fix: force negative frame durations to zero (#769)

Non monotonic streams can produce negative sample duration and result in RangeError: "value" argument is out of bounds. This isn't correct behaviour, but by setting the duration to zero a crash is prevented. Fixes #294 Fixes #652 Co-authored-by: Alexander Kharkov <[email protected]>
AxisCommunications · Apr 8, 2024 · e6773e7 · e6773e7
1 parent 18c26c4
commit e6773e7
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/streams/src/components/mp4muxer/helpers/boxbuilder.ts b/streams/src/components/mp4muxer/helpers/boxbuilder.ts
@@ -218,9 +218,11 @@ export class BoxBuilder {
     // The RTP timestamps are unsigned 32 bit and will overflow
     // at some point. We can guard against the overflow by ORing with 0,
     // which will bring any difference back into signed 32-bit domain.
+    // If the duration would be negative, it's set to zero to prevent
+    // possible issues later when it's written as an unsigned int.
     const duration =
       trackData.lastTimestamp !== 0
-        ? (timestamp - trackData.lastTimestamp) | 0
+        ? Math.max(0, (timestamp - trackData.lastTimestamp) | 0)
         : trackData.defaultFrameDuration
 
     trackData.lastTimestamp = timestamp