD>',
-    ].join('\n');
-
-    fakeNetEngine.setResponseText('dummy://foo', manifestText);
-    const config = shaka.util.PlayerConfiguration.createDefault().manifest;
-    config.dash.ignoreMinBufferTime = false;
-    parser.configure(config);
-
-    /** @type {shaka.extern.Manifest} */
-    const manifest = await parser.start('dummy://foo', playerInterface);
-    const minBufferTime = manifest.minBufferTime;
-    expect(minBufferTime).toBe(75);
-  });
-
   it('honors the ignoreMaxSegmentDuration config', async () => {
     const manifestText = [
       '<MPD maxSegmentDuration="PT5S">',
@@ -1944,7 +1892,7 @@ describe('DashParser Manifest', () => {
     const manifest = await parser.start('dummy://foo', playerInterface);
     const presentationTimeline = manifest.presentationTimeline;
     const presentationDelay = presentationTimeline.getDelay();
-    expect(presentationDelay).toBe(1.5*manifest.minBufferTime);
+    expect(presentationDelay).toBe(3);
   });
 
   it('Honors the ignoreEmptyAdaptationSet config', async () => {

test/media/playhead_unit.js

@@ -131,7 +131,6 @@ describe('Playhead', () => {
       textStreams: [],
       imageStreams: [],
       presentationTimeline: timeline,
-      minBufferTime: 10,
       offlineSessionIds: [],
       sequenceMode: false,
       ignoreManifestTimestampsInSegmentsMode: false,

test/media/streaming_engine_integration.js

@@ -598,7 +598,6 @@ describe('StreamingEngine', () => {
       return {
         presentationTimeline: timeline,
         offlineSessionIds: [],
-        minBufferTime: 2,
         textStreams: [],
         imageStreams: [],
         sequenceMode: false,

test/media/streaming_engine_unit.js

@@ -2641,8 +2641,6 @@ describe('StreamingEngine', () => {
     beforeEach(() => {
       setupVod();
 
-      manifest.minBufferTime = 1;
-
       config = shaka.util.PlayerConfiguration.createDefault().streaming;
       config.rebufferingGoal = 1;
       config.bufferingGoal = 1;
@@ -2752,8 +2750,6 @@ describe('StreamingEngine', () => {
     it('does not fail immediately', async () => {
       setupVod();
 
-      manifest.minBufferTime = 1;
-
       // Create StreamingEngine.
       const config = shaka.util.PlayerConfiguration.createDefault().streaming;
       config.rebufferingGoal = 1;
@@ -2816,8 +2812,6 @@ describe('StreamingEngine', () => {
     it('fails after multiple QuotaExceededError', async () => {
       setupVod();
 
-      manifest.minBufferTime = 1;
-
       // Create StreamingEngine.
       const config = shaka.util.PlayerConfiguration.createDefault().streaming;
       config.rebufferingGoal = 1;

test/offline/storage_compatibility_unit.js

@@ -279,7 +279,6 @@ filterDescribe('Storage Compatibility', offlineSupported, () => {
 
       const expected = shaka.test.ManifestGenerator.generate((manifest) => {
         manifest.anyTimeline();
-        manifest.minBufferTime = 2;
 
         manifest.addPartialVariant((variant) => {
           variant.addPartialStream(ContentType.VIDEO, (stream) => {

test/test/util/manifest_generator.js

@@ -93,8 +93,6 @@ shaka.test.ManifestGenerator.Manifest = class {
     this.presentationTimeline = timeline;
     /** @type {!Array.<string>} */
     this.offlineSessionIds = [];
-    /** @type {number} */
-    this.minBufferTime = 0;
     /** @type {boolean} */
     this.sequenceMode = false;
     /** @type {boolean} */

test/test/util/streaming_engine_util.js

@@ -329,7 +329,6 @@ shaka.test.StreamingEngineUtil = class {
     /** @type {shaka.extern.Manifest} */
     const manifest = {
       presentationTimeline,
-      minBufferTime: 2,
       offlineSessionIds: [],
       variants: [],
       textStreams: [],