feat: Improve parsing time in DASH and HLS (shaka-project#5261)

This PR improve the parsing time for DASH and HLS changing when the uris of the segments are constructed. Now the uris are constructed on demand.
theodab · Jun 7, 2023 · f1e35fd · f1e35fd
1 parent 5175e88
commit f1e35fd
Show file tree

Hide file tree

Showing 2 changed files with 28 additions and 10 deletions.
diff --git a/lib/dash/segment_list.js b/lib/dash/segment_list.js
@@ -223,9 +223,6 @@ shaka.dash.SegmentList = class {
     let prevEndTime = info.startTime;
     for (let i = 0; i < max; i++) {
       const segment = info.mediaSegments[i];
-      const mediaUri = ManifestParserUtils.resolveUris(
-          baseUris, [segment.mediaUri]);
-
       const startTime = prevEndTime;
       let endTime;
 
@@ -243,7 +240,13 @@ shaka.dash.SegmentList = class {
         endTime = startTime + periodDuration;
       }
 
-      const getUris = () => mediaUri;
+      let uris = null;
+      const getUris = () => {
+        if (uris == null) {
+          uris = ManifestParserUtils.resolveUris(baseUris, [segment.mediaUri]);
+        }
+        return uris;
+      };
       references.push(
           new shaka.media.SegmentReference(
               periodStart + startTime,

diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
@@ -2669,8 +2669,6 @@ shaka.hls.HlsParser = class {
       variables, absoluteMediaPlaylistUri, type, timestampOffset,
       hlsAes128Key) {
     const tags = hlsSegment.tags;
-    const absoluteSegmentUri = this.variableSubstitution_(
-        hlsSegment.absoluteUri, variables);
     const extinfTag =
         shaka.hls.Utils.getFirstTagWithName(tags, 'EXTINF');
 
@@ -2754,18 +2752,26 @@ shaka.hls.HlsParser = class {
         if (!pUri) {
           continue;
         }
-        const pAbsoluteUri = shaka.hls.Utils.constructAbsoluteUri(
-            absoluteMediaPlaylistUri, pUri);
 
         let partialStatus = shaka.media.SegmentReference.Status.AVAILABLE;
         if (item.getAttributeValue('GAP') == 'YES') {
           partialStatus = shaka.media.SegmentReference.Status.MISSING;
         }
 
+        let pAbsoluteUri = null;
+        const getPartialUris = () => {
+          if (pAbsoluteUri == null) {
+            goog.asserts.assert(pUri, 'Partial uri should be defined!');
+            pAbsoluteUri = shaka.hls.Utils.constructAbsoluteUri(
+                absoluteMediaPlaylistUri, pUri);
+          }
+          return [pAbsoluteUri];
+        };
+
         const partial = new shaka.media.SegmentReference(
             pStartTime,
             pEndTime,
-            () => [pAbsoluteUri],
+            getPartialUris,
             pStartByte,
             pEndByte,
             initSegmentReference,
@@ -2829,10 +2835,19 @@ shaka.hls.HlsParser = class {
       }
     }
 
+    let absoluteSegmentUri = null;
+    const getUris = () => {
+      if (absoluteSegmentUri == null) {
+        absoluteSegmentUri = this.variableSubstitution_(
+            hlsSegment.absoluteUri, variables);
+      }
+      return absoluteSegmentUri.length ? [absoluteSegmentUri] : [];
+    };
+
     return new shaka.media.SegmentReference(
         startTime,
         endTime,
-        () => absoluteSegmentUri.length ? [absoluteSegmentUri] : [],
+        getUris,
         startByte,
         endByte,
         initSegmentReference,