feat: add support for a frame-rate attribute (#159)

* feat: add support for a frame-rate attribute

* docs: fix typo in comment

Author: gjanblaszczyk

src/parseAttributes.js

@@ -1,3 +1,4 @@
+import { parseDivisionValue } from './utils/string';
 import { from } from './utils/list';
 import { parseDuration, parseDate } from './utils/time';
 
@@ -131,6 +132,18 @@ export const parsers = {
     return parseInt(value, 10);
   },
 
+  /**
+   * Specifies the frame rate of the representation
+   *
+   * @param {string} value
+   *        value of attribute as a string
+   * @return {number}
+   *         The parsed frame rate
+   */
+  frameRate(value) {
+    return parseDivisionValue(value);
+  },
+
   /**
    * Specifies the number of the first Media Segment in this Representation in the Period
    *

src/toM3u8.js

@@ -296,6 +296,10 @@ export const formatVideoPlaylist = ({
     segments
   };
 
+  if (attributes.frameRate) {
+    playlist.attributes['FRAME-RATE'] = attributes.frameRate;
+  }
+
   if (attributes.contentProtection) {
     playlist.contentProtection = attributes.contentProtection;
   }

src/utils/string.js

@@ -0,0 +1,10 @@
+/**
+ * Converts the provided string that may contain a division operation to a number.
+ *
+ * @param {string} value - the provided string value
+ *
+ * @return {number} the parsed string value
+ */
+export const parseDivisionValue = (value) => {
+  return parseFloat(value.split('/').reduce((prev, current) => prev / current));
+};

test/manifests/608-captions.js

@@ -36,6 +36,7 @@ export const parsedManifest = {
         'AUDIO': 'audio',
         'BANDWIDTH': 449000,
         'CODECS': 'avc1.420015',
+        'FRAME-RATE': 23.976,
         'NAME': '482',
         'PROGRAM-ID': 1,
         'RESOLUTION': {

test/manifests/708-captions.js

@@ -37,6 +37,7 @@ export const parsedManifest = {
         'AUDIO': 'audio',
         'BANDWIDTH': 449000,
         'CODECS': 'avc1.420015',
+        'FRAME-RATE': 23.976,
         'NAME': '482',
         'PROGRAM-ID': 1,
         'RESOLUTION': {

test/manifests/location.js

@@ -22,6 +22,7 @@ export const parsedManifest = {
         'AUDIO': 'audio',
         'BANDWIDTH': 449000,
         'CODECS': 'avc1.420015',
+        'FRAME-RATE': 23.976,
         'NAME': '482',
         'PROGRAM-ID': 1,
         'RESOLUTION': {

test/manifests/locations.js

@@ -23,6 +23,7 @@ export const parsedManifest = {
         'AUDIO': 'audio',
         'BANDWIDTH': 449000,
         'CODECS': 'avc1.420015',
+        'FRAME-RATE': 23.976,
         'NAME': '482',
         'PROGRAM-ID': 1,
         'RESOLUTION': {

test/manifests/maat_vtt_segmentTemplate.js

@@ -406,6 +406,7 @@ export const parsedManifest = {
         'NAME': '482',
         'AUDIO': 'audio',
         'SUBTITLES': 'subs',
+        'FRAME-RATE': 23.976,
         'RESOLUTION': {
           width: 482,
           height: 270
@@ -487,6 +488,7 @@ export const parsedManifest = {
         'NAME': '720',
         'AUDIO': 'audio',
         'SUBTITLES': 'subs',
+        'FRAME-RATE': 23.976,
         'RESOLUTION': {
           width: 720,
           height: 404

test/manifests/multiperiod-dynamic.js

@@ -613,16 +613,17 @@ export const parsedManifest = {
   playlists: [
     {
       attributes: {
-        'NAME': 'default_video2000_0_1280x720',
         'AUDIO': 'audio',
-        'SUBTITLES': 'subs',
+        'BANDWIDTH': 2008000,
+        'CODECS': 'avc1.4d001f',
+        'FRAME-RATE': 29.97,
+        'NAME': 'default_video2000_0_1280x720',
+        'PROGRAM-ID': 1,
         'RESOLUTION': {
-          width: 1280,
-          height: 720
+          height: 720,
+          width: 1280
         },
-        'CODECS': 'avc1.4d001f',
-        'BANDWIDTH': 2008000,
-        'PROGRAM-ID': 1
+        'SUBTITLES': 'subs'
       },
       uri: '',
       endList: false,
@@ -905,16 +906,17 @@ export const parsedManifest = {
     },
     {
       attributes: {
-        'NAME': 'default_video1200_1_960x540',
         'AUDIO': 'audio',
-        'SUBTITLES': 'subs',
+        'BANDWIDTH': 1195000,
+        'CODECS': 'avc1.4d001f',
+        'FRAME-RATE': 29.97,
+        'NAME': 'default_video1200_1_960x540',
+        'PROGRAM-ID': 1,
         'RESOLUTION': {
-          width: 960,
-          height: 540
+          height: 540,
+          width: 960
         },
-        'CODECS': 'avc1.4d001f',
-        'BANDWIDTH': 1195000,
-        'PROGRAM-ID': 1
+        'SUBTITLES': 'subs'
       },
       uri: '',
       endList: false,
@@ -1197,16 +1199,17 @@ export const parsedManifest = {
     },
     {
       attributes: {
-        'NAME': 'default_video900_1_640x360',
         'AUDIO': 'audio',
-        'SUBTITLES': 'subs',
+        'BANDWIDTH': 884000,
+        'CODECS': 'avc1.4d001e',
+        'FRAME-RATE': 29.97,
+        'NAME': 'default_video900_1_640x360',
+        'PROGRAM-ID': 1,
         'RESOLUTION': {
-          width: 640,
-          height: 360
+          height: 360,
+          width: 640
         },
-        'CODECS': 'avc1.4d001e',
-        'BANDWIDTH': 884000,
-        'PROGRAM-ID': 1
+        'SUBTITLES': 'subs'
       },
       uri: '',
       endList: false,

test/manifests/multiperiod-segment-list.js

@@ -15,6 +15,7 @@ export const parsedManifest = {
         'AUDIO': 'audio',
         'BANDWIDTH': 449000,
         'CODECS': 'avc1.420015',
+        'FRAME-RATE': 23.976,
         'NAME': '482',
         'PROGRAM-ID': 1,
         'RESOLUTION': {