Lots of cleanup

2024-12-06 19:26:36 +01:00 · 2021-07-20 13:34:01 +05:30
parent bd189d4325
commit 355be0505f
13 changed files with 509 additions and 176 deletions
@@ -0,0 +1,190 @@
+// Based of https://github.com/GilgusMaximus/yt-dash-manifest-generator/blob/master/src/DashGenerator.js
+
+import xml from 'xml-js'
+
+const DashUtils = {
+  generate_dash_file_from_formats (VideoFormats, VideoLength) {
+    const generatedJSON = this.generate_xmljs_json_from_data(VideoFormats, VideoLength)
+    return xml.json2xml(generatedJSON)
+  },
+  generate_xmljs_json_from_data (VideoFormatArray, VideoLength) {
+    const convertJSON = {
+      declaration: {
+        attributes: {
+          version: '1.0',
+          encoding: 'utf-8'
+        }
+      },
+      elements: [
+        {
+          type: 'element',
+          name: 'MPD',
+          attributes: {
+            xmlns: 'urn:mpeg:dash:schema:mpd:2011',
+            profiles: 'urn:mpeg:dash:profile:full:2011',
+            minBufferTime: 'PT1.5S',
+            type: 'static',
+            mediaPresentationDuration: `PT${VideoLength}S`
+          },
+          elements: [
+            {
+              type: 'element',
+              name: 'Period',
+              elements: this.generate_adaptation_set(VideoFormatArray)
+            }
+          ]
+        }
+      ]
+    }
+    return convertJSON
+  },
+  generate_adaptation_set (VideoFormatArray) {
+    const adaptationSets = []
+    const mimeTypes = []
+    const mimeObjects = [[]]
+    // sort the formats by mime types
+    VideoFormatArray.forEach(videoFormat => {
+      // the dual formats should not be used
+      if (videoFormat.mimeType.indexOf('video') !== -1 && !videoFormat.videoOnly) {
+        return
+      }
+      // if these properties are not available, then we skip it because we cannot set these properties
+      // if (!(videoFormat.hasOwnProperty('initRange') && videoFormat.hasOwnProperty('indexRange'))) {
+      //   return
+      // }
+      const mimeType = videoFormat.mimeType
+      const mimeTypeIndex = mimeTypes.indexOf(mimeType)
+      if (mimeTypeIndex > -1) {
+        mimeObjects[mimeTypeIndex].push(videoFormat)
+      } else {
+        mimeTypes.push(mimeType)
+        mimeObjects.push([])
+        mimeObjects[mimeTypes.length - 1].push(videoFormat)
+      }
+    })
+    // for each MimeType generate a new Adaptation set with Representations as sub elements
+    for (let i = 0; i < mimeTypes.length; i++) {
+      let isVideoFormat = false
+      const adapSet = {
+        type: 'element',
+        name: 'AdaptationSet',
+        attributes: {
+          id: i,
+          mimeType: mimeTypes[i],
+          startWithSAP: '1',
+          subsegmentAlignment: 'true'
+        },
+        elements: []
+      }
+      if (!mimeTypes[i].includes('audio')) {
+        adapSet.attributes.scanType = 'progressive'
+        isVideoFormat = true
+      }
+      mimeObjects[i].forEach(format => {
+        if (isVideoFormat) {
+          adapSet.elements.push(this.generate_representation_video(format))
+        } else {
+          adapSet.elements.push(this.generate_representation_audio(format))
+        }
+      })
+      adaptationSets.push(adapSet)
+    }
+    return adaptationSets
+  },
+  generate_representation_audio (Format) {
+    const representation = {
+      type: 'element',
+      name: 'Representation',
+      attributes: {
+        id: Format.itag,
+        codecs: Format.codec,
+        bandwidth: Format.bitrate
+      },
+      elements: [
+        {
+          type: 'element',
+          name: 'AudioChannelConfiguration',
+          attributes: {
+            schemeIdUri: 'urn:mpeg:dash:23003:3:audio_channel_configuration:2011',
+            value: '2'
+          }
+        },
+        {
+          type: 'element',
+          name: 'BaseURL',
+          elements: [
+            {
+              type: 'text',
+              text: Format.url
+            }
+          ]
+        },
+        {
+          type: 'element',
+          name: 'SegmentBase',
+          attributes: {
+            indexRange: `${Format.indexStart}-${Format.indexEnd}`
+          },
+          elements: [
+            {
+              type: 'element',
+              name: 'Initialization',
+              attributes: {
+                range: `${Format.initStart}-${Format.initEnd}`
+              }
+            }
+          ]
+        }
+      ]
+    }
+    return representation
+  },
+  generate_representation_video (Format) {
+    const representation = {
+      type: 'element',
+      name: 'Representation',
+      attributes: {
+        id: Format.itag,
+        codecs: Format.codec,
+        bandwidth: Format.bitrate,
+        width: Format.width,
+        height: Format.height,
+        maxPlayoutRate: '1',
+        frameRate: Format.fps
+      },
+      elements: [
+        {
+          type: 'element',
+          name: 'BaseURL',
+          elements: [
+            {
+              type: 'text',
+              text: Format.url
+            }
+          ]
+        },
+        {
+          type: 'element',
+          name: 'SegmentBase',
+          attributes: {
+            indexRange: `${Format.indexStart}-${Format.indexEnd}`
+          },
+          elements: [
+            {
+              type: 'element',
+              name: 'Initialization',
+              attributes: {
+                range: `${Format.initStart}-${Format.initEnd}`
+              }
+            }
+          ]
+        }
+      ]
+    }
+    return representation
+  }
+}
+
+export {
+  DashUtils
+}