fix: need to take into account when audio and video segment may differ

Eyevinn · Aug 8, 2023 · f6d03cf · f6d03cf
1 parent 3ffa3dc
commit f6d03cf
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Showing 3 changed files with 35 additions and 8 deletions.
diff --git a/index.js b/index.js
@@ -8,6 +8,7 @@ class HLSTruncateVod {
     this.playlists = {};
     this.duration = duration;
     this.durationAudio = 0;
+    this.startVideoOffset = 0;
     this.bandwiths = [];
     this.audioSegments = {};
     if (options && options.offset) {
@@ -155,11 +156,13 @@ class HLSTruncateVod {
         if (this.startOffset) {
           let accStartOffset = 0;
           m3u.items.PlaylistItem.map((item => {
-            if (accStartOffset <= this.startOffset) {
+            if (accStartOffset + item.get('duration') <= this.startOffset) {
               accStartOffset += item.get('duration');
               startPos++;
             }
           }));
+
+          this.startVideoOffset = this.startVideoOffset === 0 ? accStartOffset : this.startVideoOffset;
         }
 
         m3u.items.PlaylistItem.slice(startPos).map((item => {
@@ -214,11 +217,14 @@ class HLSTruncateVod {
         if (this.startOffset) {
           let accStartOffset = 0;
           m3u.items.PlaylistItem.map((item => {
-            if (accStartOffset <= this.startOffset) {
+            if (accStartOffset + item.get('duration') <= this.startOffset) {
               accStartOffset += item.get('duration');
               startPos++;
             }
           }));
+          if ((accStartOffset > this.startVideoOffset) && startPos > 1) {
+            startPos--;
+          }
         }
 
         m3u.items.PlaylistItem.slice(startPos).map((item => {
@@ -235,6 +241,7 @@ class HLSTruncateVod {
         if (this._similarSegItemDuration() && (accDuration - this.durationAudio) >= (this.durationAudio - prevAccDuration) && pos > 1) {
           pos--;
         }
+
         this.audioSegments[audioGroupId][audioLang].items.PlaylistItem = m3u.items.PlaylistItem.slice(startPos, startPos + pos);
         resolve();
       });

diff --git a/spec/hls_truncate_cmaf_spec.js b/spec/hls_truncate_cmaf_spec.js
@@ -290,5 +290,25 @@ describe("HLSTruncateVod", () => {
           done();
         })
     });
+
+    it("cuts to the closest segment when requesting unaligned duration with equal time between them and has start offset", done => {
+      const mockVod = new HLSTruncateVod('http://mock.com/mock.m3u8', 7.5, { offset: 5 });
+
+      mockVod.load(mockMasterManifest, mockMediaManifest, mockAudioManifest)
+        .then(() => {
+          const bandwidths = mockVod.getBandwidths();
+          const videoManifest = mockVod.getMediaManifest(bandwidths[0]);
+          const audioManifest = mockVod.getAudioManifest("audio-aacl-256", "sv");
+          const linesVideo = videoManifest.split("\n");
+          const linesAudio = audioManifest.split("\n");
+          const durationVideo = calcDuration(videoManifest);
+          const durationAudio = calcDuration(audioManifest);
+          expect(durationVideo).toEqual(6);
+          expect(durationAudio).toEqual(7.68);
+          expect(linesVideo[9]).toEqual("test-video=2500000-2.m4s");
+          expect(linesAudio[9]).toEqual("test-audio=256000-2.m4s");
+          done();
+        })
+    });
   });
 });
diff --git a/spec/hls_truncate_spec.js b/spec/hls_truncate_spec.js
@@ -114,8 +114,8 @@ describe("HLSTruncateVod for muxed TS HLS Vods", () => {
         const bandwidths = mockVod.getBandwidths();
         const manifest = mockVod.getMediaManifest(bandwidths[0]);
         const lines = manifest.split("\n");
-        expect(lines[8]).toEqual("segment5_0_av.ts");
-        expect(lines[10]).toEqual("segment6_0_av.ts");
+        expect(lines[8]).toEqual("segment4_0_av.ts");
+        expect(lines[10]).toEqual("segment5_0_av.ts");
         const duration = calcDuration(manifest);
         expect(duration).toEqual(6);
         done();
@@ -203,15 +203,15 @@ describe("HLSTruncateVod,", () => {
           const bandwidths = mockVod.getBandwidths();
           const manifest = mockVod.getMediaManifest(bandwidths[0]);
           const lines = manifest.split("\n");
-          expect(lines[8]).toEqual("level1/seg_37.ts");
-          expect(lines[11]).toEqual("level1/seg_38.ts");
+          expect(lines[8]).toEqual("level1/seg_36.ts");
+          expect(lines[11]).toEqual("level1/seg_37.ts");
           const duration = calcDuration(manifest);
           expect(duration).toEqual(30.03);
 
           const audioManifest = mockVod.getAudioManifest("aac", "en");
           const audioLines = audioManifest.split("\n");
-          expect(audioLines[8]).toEqual("audio/seg_en_37.ts");
-          expect(audioLines[11]).toEqual("audio/seg_en_38.ts");
+          expect(audioLines[8]).toEqual("audio/seg_en_36.ts");
+          expect(audioLines[11]).toEqual("audio/seg_en_37.ts");
           done();
         })
     });