Support URI resolution for PDT between ExtInf and URI

src/main/java/com/blazemeter/jmeter/videostreaming/hls/Playlist.java

@@ -17,6 +17,7 @@
 import com.comcast.viper.hlsparserj.tags.master.Media;
 import com.comcast.viper.hlsparserj.tags.master.StreamInf;
 import com.comcast.viper.hlsparserj.tags.media.ByteRange;
+import com.comcast.viper.hlsparserj.tags.media.ExtInf;
 import com.comcast.viper.hlsparserj.tags.media.ExtMap;
 import com.comcast.viper.hlsparserj.tags.media.MediaSequence;
 import com.comcast.viper.hlsparserj.tags.media.PlaylistType;
@@ -136,11 +137,34 @@ public List<MediaSegment> getMediaSegments() {
     AtomicInteger sequenceNumber = new AtomicInteger(sequence);
 
     if (!hasByteRange()) {
-      return mediaPlaylist.getSegments().stream()
-          .map(s -> new MediaSegment(sequenceNumber.getAndIncrement(),
-              uri.resolve(s.getURI()), Duration.ofMillis(Math.round(s.getDuration() * 1000))))
-          .collect(Collectors.toList());
+      // hlsparserj assigns the segment URI to the tag line immediately above it. When
+      // #EXT-X-PROGRAM-DATE-TIME (or other tags) sit between #EXTINF and the media URI
+      // line, ExtInf.getURI() is null. Playlists with PDT before #EXTINF parse correctly.
+      List<ExtInf> segments = mediaPlaylist.getSegments();
+      List<String> fallbackUris = requiresSegmentUriFallback(segments)
+          ? extractSegmentUrisFromBody(body) : null;
+      List<MediaSegment> mediaSegments = new ArrayList<>(segments.size());
+      for (int i = 0; i < segments.size(); i++) {
+        ExtInf segment = segments.get(i);
+        String segmentUri = segment.getURI();
+        if (segmentUri == null && fallbackUris != null) {
+          if (i >= fallbackUris.size()) {
+            throw new IllegalStateException(
+                "Missing URI for segment at sequence " + sequenceNumber.get());
+          }
+          segmentUri = fallbackUris.get(i);
+        }
+        if (segmentUri == null) {
+          throw new IllegalStateException(
+              "Missing URI for segment at sequence " + sequenceNumber.get());
+        }
+        mediaSegments.add(new MediaSegment(sequenceNumber.getAndIncrement(),
+            uri.resolve(segmentUri), Duration.ofMillis(Math.round(segment.getDuration() * 1000))));
+      }
+      return mediaSegments;
     } else {
+      // Byte-range playlists rely on hlsparserj associating URIs with EXT-X-BYTERANGE.
+      // Same PDT-between-EXTINF-and-URI ordering is not covered here
       List<MediaSegment> mediaSegments = mediaPlaylist.getSegments().stream()
           .map(s -> new MediaSegment(sequenceNumber.getAndIncrement(),
               Duration.ofMillis(Math.round(s.getDuration() * 1000)))).collect(Collectors.toList());
@@ -156,6 +180,30 @@ public List<MediaSegment> getMediaSegments() {
     }
   }
 
+  static boolean requiresSegmentUriFallback(List<ExtInf> segments) {
+    return segments.stream().anyMatch(s -> s.getURI() == null);
+  }
+
+  static List<String> extractSegmentUrisFromBody(String body) {
+    List<String> uris = new ArrayList<>();
+    boolean afterExtInf = false;
+    for (String line : body.split("\n")) {
+      String trimmed = line.replace("\r", "").trim();
+      if (trimmed.isEmpty()) {
+        continue;
+      }
+      if (trimmed.startsWith("#EXTINF")) {
+        afterExtInf = true;
+      } else if (trimmed.startsWith("#")) {
+        continue;
+      } else if (afterExtInf) {
+        uris.add(trimmed);
+        afterExtInf = false;
+      }
+    }
+    return uris;
+  }
+
   public long getTargetDurationSeconds() {
     MediaPlaylist media = (MediaPlaylist) playlist;
     TargetDuration td = media.getTargetDuration();

src/test/java/com/blazemeter/jmeter/videostreaming/hls/HlsSamplerTest.java

@@ -38,6 +38,9 @@
 public class HlsSamplerTest extends VideoStreamingSamplerTest {
 
   private static final String SIMPLE_MEDIA_PLAYLIST_NAME = "simpleMediaPlaylist.m3u8";
+  private static final String MEDIA_PLAYLIST_PDT_BETWEEN_EXTINF_AND_URI_NAME =
+      "mediaPlaylistPdtBetweenExtInfAndUri.m3u8";
+  private static final double PDT_BETWEEN_EXTINF_AND_URI_SEGMENT_DURATION = 4.0;
   private static final URI MASTER_URI = URI.create(BASE_URI + "/master.m3u8");
   protected static final String MEDIA_TYPE_NAME = "media";
   protected static final double MEDIA_SEGMENT_DURATION = 5.0;
@@ -95,6 +98,18 @@ public void shouldDownloadSegmentWhenUriIsFromMediaPlaylist() throws Exception {
         buildMediaSegmentSampleResult(1));
   }
 
+  @Test
+  public void shouldDownloadSegmentWhenPdtIsBetweenExtInfAndUri() throws Exception {
+    String mediaPlaylist = getResource(MEDIA_PLAYLIST_PDT_BETWEEN_EXTINF_AND_URI_NAME);
+    setupUriSamplerPlaylist(MASTER_URI, mediaPlaylist);
+    setPlaySeconds(PDT_BETWEEN_EXTINF_AND_URI_SEGMENT_DURATION);
+    sampler.sample();
+    verifySampleResults(
+        buildBaseSampleResult(MEDIA_PLAYLIST_SAMPLE_NAME, MASTER_URI, mediaPlaylist),
+        buildMediaSegmentSampleResult(MASTER_URI.resolve("segment_001.ts"),
+            PDT_BETWEEN_EXTINF_AND_URI_SEGMENT_DURATION));
+  }
+
   private void setupUriSamplerPlaylist(URI uri, String... playlists) {
     HTTPSampleResult[] rest = new HTTPSampleResult[playlists.length - 1];
     for (int i = 1; i < playlists.length; i++) {
@@ -109,6 +124,12 @@ private HTTPSampleResult buildMediaSegmentSampleResult(int sequenceNumber) {
         MEDIA_SEGMENT_DURATION);
   }
 
+  private HTTPSampleResult buildMediaSegmentSampleResult(URI segmentUri, double segmentDuration) {
+    HTTPSampleResult result = buildSampleResult(segmentUri, SEGMENT_CONTENT_TYPE, "");
+    result.setSampleLabel(buildSegmentName(MEDIA_TYPE_NAME));
+    return addDurationHeader(result, segmentDuration);
+  }
+
   private HTTPSampleResult buildExpectedSegmentSampleResult(int sequenceNumber, String segmentType,
       double segmentDuration) {
     HTTPSampleResult result = buildBaseSegmentSampleResult(segmentType, sequenceNumber);

src/test/java/com/blazemeter/jmeter/videostreaming/hls/PlaylistTest.java

@@ -0,0 +1,80 @@
+package com.blazemeter.jmeter.videostreaming.hls;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import com.blazemeter.jmeter.videostreaming.core.MediaSegment;
+import com.blazemeter.jmeter.videostreaming.core.exception.PlaylistParsingException;
+import com.comcast.viper.hlsparserj.MediaPlaylist;
+import com.comcast.viper.hlsparserj.tags.media.ExtInf;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.util.List;
+import org.apache.commons.io.IOUtils;
+import org.junit.Test;
+
+public class PlaylistTest {
+
+  private static final URI MEDIA_PLAYLIST_URI = URI.create("http://test/media/variant.m3u8");
+
+  @Test
+  public void shouldResolveSegmentUrisWhenPdtIsBetweenExtInfAndUri() throws Exception {
+    Playlist playlist = parseResource("mediaPlaylistPdtBetweenExtInfAndUri.m3u8");
+    List<ExtInf> parsedSegments = ((MediaPlaylist) playlist.getPlaylist()).getSegments();
+
+    assertTrue(Playlist.requiresSegmentUriFallback(parsedSegments));
+
+    List<MediaSegment> segments = playlist.getMediaSegments();
+
+    assertEquals(3, segments.size());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("segment_001.ts"), segments.get(0).getUri());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("segment_002.ts"), segments.get(1).getUri());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("segment_003.ts"), segments.get(2).getUri());
+    assertEquals(17456L, segments.get(0).getSequenceNumber());
+    assertEquals(17457L, segments.get(1).getSequenceNumber());
+    assertEquals(17458L, segments.get(2).getSequenceNumber());
+  }
+
+  @Test
+  public void shouldKeepParserSegmentUrisWhenPdtIsBeforeExtInf() throws Exception {
+    Playlist playlist = parseResource("mediaPlaylistPdtBeforeExtInf.m3u8");
+    List<ExtInf> parsedSegments = ((MediaPlaylist) playlist.getPlaylist()).getSegments();
+
+    assertFalse(Playlist.requiresSegmentUriFallback(parsedSegments));
+
+    List<MediaSegment> segments = playlist.getMediaSegments();
+
+    assertEquals(2, segments.size());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("segment_001.ts"), segments.get(0).getUri());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("segment_002.ts"), segments.get(1).getUri());
+  }
+
+  @Test
+  public void shouldUseParserSegmentUrisWithoutFallbackForStandardPlaylist() throws Exception {
+    Playlist playlist = parseResource("simpleMediaPlaylist.m3u8");
+    List<ExtInf> parsedSegments = ((MediaPlaylist) playlist.getPlaylist()).getSegments();
+
+    assertFalse(Playlist.requiresSegmentUriFallback(parsedSegments));
+
+    List<MediaSegment> segments = playlist.getMediaSegments();
+
+    assertEquals(3, segments.size());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("/media/001.ts"), segments.get(0).getUri());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("/media/002.ts"), segments.get(1).getUri());
+    assertEquals(MEDIA_PLAYLIST_URI.resolve("/media/003.ts"), segments.get(2).getUri());
+  }
+
+  private static Playlist parseResource(String resourceName)
+      throws IOException, PlaylistParsingException {
+    String path = "com/blazemeter/jmeter/videostreaming/hls/" + resourceName;
+    try (InputStream in = PlaylistTest.class.getClassLoader().getResourceAsStream(path)) {
+      String body = IOUtils.toString(in, StandardCharsets.UTF_8);
+      return Playlist.fromUriAndBody(MEDIA_PLAYLIST_URI, body, Instant.now());
+    }
+  }
+
+}

src/test/resources/com/blazemeter/jmeter/videostreaming/hls/mediaPlaylistPdtBeforeExtInf.m3u8

@@ -0,0 +1,10 @@
+#EXTM3U
+#EXT-X-VERSION:6
+#EXT-X-TARGETDURATION:4
+#EXT-X-MEDIA-SEQUENCE:100
+#EXT-X-PROGRAM-DATE-TIME:2026-06-02T16:33:11.352+0200
+#EXTINF:4,
+segment_001.ts
+#EXT-X-PROGRAM-DATE-TIME:2026-06-02T16:33:15.352+0200
+#EXTINF:4,
+segment_002.ts

src/test/resources/com/blazemeter/jmeter/videostreaming/hls/mediaPlaylistPdtBetweenExtInfAndUri.m3u8

@@ -0,0 +1,14 @@
+#EXTM3U
+#EXT-X-VERSION:6
+#EXT-X-TARGETDURATION:4
+#EXT-X-MEDIA-SEQUENCE:17456
+#EXT-X-INDEPENDENT-SEGMENTS
+#EXTINF:4,
+#EXT-X-PROGRAM-DATE-TIME:2026-06-02T16:33:11.352+0200
+segment_001.ts
+#EXTINF:4,
+#EXT-X-PROGRAM-DATE-TIME:2026-06-02T16:33:15.352+0200
+segment_002.ts
+#EXTINF:4,
+#EXT-X-PROGRAM-DATE-TIME:2026-06-02T16:33:19.352+0200
+segment_003.ts