Add support for qualityRanking attribute in DASH manifests

src/parseAttributes.js

@@ -254,6 +254,21 @@ export const parsers = {
     return parseInt(value, 10);
   },
 
+  /**
+   * Specifies the quality ranking of the representation relative to others in the same
+   * adaptation set. This is inversely related to quality - higher values represent
+   * lower quality content (e.g., 1 = highest quality, 10 = lowest quality).
+   *
+   * @param {string} value
+   *        value of the attribute as a string
+   *
+   * @return {number}
+   *         The parsed qualityRanking
+   */
+  qualityranking(value) {
+    return parseInt(value, 10);
+  },
+
   /**
    * Default parser for all other attributes. Acts as a no-op and just returns the value
    * as a string

src/toM3u8.js

@@ -329,6 +329,12 @@ export const formatVideoPlaylist = ({
     playlist.attributes['FRAME-RATE'] = attributes.frameRate;
   }
 
+  // qualityRanking is inversely related to quality (higher value = lower quality)
+  // so SCORE is calculated as 1/qualityRanking (higher SCORE = higher quality)
+  if (attributes.qualityranking) {
+    playlist.attributes.SCORE = 1 / attributes.qualityranking;
+  }
+
   if (attributes.contentProtection) {
     playlist.contentProtection = attributes.contentProtection;
   }

test/index.test.js

@@ -21,6 +21,7 @@ import audioOnly from './manifests/audio-only.mpd';
 import multiperiodStartnumber from './manifests/multiperiod-startnumber.mpd';
 import multiperiodStartnumberRemovedPeriods from
   './manifests/multiperiod-startnumber-removed-periods.mpd';
+import qualityRanking from './manifests/quality-ranking.mpd';
 import {
   parsedManifest as maatVttSegmentTemplateManifest
 } from './manifests/maat_vtt_segmentTemplate.js';
@@ -71,6 +72,9 @@ import {
 import {
   parsedManifest as multiperiodStartnumberRemovedPeriodsManifest
 } from './manifests/multiperiod-startnumber-removed-periods.js';
+import {
+  parsedManifest as qualityRankingManifest
+} from './manifests/quality-ranking.js';
 
 QUnit.module('mpd-parser');
 
@@ -142,6 +146,10 @@ QUnit.test('has parse', function(assert) {
   name: 'multiperiod_startnumber',
   input: multiperiodStartnumber,
   expected: multiperiodStartnumberManifest
+}, {
+  name: 'quality-ranking',
+  input: qualityRanking,
+  expected: qualityRankingManifest
 }].forEach(({ name, input, expected }) => {
   QUnit.test(`${name} test manifest`, function(assert) {
     const actual = parse(input);

test/manifests/quality-ranking.js

@@ -0,0 +1,165 @@
+export const parsedManifest = {
+  allowCache: true,
+  discontinuityStarts: [],
+  segments: [],
+  timelineStarts: [{
+    start: 0,
+    timeline: 0
+  }],
+  endList: true,
+  mediaGroups: {
+    'AUDIO': {},
+    'VIDEO': {},
+    'CLOSED-CAPTIONS': {},
+    'SUBTITLES': {}
+  },
+  uri: '',
+  duration: 30,
+  playlists: [
+    {
+      attributes: {
+        'NAME': 'low',
+        'AUDIO': 'audio',
+        'SUBTITLES': 'subs',
+        'RESOLUTION': {
+          width: 640,
+          height: 360
+        },
+        'CODECS': 'avc1.4d401e',
+        'BANDWIDTH': 500000,
+        'PROGRAM-ID': 1,
+        'SCORE': 1
+      },
+      uri: '',
+      endList: true,
+      timeline: 0,
+      resolvedUri: 'http://example.com/video_low.mp4',
+      targetDuration: 30,
+      discontinuityStarts: [],
+      timelineStarts: [{
+        start: 0,
+        timeline: 0
+      }],
+      segments: [],
+      sidx: {
+        uri: 'http://example.com/video_low.mp4',
+        resolvedUri: 'http://example.com/video_low.mp4',
+        byterange: {
+          length: 201,
+          offset: 1000
+        },
+        map: {
+          uri: '',
+          resolvedUri: 'http://example.com/video_low.mp4',
+          byterange: {
+            length: 1000,
+            offset: 0
+          }
+        },
+        duration: 30,
+        timeline: 0,
+        presentationTime: 0,
+        number: 0
+      },
+      mediaSequence: 0,
+      discontinuitySequence: 0
+    },
+    {
+      attributes: {
+        'NAME': 'medium',
+        'AUDIO': 'audio',
+        'SUBTITLES': 'subs',
+        'RESOLUTION': {
+          width: 1280,
+          height: 720
+        },
+        'CODECS': 'avc1.4d401f',
+        'BANDWIDTH': 1000000,
+        'PROGRAM-ID': 1,
+        'SCORE': 0.2
+      },
+      uri: '',
+      endList: true,
+      timeline: 0,
+      resolvedUri: 'http://example.com/video_medium.mp4',
+      targetDuration: 30,
+      discontinuityStarts: [],
+      timelineStarts: [{
+        start: 0,
+        timeline: 0
+      }],
+      segments: [],
+      sidx: {
+        uri: 'http://example.com/video_medium.mp4',
+        resolvedUri: 'http://example.com/video_medium.mp4',
+        byterange: {
+          length: 201,
+          offset: 1000
+        },
+        map: {
+          uri: '',
+          resolvedUri: 'http://example.com/video_medium.mp4',
+          byterange: {
+            length: 1000,
+            offset: 0
+          }
+        },
+        duration: 30,
+        timeline: 0,
+        presentationTime: 0,
+        number: 0
+      },
+      mediaSequence: 0,
+      discontinuitySequence: 0
+    },
+    {
+      attributes: {
+        'NAME': 'high',
+        'AUDIO': 'audio',
+        'SUBTITLES': 'subs',
+        'RESOLUTION': {
+          width: 1920,
+          height: 1080
+        },
+        'CODECS': 'avc1.4d4028',
+        'BANDWIDTH': 2000000,
+        'PROGRAM-ID': 1,
+        'SCORE': 0.1
+      },
+      uri: '',
+      endList: true,
+      timeline: 0,
+      resolvedUri: 'http://example.com/video_high.mp4',
+      targetDuration: 30,
+      discontinuityStarts: [],
+      timelineStarts: [{
+        start: 0,
+        timeline: 0
+      }],
+      segments: [],
+      sidx: {
+        uri: 'http://example.com/video_high.mp4',
+        resolvedUri: 'http://example.com/video_high.mp4',
+        byterange: {
+          length: 201,
+          offset: 1000
+        },
+        map: {
+          uri: '',
+          resolvedUri: 'http://example.com/video_high.mp4',
+          byterange: {
+            length: 1000,
+            offset: 0
+          }
+        },
+        duration: 30,
+        timeline: 0,
+        presentationTime: 0,
+        number: 0
+      },
+      mediaSequence: 0,
+      discontinuitySequence: 0
+    }
+  ]
+};
+

test/manifests/quality-ranking.mpd

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="urn:mpeg:dash:schema:mpd:2011 DASH-MPD.xsd" profiles="urn:mpeg:dash:profile:isoff-on-demand:2011" minBufferTime="PT2S" type="static" mediaPresentationDuration="PT30S">
+  <Period id="0">
+    <AdaptationSet id="0" contentType="video" subsegmentAlignment="true">
+      <Representation id="low" bandwidth="500000" codecs="avc1.4d401e" mimeType="video/mp4" width="640" height="360" qualityranking="1">
+        <BaseURL>http://example.com/video_low.mp4</BaseURL>
+        <SegmentBase indexRange="1000-1200" timescale="30000">
+          <Initialization range="0-999"/>
+        </SegmentBase>
+      </Representation>
+      <Representation id="medium" bandwidth="1000000" codecs="avc1.4d401f" mimeType="video/mp4" width="1280" height="720" qualityranking="5">
+        <BaseURL>http://example.com/video_medium.mp4</BaseURL>
+        <SegmentBase indexRange="1000-1200" timescale="30000">
+          <Initialization range="0-999"/>
+        </SegmentBase>
+      </Representation>
+      <Representation id="high" bandwidth="2000000" codecs="avc1.4d4028" mimeType="video/mp4" width="1920" height="1080" qualityranking="10">
+        <BaseURL>http://example.com/video_high.mp4</BaseURL>
+        <SegmentBase indexRange="1000-1200" timescale="30000">
+          <Initialization range="0-999"/>
+        </SegmentBase>
+      </Representation>
+    </AdaptationSet>
+  </Period>
+</MPD>
+

test/parseAttributes.test.js

@@ -19,3 +19,29 @@ QUnit.test('empty', function(assert) {
 
   assert.deepEqual(parseAttributes(el), {});
 });
+
+QUnit.test('parses qualityRanking as integer', function(assert) {
+  const el = document.createElement('Representation');
+
+  el.setAttribute('qualityRanking', '5');
+
+  assert.deepEqual(parseAttributes(el), { qualityranking: 5 });
+});
+
+QUnit.test('parses multiple attributes including qualityRanking', function(assert) {
+  const el = document.createElement('Representation');
+
+  el.setAttribute('id', 'test-id');
+  el.setAttribute('bandwidth', '1000000');
+  el.setAttribute('qualityRanking', '10');
+  el.setAttribute('width', '1920');
+  el.setAttribute('height', '1080');
+
+  assert.deepEqual(parseAttributes(el), {
+    id: 'test-id',
+    bandwidth: 1000000,
+    qualityranking: 10,
+    width: 1920,
+    height: 1080
+  });
+});