feat(DASH): Parse and use target latency

shaka-project · May 28, 2024 · 0cc9f1b · 0cc9f1b
2 parents e7040dc + c541515
commit 0cc9f1b
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Showing 6 changed files with 80 additions and 14 deletions.
diff --git a/demo/common/assets.js b/demo/common/assets.js
@@ -1492,7 +1492,13 @@ shakaAssets.testAssets = [
       .addFeature(shakaAssets.Feature.DASH)
       .addFeature(shakaAssets.Feature.HIGH_DEFINITION)
       .addFeature(shakaAssets.Feature.MP4)
-      .addFeature(shakaAssets.Feature.LIVE),
+      .addFeature(shakaAssets.Feature.LIVE)
+      .addFeature(shakaAssets.Feature.LOW_LATENCY)
+      .setExtraConfig({
+        streaming: {
+          lowLatencyMode: true,
+        },
+      }),
   // }}}
 
   // EZDRM assets {{{

diff --git a/externs/shaka/player.js b/externs/shaka/player.js
@@ -1439,7 +1439,7 @@ shaka.extern.ManifestConfiguration;
  * @property {number} liveSyncMinPlaybackRate
  *   Minimum playback rate used for latency chasing. It is recommended to use a
  *   value between 0 and 1. Effective only if liveSync is true. Defaults to
- *   <code>1</code>.
+ *   <code>0.95</code>.
  * @property {boolean} liveSyncPanicMode
  *   If <code>true</code>, panic mode for live sync is enabled. When enabled,
  *   will set the playback rate to the <code>liveSyncMinPlaybackRate</code>

diff --git a/lib/player.js b/lib/player.js
@@ -6219,12 +6219,12 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       // liveSync configuration is not set.
       if (this.manifest_ && this.manifest_.serviceDescription) {
         liveSyncMaxLatency = this.config_.streaming.liveSyncMaxLatency;
-        if (this.manifest_.serviceDescription.maxLatency != null) {
-          liveSyncMaxLatency = this.manifest_.serviceDescription.maxLatency;
-        } else if (this.manifest_.serviceDescription.targetLatency != null) {
+        if (this.manifest_.serviceDescription.targetLatency != null) {
           liveSyncMaxLatency =
               this.manifest_.serviceDescription.targetLatency +
               this.config_.streaming.liveSyncTargetLatencyTolerance;
+        } else if (this.manifest_.serviceDescription.maxLatency != null) {
+          liveSyncMaxLatency = this.manifest_.serviceDescription.maxLatency;
         }
         liveSyncPlaybackRate =
           this.manifest_.serviceDescription.maxPlaybackRate ||
@@ -6242,12 +6242,12 @@ shaka.Player = class extends shaka.util.FakeEventTarget {
       // liveSync configuration is not set.
       if (this.manifest_ && this.manifest_.serviceDescription) {
         liveSyncMinLatency = this.config_.streaming.liveSyncMinLatency;
-        if (this.manifest_.serviceDescription.minLatency != null) {
-          liveSyncMinLatency = this.manifest_.serviceDescription.minLatency;
-        } else if (this.manifest_.serviceDescription.targetLatency != null) {
+        if (this.manifest_.serviceDescription.targetLatency != null) {
           liveSyncMinLatency =
               this.manifest_.serviceDescription.targetLatency -
               this.config_.streaming.liveSyncTargetLatencyTolerance;
+        } else if (this.manifest_.serviceDescription.minLatency != null) {
+          liveSyncMinLatency = this.manifest_.serviceDescription.minLatency;
         }
         liveSyncMinPlaybackRate =
           this.manifest_.serviceDescription.minPlaybackRate ||

diff --git a/lib/util/platform.js b/lib/util/platform.js
@@ -108,6 +108,24 @@ shaka.util.Platform = class {
     return shaka.util.Platform.userAgentContains_('Tizen');
   }
 
+  /**
+   * Check if the current platform is a Tizen 6 TV.
+   *
+   * @return {boolean}
+   */
+  static isTizen6() {
+    return shaka.util.Platform.userAgentContains_('Tizen 6');
+  }
+
+  /**
+   * Check if the current platform is a Tizen 5 TV.
+   *
+   * @return {boolean}
+   */
+  static isTizen5() {
+    return shaka.util.Platform.userAgentContains_('Tizen 5');
+  }
+
   /**
    * Check if the current platform is a Tizen 4 TV.
    *
@@ -588,8 +606,8 @@ shaka.util.Platform = class {
    */
   static supportsSmoothCodecSwitching() {
     const Platform = shaka.util.Platform;
-    if (Platform.isTizen2() || Platform.isTizen3() ||
-        Platform.isTizen4() || Platform.isWebOS3() ||
+    if (Platform.isTizen2() || Platform.isTizen3() || Platform.isTizen4() ||
+        Platform.isTizen5() || Platform.isTizen6() || Platform.isWebOS3() ||
         Platform.isWebOS4() || Platform.isWebOS5()) {
       return false;
     }

diff --git a/lib/util/player_configuration.js b/lib/util/player_configuration.js
@@ -242,7 +242,7 @@ shaka.util.PlayerConfiguration = class {
       liveSyncMaxLatency: 1,
       liveSyncPlaybackRate: 1.1,
       liveSyncMinLatency: 0,
-      liveSyncMinPlaybackRate: 1,
+      liveSyncMinPlaybackRate: 0.95,
       liveSyncPanicMode: false,
       liveSyncPanicThreshold: 60,
       allowMediaSourceRecoveries: true,

diff --git a/test/util/platform_unit.js b/test/util/platform_unit.js
@@ -7,19 +7,57 @@
 describe('Platform', () => {
   const originalUserAgent = navigator.userAgent;
 
+  /* eslint-disable max-len */
+  // See: https://developer.samsung.com/smarttv/develop/guides/fundamentals/retrieving-platform-information.html
+  const tizen50 = 'Mozilla/5.0 (SMART-TV; LINUX; Tizen 5.0) AppleWebKit/537.36 (KHTML, like Gecko) Version/5.0 TV Safari/537.36';
+  const tizen55 = 'Mozilla/5.0 (SMART-TV; LINUX; Tizen 5.5) AppleWebKit/537.36 (KHTML, like Gecko) 69.0.3497.106.1/5.5 TV Safari/537.36';
+  const tizen60 = 'Mozilla/5.0 (SMART-TV; LINUX; Tizen 6.0) AppleWebKit/537.36 (KHTML, like Gecko) 76.0.3809.146/6.0 TV Safari/537.36';
+  const tizen65 = 'Mozilla/5.0 (SMART-TV; LINUX; Tizen 6.5) AppleWebKit/537.36 (KHTML, like Gecko) 85.0.4183.93/6.5 TV Safari/537.36';
+  const tizen70 = 'Mozilla/5.0 (SMART-TV; LINUX; Tizen 7.0) AppleWebKit/537.36 (KHTML, like Gecko) 94.0.4606.31/7.0 TV Safari/537.36';
+
   // See: https://webostv.developer.lge.com/develop/specifications/web-api-and-web-engine#useragent-string
-  // eslint-disable-next-line max-len
   const webOs3 = 'Mozilla/5.0 (Web0S; Linux/SmartTV) AppleWebKit/537.36 (KHTML, like Gecko) QtWebEngine/5.2.1 Chrome/38.0.2125.122 Safari/537.36 WebAppManager';
-  // eslint-disable-next-line max-len
   const webOs4 = 'Mozilla/5.0 (Web0S; Linux/SmartTV) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.34 Safari/537.36 WebAppManager';
-  // eslint-disable-next-line max-len
   const webOs5 = 'Mozilla/5.0 (Web0S; Linux/SmartTV) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36 WebAppManager';
+  /* eslint-enable max-len */
 
   afterEach(() => {
     setUserAgent(originalUserAgent);
   });
 
+  it('checks is Tizen 5', () => {
+    setUserAgent(webOs3);
+    expect(shaka.util.Platform.isTizen5()).toBe(false);
+    setUserAgent(tizen50);
+    expect(shaka.util.Platform.isTizen5()).toBe(true);
+    setUserAgent(tizen55);
+    expect(shaka.util.Platform.isTizen5()).toBe(true);
+    setUserAgent(tizen60);
+    expect(shaka.util.Platform.isTizen5()).toBe(false);
+    setUserAgent(tizen65);
+    expect(shaka.util.Platform.isTizen5()).toBe(false);
+    setUserAgent(tizen70);
+    expect(shaka.util.Platform.isTizen5()).toBe(false);
+  });
+
+  it('checks is Tizen 6', () => {
+    setUserAgent(webOs3);
+    expect(shaka.util.Platform.isTizen6()).toBe(false);
+    setUserAgent(tizen50);
+    expect(shaka.util.Platform.isTizen6()).toBe(false);
+    setUserAgent(tizen55);
+    expect(shaka.util.Platform.isTizen6()).toBe(false);
+    setUserAgent(tizen60);
+    expect(shaka.util.Platform.isTizen6()).toBe(true);
+    setUserAgent(tizen65);
+    expect(shaka.util.Platform.isTizen6()).toBe(true);
+    setUserAgent(tizen70);
+    expect(shaka.util.Platform.isTizen6()).toBe(false);
+  });
+
   it('checks is webOS 3', () => {
+    setUserAgent(tizen50);
+    expect(shaka.util.Platform.isWebOS3()).toBe(false);
     setUserAgent(webOs3);
     expect(shaka.util.Platform.isWebOS3()).toBe(true);
     setUserAgent(webOs4);
@@ -29,6 +67,8 @@ describe('Platform', () => {
   });
 
   it('checks is webOS 4', () => {
+    setUserAgent(tizen50);
+    expect(shaka.util.Platform.isWebOS4()).toBe(false);
     setUserAgent(webOs3);
     expect(shaka.util.Platform.isWebOS4()).toBe(false);
     setUserAgent(webOs4);
@@ -38,6 +78,8 @@ describe('Platform', () => {
   });
 
   it('checks is webOS 5', () => {
+    setUserAgent(tizen50);
+    expect(shaka.util.Platform.isWebOS5()).toBe(false);
     setUserAgent(webOs3);
     expect(shaka.util.Platform.isWebOS5()).toBe(false);
     setUserAgent(webOs4);