Remux overlapping AAC samples so that they are appended over earlier …

…samples segment rather them dropping them

src/remux/mp4-remuxer.ts

@@ -747,8 +747,9 @@ export default class MP4Remuxer implements Remuxer {
     // frame.
 
     if (track.isAAC) {
+      const alignedWithVideo = videoTimeOffset !== undefined;
       const maxAudioFramesDrift = this.config.maxAudioFramesDrift;
-      for (let i = 0, nextPts = nextAudioPts; i < inputSamples.length; ) {
+      for (let i = 0, nextPts = nextAudioPts; i < inputSamples.length; i++) {
         // First, let's see how far off this frame is from where we expect it to be
         const sample = inputSamples[i];
         const pts = sample.pts;
@@ -758,29 +759,19 @@ export default class MP4Remuxer implements Remuxer {
         // When remuxing with video, if we're overlapping by more than a duration, drop this sample to stay in sync
         if (
           delta <= -maxAudioFramesDrift * inputSampleDuration &&
-          videoTimeOffset !== undefined
+          alignedWithVideo
         ) {
-          if (contiguous || i > 0) {
-            logger.warn(
-              `[mp4-remuxer]: Dropping 1 audio frame @ ${(
-                nextPts / inputTimeScale
-              ).toFixed(3)}s due to ${Math.round(duration)} ms overlap.`
-            );
-            inputSamples.splice(i, 1);
-            // Don't touch nextPtsNorm or i
-          } else {
-            // When changing qualities we can't trust that audio has been appended up to nextAudioPts
-            // Warn about the overlap but do not drop samples as that can introduce buffer gaps
+          if (i === 0) {
             logger.warn(
               `Audio frame @ ${(pts / inputTimeScale).toFixed(
                 3
               )}s overlaps nextAudioPts by ${Math.round(
                 (1000 * delta) / inputTimeScale
               )} ms.`
             );
-            nextPts = pts + inputSampleDuration;
-            i++;
+            this.nextAudioPts = nextAudioPts = pts;
           }
+          nextPts = pts;
         } // eslint-disable-line brace-style
 
         // Insert missing frames if:
@@ -791,7 +782,7 @@ export default class MP4Remuxer implements Remuxer {
         else if (
           delta >= maxAudioFramesDrift * inputSampleDuration &&
           duration < MAX_SILENT_FRAME_DURATION &&
-          videoTimeOffset !== undefined
+          alignedWithVideo
         ) {
           const missing = Math.floor(delta / inputSampleDuration);
           // Adjust nextPts so that silent samples are aligned with media pts. This will prevent media samples from
@@ -824,17 +815,9 @@ export default class MP4Remuxer implements Remuxer {
             nextPts += inputSampleDuration;
             i++;
           }
-
-          // Adjust sample to next expected pts
-          sample.pts = sample.dts = nextPts;
-          nextPts += inputSampleDuration;
-          i++;
-        } else {
-          // Otherwise, just adjust pts
-          sample.pts = sample.dts = nextPts;
-          nextPts += inputSampleDuration;
-          i++;
         }
+        sample.pts = sample.dts = nextPts;
+        nextPts += inputSampleDuration;
       }
     }
     let firstPTS: number | null = null;