fix(HLS): Avoid get basic info when the first segment is a gap (#6882)

shaka-project · Jun 21, 2024 · f217344 · f217344
1 parent 1c863c8
commit f217344
Showing 1 changed file with 24 additions and 16 deletions.
diff --git a/lib/hls/hls_parser.js b/lib/hls/hls_parser.js
@@ -2350,24 +2350,32 @@ shaka.hls.HlsParser = class {
           this.config_.hls.disableCodecGuessing) ||
           (this.needsClosedCaptionsDetection_ && type == ContentType.VIDEO &&
           !this.config_.hls.disableClosedCaptionsDetection)) {
-        this.needsClosedCaptionsDetection_ = false;
-
-        const basicInfo = await this.getMediaPlaylistBasicInfo_(
-            playlist, getUris, mediaVariables);
-
-        goog.asserts.assert(
-            type === basicInfo.type, 'Media types should match!');
-
-        if (basicInfo.closedCaptions.size && (!closedCaptions ||
-            closedCaptions.size != basicInfo.closedCaptions.size)) {
-          closedCaptions = basicInfo.closedCaptions;
-          closedCaptionsUpdated = true;
+        let canRequestBasicInfo = playlist.segments.length > 0;
+        if (canRequestBasicInfo) {
+          const segment = playlist.segments[0];
+          if (shaka.hls.Utils.getFirstTagWithName(segment.tags, 'EXT-X-GAP')) {
+            canRequestBasicInfo = false;
+          }
         }
+        if (canRequestBasicInfo) {
+          this.needsClosedCaptionsDetection_ = false;
+          const basicInfo = await this.getMediaPlaylistBasicInfo_(
+              playlist, getUris, mediaVariables);
+
+          goog.asserts.assert(
+              type === basicInfo.type, 'Media types should match!');
+
+          if (basicInfo.closedCaptions.size && (!closedCaptions ||
+              closedCaptions.size != basicInfo.closedCaptions.size)) {
+            closedCaptions = basicInfo.closedCaptions;
+            closedCaptionsUpdated = true;
+          }
 
-        if (!this.codecInfoInManifest_ &&
-            this.config_.hls.disableCodecGuessing) {
-          mimeType = basicInfo.mimeType;
-          codecs = basicInfo.codecs;
+          if (!this.codecInfoInManifest_ &&
+              this.config_.hls.disableCodecGuessing) {
+            mimeType = basicInfo.mimeType;
+            codecs = basicInfo.codecs;
+          }
         }
       }